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#apertus IRC Channel Logs

2013/09/02

Timezone: UTC


10:09
se6astian
joined the channel
10:32
NeillA
joined the channel
10:33
se6astian
Hi Neill
10:33
NeillA
Hello
10:39
se6astian
did you dig out your zedboard? :)
10:40
NeillA
Not yet
11:42
sashacohen
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11:44
sashacohen
changed nick to: sasha-w
11:44
sasha-w
left the channel
12:05
ApertusWeb7
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12:05
sasha-w
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12:09
ApertusWeb7
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12:49
se6astian
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13:08
Bertl
morning everyone!
13:26
NeillA
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13:28
se6astian
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13:28
sasha-w
Good morning/afternoon/evening everyone
13:29
dmj_nova
good morning all!
13:29
dmj_nova
meeting is in 30 minutes, yes?
13:35
NeillA
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13:35
ApertusWeb0
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13:35
sasha-w
Yep, I believe it is
13:36
Bertl
at least planned, last time it took more than half an hour to gather the folks :)
13:37
Bertl
btw, hello sasha-w!
13:38
sasha-w
Hi Bertl :)
13:39
apertus
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13:40
se6astian
Hello everyone, good to see the channel filling up already :)
13:40
se6astian
20 minutes to go
13:40
ApertusWeb0
left the channel
13:41
apertus
changed nick to: michealg
13:42
Bertl
welcome michealg!
13:42
michealg
Hello!
13:43
philippejadin
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13:44
michealg
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13:44
michealg_
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13:44
Bertl
hello philippejadin!
13:48
michealg_
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13:49
Mich3alG
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13:49
Mich3alG
I keep getting disconnected. My apologies.
13:53
sasha-w
Here is some pre-meeting reading material: http://blackbettycameras.com/first-camera/
13:54
Mich3alG
left the channel
13:54
se6astian
when nofilmschool announced the exclusive release of a new cinema camera a lot of people thought it was us ;)
13:58
sasha-w
How do you know that a lot of people thought it was us?
14:02
dmj_nova
We can do better than that
14:02
se6astian
https://twitter.com/stephenbrock/status/372857914454593536
14:03
se6astian
http://nofilmschool.com/2013/08/new-digital-cinema-camera-exclusive/comment-page-1/#comment-442458
14:06
se6astian
So I just sent you invitations to a google doc
14:06
se6astian
please check if anyone didnt get one and let me know
14:09
sasha-w
Received and reading through it now
14:09
se6astian
perfect
14:09
se6astian
take your time
14:09
dmj_nova
got it
14:09
se6astian
this meeting is an experiment, discussing three dimentional shapes with text chat is a challenge and I dont know what the outcome will be :)
14:09
philippejadin
got it as well, some ideas :
14:10
philippejadin
- allow different battery mount (is it sony on the drawings?)
14:10
philippejadin
- allow customisable button labels
14:10
philippejadin
(so the buttons can be used for different, user-choosable, purpose)
14:10
dmj_nova
I think we should use DSLRs as a model, though we will have to adapt the particulars to cinema usage.
14:11
Bertl
philippejadin: please elaborate on how to customize the labels (note: I'm all for it)
14:11
dmj_nova
The thing with DSLRs (for pro photography purposes) is that they are designed as a tool that can be used mostly by feel.
14:12
dmj_nova
That means physical controls for all of the essential functions right beneath the fingers of the right hand
14:13
se6astian
ok let me make a list of topics to discuss directly in the google doc
14:13
se6astian
1. re-label-able buttons
14:13
philippejadin
Bertl: for example, let's say there are 4 rotary knobs, I'd like to be able to setup the camera to have one knob with iso, second with shutter, third with framerate, etc.... The knob could be around a small lcd that shows the function of each knob, and the current value of eah parameter (iso, fps, etc)
14:13
se6astian
with the dictator I long had the dream that it could be a universal device that could be used to control/remote control a wide range of devices and tool
14:13
se6astian
s
14:14
se6astian
but the further I designed it to be Axiom specific the more it lost its general purpose application
14:14
se6astian
philippejadin, actually the dictator works exactly that way, look at the LCD in the last image
14:15
dmj_nova
the dictator as shown in the last render I feel isn't that great ergonomically
14:15
Bertl
philippejadin: small LCDs are usually a bad choice, unless you add a backlight, in which case, you can go for OLED displays, but in any case, this requires lots of space, power and adds a lot of hardware
14:15
philippejadin
do we want to have a live viewfinder as well, or is the screen only used to show camera menu ?
14:15
Bertl
OTOH, if the knobs are nearby an existing LCD/TFT/OLED display, it can be use for dynamic labeling as well
14:16
philippejadin
Bertl: exactly wha tI was thinking
14:17
philippejadin
in fact the current layout is good
14:17
philippejadin
would be nicer to have 4 knobs
14:17
Bertl
although it adds mechanical stuff (which can easily break, again uses up valuable space and complicates things) I consider the concept of rotary buttons a good UI
14:17
Bertl
if we just want 'buttons', I'd suggest to make them virtual
14:18
dmj_nova
anyone familiar with the thumbwheel on modern dslrs?
14:18
philippejadin
what you keep changing on a shooting is iso, shutter, white balance
14:18
dmj_nova
no, we want physical buttons
14:18
se6astian
the 2 rotary encoders on the current concept can also be pushed which opens a menu on the LCD to choose which value this wheel should change
14:18
philippejadin
with physical knobs, once you are used to them, you don't even have to look at them, you can change a setting without looking at a menu. in documentary setup it's a must
14:19
dmj_nova
at least for key things like iso, shutter speed, aperture, etc
14:19
dmj_nova
philippejadin: yes, exactly
14:19
Bertl
se6astian: do we have some specific hardware in mind or is that just a concept idea?
14:19
dmj_nova
we should design a tool which can be operated without looking or moving one's hand from the grip
14:20
Mich3alG
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14:20
Bertl
how do you know that you got the right setting? (without overlay in the viewfinder) or can this be assumed?
14:21
Bertl
because if we assume a viewfinder with some kind of overlay, we could probably drop the display on the side completely, no?
14:21
Bertl
(or is the display on the side the viewfinder?)
14:22
philippejadin
if we can have both it's even better
14:22
se6astian
Bertl, specific hardware: http://www.youtube.com/watch?v=y2mAKEdNUVg
14:22
dmj_nova
Bertl: well, if you knew what it was before/you're monitoring the output (and are going for look)/you can see the screen that list vital stats
14:22
se6astian
arduino plus 320x240 2.8" touchscreen LCD plus a bunch of butons and knobs
14:22
philippejadin
sometimes some settings are changed by the camera ssistant,but the director wants to know what others are doing, so having feedback in the viewfinder (video out) is nice
14:23
Bertl
se6astian: where are the turnable knobs?
14:23
se6astian
not in the prototype breadboard yet
14:23
philippejadin
the assistant is for example at the left of the camera, and can choose the iso on the camera, and have some feedback on screen
14:23
dmj_nova
se6astian: is the dictator planned as video output preview as well?
14:23
se6astian
dmj_nova, no
14:23
philippejadin
This is great design imho : http://www.tangentwave.co.uk/images/wave/wave_top.jpg
14:23
Bertl
se6astian: so no specific knob or device tested for this purpose yet?
14:23
dmj_nova
okay, then 320x240 is fine
14:24
se6astian
Bertl, I bought a bunch of rotary encoders and knobs but didnt implement them yet
14:25
Bertl
okay, sidenote: please gather them together and give them to me for further inspection :)
14:25
dmj_nova
Bertl: if I need to see the exact value there's a small LCD on the top of my DSLR that tells me. Could completely ignore everything but the physical controls and that little LCD if I wanted
14:26
philippejadin
dmj_nova: exactly
14:26
dmj_nova
philippejadin: that link doesn't seem to work
14:26
se6astian
Bertl, will do :)
14:26
Bertl
dmj_nova: works here
14:26
philippejadin
another interaction with the knobs could be tu push them. It could either lock the setting, or provide an auto setting (iso, whitebalance)
14:27
philippejadin
short push : auto, long push (un)lock
14:27
Bertl
philippejadin: that looks like a control unit for video editing?
14:27
philippejadin
Bertl: it's for color grading
14:27
philippejadin
dpeending on where you are in the software, the proper labels are displayed
14:27
Bertl
ah, what are the red balls?
14:28
philippejadin
they are used to change the colors in shadows, middle and highlights areas of the image
14:28
dmj_nova
link just times out for me
14:28
philippejadin
dmj_nova: maybe this page : http://www.tangentwave.co.uk/products_wave.asp
14:29
philippejadin
Bertl: the top part (with knobs and oleds) reminds me of the dictator
14:29
Bertl
dmj_nova: http://vserver.13thfloor.at/Stuff/AXIOM/wave_top.jpg
14:30
sasha-w
I have a question that's off the current topic: What type of cabling will be used to connect the dictator to the axiom body? USB2, USB3?
14:30
sasha-w
Wireless?
14:31
dmj_nova
se6astian: this "wooden handle" is it something we're married to or what's the deal with it?
14:31
Bertl
USB sounds good to me, USB3 probably a good idea if you want to transfer video data as well
14:31
Bertl
wireless not so good, but can be done via usb as well, if the connection can handle a wireless dongle
14:31
se6astian
sasha-w, wireless or serial interface cable so could be USB or lemo connector
14:32
dmj_nova
philippejadin: do you use DSLRs/pro cinema cameras for video?
14:32
philippejadin
another classic (for me:-) , the sony Z1 : http://1.bp.blogspot.com/_axRvOJ27Ph0/TNP00sxkrCI/AAAAAAAAAAc/KfC1sUcgvPE/s1600/39601.jpg
14:33
se6astian
dmj_nova, the wooden handle was inspired by http://www.aaton.com/images/penelope5.jpg - if we add buttons controls to it it will be something new
14:33
Bertl
@"wooden handle", I think it could be a signature element for the axiom, but I'd definitely make it exchangeable
14:33
Mich3alG
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14:33
Mich3alG
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14:33
philippejadin
dmj_nova: I already used quite some, I guess like others (PD170, Z1, EX3, Red one & scarlet, 5D, GH1)
14:34
dmj_nova
philippejadin: what are your thoughts on their ergonomics?
14:34
dmj_nova
what are the distinguishing ergonomic features of purpose cinema cameras
14:35
dmj_nova
where do DSLRs excel/fall down for you?
14:35
Mich3alG
My favorite camera from an ergonomics perspective is the Arri Alexa
14:35
dmj_nova
I have some possible thoughts here, but we need to listen to pro cinematographers foremost
14:35
dmj_nova
Mich3alG: why?
14:36
Bertl
@"knobs/buttons at handle": there was a controller called 'the claw' (many years ago, http://www.dansdata.com/claw.htm)
14:37
se6astian
the claw, perfect :)
14:37
Bertl
it worked surprisingly well, despite the bad quality and clumsy design
14:37
Mich3alG
dmj_nova It feels like their old 35mm film cameras. It feels like an actual cinema camera. When you put it on your shoulder, it has weight that allows for smoother shots
14:37
se6astian
the only problem I see with the claw like design for us is that you often "just" want to hold the camera with one hand without pressing any buttons, so the claw is rather designed for desktop use
14:38
dmj_nova
se6astian: DSLRs are basically a claw for thumb and forefinger
14:38
se6astian
exactly, we need to limit our butons/controls to two fingers so the other 3 can have a tight grip
14:39
Bertl
I was more thinking of putting a button for each finger on the grip (which, of course, can be customized and disabled)
14:39
dmj_nova
you use the other three fingers and corner of your hand for support
14:39
dmj_nova
the thumb, being free to move can operate several functions if there is a distinct feel to each
14:40
Bertl
there are other alternatives as well, for example tiny joy sticks or tiltable buttons (like the side tilt on the scroll wheel)
14:40
Bertl
and many more, the main question is more do we want that at all, or do we plan that as add-on ...
14:41
sasha-w
I would suggest taking a look at the ergonomics of the pentax k7 and K5. Very good button layout, with quick access for all necessary functions
14:41
Bertl
(because it needs to be connected somehow to the camera :)
14:41
se6astian
Bertl, its all an addon :)
14:42
dmj_nova
I've not used pentax, Canon models (pro ones, not the rebels) have good ergonomics
14:42
sasha-w
http://www.thephoblographer.com/2010/12/14/field-review-the-pentax-k-5-day-1/
14:42
sasha-w
Scroll down to the button layout section
14:42
Mich3alG
My least favorite cameras to use are the Red Epic/Scarlet. I do like the C300 and it's side grip/ controls
14:43
philippejadin
I second that, red scarlet is pita
14:43
NeillA
left the channel
14:43
philippejadin
just to change the iso, if you don't have the touch screen connected, you have to navigate the menu with the four buttons
14:44
philippejadin
(not to mention that I inadvenrtenly put the menu on the wrong output, and we didn't have a creen with the appropriate connector, so I had no menu to change the settings, had to wildguess :-) )
14:46
dmj_nova
Mich3alG: like this? http://blog.planet5d.com/wp-content/uploads/Canon-C300-test-shoot-1.jpg
14:46
dmj_nova
that looks like somebody basically made the C300 a giant dslr
14:47
se6astian
OK, so to summarize: I will create a concept for the wooden handle with buttons/controls and present it to you
14:47
Bertl
okay, I think many aspects we are discussing do not really depend on the hardware design and should be postponed (i.e. menu/gui/etc)
14:47
sasha-w
dmj_nova: I've used Canons too, but something keeps making me go back to the pentax for its customizable, dual control dials. They allow me to control the camera exactly how I'm naturally inclined to
14:47
dmj_nova
physical device is the most important to get right
14:47
se6astian
I would suggest we discuss what the concept shows already not what it does not show yet
14:47
se6astian
I would be interested in feedback about the images you see in the google doc
14:48
Bertl
can we have page numbers?
14:48
se6astian
in the google doc?
14:48
Bertl
yup
14:48
se6astian
done
14:48
Bertl
great! thanks!
14:49
Bertl
looking at page 3 atm
14:49
Bertl
i.e. the most recent? sensor frontend design
14:49
Mich3alG
left the channel
14:49
se6astian
check the headers
14:49
se6astian
it goes from 2012 -2013
14:50
Bertl
now page 4 :)
14:50
philippejadin
Wouldn't it be better to have a flat surface on the sensor side (instead of round shape)
14:50
Bertl
now page 3 again :)
14:50
Mich3alG
joined the channel
14:51
se6astian
added page breaks
14:51
se6astian
now every "version" has its own page
14:51
Bertl
(page 4 now seems to be left blank for notes)
14:51
dmj_nova
se6astian: are you familiar with the thumbwheel on pro DSLRs?
14:51
se6astian
hmm, not here...
14:51
se6astian
dmj_nova, sure
14:52
se6astian
philippejadin, what is the "sensor side" ?
14:52
Bertl
http://www.cinema5d.com/wp-content/uploads/2012/07/Screen-Shot-2012-07-12-at-20.13.34.png
14:52
dmj_nova
and I'm not sure if pentax does it the same way, but all menus and relevant settings can be adjusted via the thumbwheel and the rotary wheel behind the shutter button
14:53
philippejadin
se6astian: the front of the camera let's say
14:53
Bertl
this is what I'd like to focus on for a moment
14:54
Bertl
I call this the sensor frontend although it will contain much more than just the sensor
14:54
Bertl
(note: we should find proper names for the parts)
14:56
sasha-w
Bertl: As far as I'm aware, the SFE won't have any buttons. What are you thinking here in terms of ergonomics? Are you proposing a different shape for the final design?
14:57
Bertl
no, I just want to discuss how that connects to the rest of the camera
14:57
dmj_nova
so for user serviceability I'd propose the sensor frontend block push into the full body through the front, then a front plate attaches over it and holds it in place.
14:57
philippejadin
with the recent advances in capabilities we can expect from boards, we can assume the camera and the recorder will be in the same box (even if this box is made of separate parts)
14:58
dmj_nova
that would leave sides/back free for connectivity and controls
14:58
Bertl
philippejadin: yes and no, basically we have at least three technical challenges to handle:
14:59
Bertl
1) the sensor should be kept cool and free of any disturbance/noise
14:59
Bertl
2) we need to move a lot of data from the sensor to the FPGA and from FPGA to the interfaces
15:00
Bertl
3) increased computing power increases power consumption and heat produced
15:00
dmj_nova
heat is our biggest enemy :P
15:00
Bertl
so, packing everything together will give you a noisy whater heater :)
15:00
Bertl
*water
15:01
sasha-w
The dictator, monitor, hdd, battery and audio hardware all have to come together somehow to form a single functioning unit. Previously, I had toyed with the idea of having all of these connect to a small computer (like a mac mini) and creating some kind of shell not unlike the black betty camera
15:01
philippejadin
we could make it more modular, a cube containing sensor and processing, with sata, sdi, hdmi, power
15:01
philippejadin
on the red one, the harddisk was a separate unit you had to attach to a rail
15:01
philippejadin
same for power
15:02
se6astian
what parts will generate the most heat? the image sensor draws around 4W, the zynq will draw a few watts as well, anything else?
15:02
Bertl
philippejadin: yup, but separating (some) parts gives the problem that we need to transport the data between them
15:02
philippejadin
we can assume that only field tested system (connections) can be separated
15:03
Bertl
se6astian: FPGA (zynq), voltage regulators, ImageSensor, serializers (IMHO in this order)
15:03
philippejadin
sensor and processing board must stay together (fmc?), altough cool
15:03
dmj_nova
well, since we need sata interfaces anyway for the SSDs, those can be a separate unit
15:03
dmj_nova
yes
15:04
philippejadin
Bertl: do you think we'll need fans ?
15:04
Bertl
yes, if we want sata, the disks can and should go somewhere else
15:04
Bertl
philippejadin: maybe, maybe not, mostly depends on the design
15:04
Bertl
moving parts are always using up a lot of space and usually die soon (i.e. cause a lot of grief)
15:05
Bertl
for example, the metal block of the 'SFE' could be used to cool down the sensor (to some degree)
15:05
philippejadin
I ask that because red didn"t manage to work without fan
15:06
Bertl
there could be some kind of cooling fins on it too
15:06
dmj_nova
well, if the body is metal
15:06
Bertl
let me give a few numbers to get an idea what we have to handle:
15:06
dmj_nova
and we can get good thermal connection with it
15:06
Mich3alG
Ideally the SSDs should be slot mounted like the Red cameras/ Blackmagic
15:06
Bertl
the sensor should stay as cool as possible, i.e. room temperature or below
15:07
dmj_nova
I do like the SSD mounting shown in the doc
15:07
Bertl
the FPGA OTOH, can go up to 60°C without any problems
15:07
sasha-w
agreed
15:07
Bertl
(probably even more)
15:08
dmj_nova
Bertl: so perhaps we can thermally isolate the two?
15:08
Bertl
for example
15:08
dmj_nova
provide much more metal surface area to cooling the sensor?
15:08
Bertl
we also want to avoid any noise (EM) from the FPGA and serializers to hit the sensor
15:09
Bertl
another quite important question is: do we want to have different sensors?
15:09
dmj_nova
Bertl: I think we want to allow different sensors
15:10
dmj_nova
sensor tech will advance faster than we must replace the FPGA
15:10
Bertl
this IMHO affects the design of the interfaces and the case, because it needs to be standartized in some way
15:10
se6astian
yes, at an undefined point in the future
15:11
Bertl
philippejadin: the problem with physically separating parts is this:
15:11
Bertl
we need to transport lots of data, which requires high speed communication, which in turn adds communication devices, which in turn draw power and generate heat
15:12
Bertl
so simplest case, everything on one board (not practicable)
15:12
Bertl
no 'internal' data juggling/transfer required here, all power/heat will be minimal
15:13
Bertl
the other extreme is to separate everything, i.e. SFE, FPGA, (G)UI, etc
15:13
Bertl
this will add communication overhead and the higher the speed, the more power is required and heat is generated
15:14
philippejadin
That's why I was thinking, only separate things that can be separated, which I think is sata for harddisk, and hdmi / sdi for screen. The rest can be on a single board
15:14
Bertl
I know that this sounds like technical problems (and those are indeed technical problems) but the very much affect the design :)
15:15
Bertl
philippejadin: sounds good, but probably is impractical as well, you don't want a 8 by 8 inch board with the sensor in the middle, no?
15:16
Bertl
(or even worse, with the sensor on one edge :)
15:16
dmj_nova
most likely we'll need a sensor board and an FPGA board, yes?
15:16
philippejadin
I was thinking a T shaped system, with 2 boards
15:16
philippejadin
sensor frontend + processing board
15:16
Bertl
T shaped, like the weiss cam? sounds like a good idea
15:17
philippejadin
at least the connection between the two boards
15:17
Bertl
dmj_nova: yes, at least
15:17
Bertl
dmj_nova: I'd add an interface (I/O) board as well
15:17
se6astian
More L than T in our case but yes ;)
15:18
dmj_nova
I might actually suggest a sandwich config
15:18
sasha-w
I'd avoid anything that might make people think we're ripping off ideas from Weisscam
15:18
Bertl
stacking boards and connecting boards helps with a lot of things, like for example isolation, but it also 'steals away' a lot of space for the connections
15:19
Mich3alG
left the channel
15:19
dmj_nova
sasha-w: what's the issue with weisscam?
15:19
Bertl
for example, the sensor CMV12k we are considering, has 67 differential lines
15:20
Bertl
that means at least 140 conenctions, but for EM reasons, it will be more like 280 or 300
15:20
Bertl
(and that is not considering the power supply lines)
15:20
sasha-w
No issue, just I don't think it looks good from a public relations perspective. People might think we're unoriginal and have to resort to stealing another company's design. Plus, Weiscamm could potentially come after us if we release something that looks like a carbon copy of their proposed 'T-Camera'
15:20
Bertl
that's a lot of space, as you can easily see on the prototype boards
15:21
dmj_nova
Bertl: so will we need a 2D plane or a single line of connection for interfacing sensor and FPGA boards?
15:21
dmj_nova
socket or ribbon basically?
15:22
Bertl
yes
15:22
philippejadin
fmc connectors might exist in 90°
15:22
Bertl
not as far as I know, and FMC is probably not the best choice anyway
15:22
dmj_nova
sasha-w: don't like their t-cam look much anyway
15:23
Bertl
philippejadin: but we'll find a connector suitable for this purpose
15:23
se6astian
there is no 90° FMC connector
15:23
Bertl
the problem with the 90° board-to-board is more the small connection area
15:23
se6astian
what densities, lane counts can we expect from standard B2B connectors?
15:24
Bertl
i.e. you have to put the connections in 1-3 rows
15:24
dmj_nova
what about a cable? or is that no good?
15:24
Bertl
conenctors go down to 0.2 mm (flexible) and usually 0.5 mm rigid
15:25
Bertl
but we have another problem there, the electrical impedance
15:25
Bertl
at high data rates, we need to match the impedance if we do not want to degrade the signal
15:26
Bertl
(which means we need specific lane widths and spacing (and ground connections)
15:26
dmj_nova
how much spacing could we put between boards with a parallel board configuration?
15:26
Bertl
I know that's somewhat technical again, but basically it means that we can not reduce the connector arbitrarily
15:26
philippejadin
when we met the guy at cmosis, he told us that flexible cabling would not be a good option, because cable lenghts must be matched to have the same signal strenghts / speed / impedance
15:27
dmj_nova
basically, how thick can a "socket" be?
15:27
Bertl
dmj_nova: depends on the connection, usually stacked boards have a distance between 6 and 16mm
15:27
Bertl
up to an inch @300MHz can be considered harmless (that's sensor to FPGA)
15:27
dmj_nova
wondering if we can jam heat sink or pipes between that
15:28
Bertl
question to the 'camera users': would you mind if some (which?) parts of the camera get really hot?
15:29
dmj_nova
so you have a sensor board + heat spreader + FPGA sandwich
15:29
dmj_nova
Bertl: I'd say we should avoid any parts getting "hot"
15:30
philippejadin
Bertl: I don't think it's an issue if the camera gets hot. Maybe if the part is near batteries
15:30
dmj_nova
I wouldn't want the handle or back getting hot though
15:30
philippejadin
I'd better have a hot comera that's silent
15:30
Bertl
well, that's why I'm asking, because, for example, we could cool down the sensor with a peltier element, which would heat up a heat spreader at the other end
15:30
sasha-w
How hot are you talking about? As long as I could still hold it with barehands, then no problem
15:30
dmj_nova
(should be comfortable to hold, nothing should be painful to touch
15:31
Bertl
I'm talking 60 degrees celsius and up
15:31
dmj_nova
Bertl: that said, if the SFE block gets hot it's fine
15:31
dmj_nova
as long as the body spreads that heat effectively
15:32
Bertl
which brings the next question, what about cooling fins all over the FE case?
15:32
sasha-w
If we still want an optical viewfinder at some point (not sure how likely that will be now), would it be dangerous to have your head / eyes close to the body at this temp?
15:32
dmj_nova
Hmm, so the cooling fins could actually help the FE case to slot into the body
15:33
dmj_nova
sasha-w: yes, unless you route the heat from the peltier cooler to the viewfinder
15:33
Bertl
possible, yes, so from a technical PoV, I'd make the entire FE a big heat spreader with lots of cooling fins
15:34
dmj_nova
sasha-w: the optical viewfinder/mirror setup would go just in front of the FE unit, I'd guess
15:34
philippejadin
on the red scarlet, (like here http://www.thefilmmakersworkshop.com/wp-content/uploads/2012/05/Scarlet-X-1.png) it works like that : there is a fan at the front that takes fresh air and exhausts it at the top (on the back of the camera).
15:35
Bertl
http://buy.traxxas.com/images/products/1522.jpg
15:35
sasha-w
yeah, with the eyepiece running along the side of the camera. The camera could be positioned on your shoulder and still allow you to look through an eyepiece
15:36
Bertl
philippejadin: yes, this is a good choice as well, the fan in the front, cooling the sensor first and exhaust at the top AFAICT from the picture
15:37
dmj_nova
sasha-w: though I imagine an electronic viewfinder would be more practical for a cinema camera
15:37
Bertl
what I mean is, we should design with maximum cooling in mind
15:37
dmj_nova
Let's avoid fans and air intake if possible
15:38
dmj_nova
a watertight design is much preferred
15:38
Bertl
because that will improve image quality and reduce noise
15:38
philippejadin
My take is that if red didn't manage to remove the fans, we'll have hard times as well
15:38
dmj_nova
Bertl: can a peltier function passively as a regular heatsink?
15:38
Bertl
yes, but it is a quite bad heat sink
15:39
Bertl
as it will generate electricity instead :)
15:39
sasha-w
dmj_nova: different horses for different courses.... ;)
15:39
dmj_nova
ah
15:39
Bertl
underwater cooling isn't a problem :)
15:39
sasha-w
dmj_nova: Optical viewfinder makes things onset go a bit quicker. There's no reliance on battery power and you can set up shots in a fraction of the time.With that said electronic viewfinders allow for peaking and exposure levels to be visible...
15:40
philippejadin
how the red works : while shooting, the camera gets perfectly silent, and as soon as you press stop, it makes a lot of fan noise to reduce temp. sometimes the camera even stops, because it gets to higher than 70° (which is afaik the limit on this camera)
15:40
dmj_nova
philippejadin: that sounds really awful
15:41
dmj_nova
not knowing when the camera will stop on you
15:41
philippejadin
or the fan starts while you shoot after a while, and everyone looks at the camera asking, what's going on :-)
15:41
sasha-w
[hillipejadin: do you have to be careful when handling the camera at this temp? Do you wear gloves?
15:41
philippejadin
sasha-w: no, I think it's internal temp
15:41
dmj_nova
sasha-w: I imagine that is the temp at the sensor
15:41
philippejadin
more likely on the cpu
15:42
philippejadin
the camera is calibrated for a particular temperature range
15:42
philippejadin
if the temperature is 5° different then last calibration, you have to clibrate it again
15:42
philippejadin
(well, you are supposed to)
15:43
philippejadin
sensor is at around 30° or something
15:43
dmj_nova
there are passive coolers for GPUs
15:43
philippejadin
maybe it's the price to pay for higher dynamic range?
15:43
dmj_nova
gives me some hope that we can as well
15:44
Bertl
yeah, well, the heat has to go somewhere
15:44
dmj_nova
philippejadin: now if the temperature changes and then changes back will the calibration be fine?
15:44
Bertl
but maybe we can take a green approach and actually recover some of the heat as energy
15:46
sasha-w
Bertl: Where would you route this energy?
15:46
Bertl
this is where peltiers could come into play as heatspreader
15:46
dmj_nova
Perhaps we can test with thermal mockups and find out more concrete answers?
15:47
Bertl
i.e. the difference between internal temperature and external temperature could generate electricity
15:47
dmj_nova
that could be quite interesting if it doesn't make the thing to bulky/heavy
15:47
Bertl
yeah, that's probably the downsinde, peltiers are somewhat heavy
15:48
Bertl
so, to get back to the design part, what about cooling fins all over the camera front?
15:49
Bertl
what about cooling fins all over the camera (except the display and handle part of course)
15:49
Bertl
s/display/interface/
15:49
philippejadin
the bottom must be very sturdy
15:50
dmj_nova
Bertl: I'd say no to the fins on the camera front
15:50
philippejadin
to attach it to a tripod
15:50
Bertl
that's a well defined connector IIRC
15:50
dmj_nova
Bertl: my guess is that we can probably not actually have fins on the outside of the body
15:51
dmj_nova
but have fins all over only on the SFE unit (with negative fins on the inside of the body where the SFE slots in)
15:51
Bertl
well, that would be bad from the thermal PoV, as a smooth surface has little heat spreading capability
15:51
dmj_nova
philippejadin: Bertl: to my knowledge that's a fairly standard quarter inch bolt
15:52
dmj_nova
Bertl: the camera body being the handle and everything else
15:52
philippejadin
dmj_nova: yes, but mecanically the surface would be better flat, so it sticks to the tripod plate
15:52
dmj_nova
so much bigger than the SFE block
15:53
Bertl
also note, that I'm not so worried about the bottom
15:53
philippejadin
in fact, we need to know how big the sensor frontend and the other boards will be, and how they will connect to each other
15:53
Bertl
heat tends to dissipate up, so the top is important, and the sides are interesting
15:54
philippejadin
the original idea was to have two board in sandwich, roughtly 7 by 7 cm iirc
15:54
philippejadin
but if we like black betchy desing, it could be one small sensor board and a bigger one for processing
15:54
philippejadin
I guess bigger = easier to cool
15:54
Bertl
that's fine for the sensor board IMHO (7x7cm)
15:55
philippejadin
a low speed fan could be used
15:55
Bertl
the current adapter is 63x71mm
15:55
philippejadin
but the bigger the fan air input, the more risk with dust and everything
15:55
philippejadin
or the can could be mounted outside of the camera
15:55
philippejadin
or we could use a box in a box model ?
15:55
Bertl
so a sensor like the CMV12k can be placed on a 60x60mm board in the middle, still having room for the connections on the sides
15:55
dmj_nova
hmm
15:56
dmj_nova
so about fans/etc
15:56
philippejadin
priority is image quality, so if a fan is needed, so will be :-/
15:57
dmj_nova
if the SFE had a heat fins, we could make the SFE itself watertight and blow air over the fins
15:57
dmj_nova
this couples cooling to the body design, not the SFE block
15:57
dmj_nova
I'd rather not blow air through the SFE block
15:58
dmj_nova
philippejadin: well, we need both image quality and good ergonomics so it's usable.
15:58
Bertl
a nice concept might be having heat pipes going from bottom to top and maybe even slots/holes going through the SFE to externally cool the block
15:58
Bertl
the fan could be an add-on attached to the top of the camera?
15:59
philippejadin
from the sensor datasheet, operating range -30 to 70° *but* as they say : "Dark current and noise performance will degrade at higher temperature"
15:59
Bertl
i.e. you decide if you want the better image quality or the silent cam?
15:59
dmj_nova
if you want your sensor below room temp just hook it up to an external AC unit?
15:59
philippejadin
if we want to compete with other cameras, I think we'll want the ideal sensor cooling all the time
16:00
philippejadin
Because dark current = dynamic range
16:00
Bertl
which probably requires a peltier for the sensor anyways (but just one in the right place)
16:00
Bertl
mainly because we want the temperature to be tightly controlled
16:00
dmj_nova
we won't get it to -30 of course without significant sacrifice
16:00
Bertl
doesn't make sense
16:00
philippejadin
of course not
16:01
philippejadin
I guess room temperature is ideal
16:01
Bertl
everything below 5°C is a nightmare electronics wise
16:01
Bertl
because water condenses and destroys it
16:01
philippejadin
or said otherwie, I guess they designed the sensor to perform best at room temp
16:01
philippejadin
(wlid guess of course)
16:02
dmj_nova
Bertl: why not put the peltier in the body?
16:02
sasha-w
Yeah, I had the same question. Surely something like this wouldn't add too much weight: http://www.jaycar.com.au/productView.asp?ID=ZP9100
16:03
dmj_nova
philippejadin: couldn't you just calibrate the sensor for each temperature and adjust profiles automatically based on reported temp?
16:03
philippejadin
sasha-w: 4 amps at 15 v is 60 watts
16:04
philippejadin
dmj_nova: it's just that we'll probably discover that we have good image quality at 20°, decent at 30° and awfull at 60°
16:05
sasha-w
Philippejadin: Forgive me, but what watt range would be ideal here?
16:05
philippejadin
you cannot "calibrate" above some temperature, you'll get higher noise in the blacks
16:05
dmj_nova
sounds like passive cooling would be fine except in hot outdoors
16:05
dmj_nova
at which point you *need* something like peltier
16:05
Bertl
sasha-w: this one is about 16g
16:06
philippejadin
I think in red user guide, they tell about calibration when you work at lower temperatures than room (not higher)
16:06
dmj_nova
philippejadin: what does the calibration do?
16:07
philippejadin
sasha-w: depending on the batteries we have we can hope to have 90w batteries (pretty big stuff already). It means that we would use one battery like that in 1:30 hour just for cooling (Bertl correct me if I'm wrong)
16:08
philippejadin
dmj_nova: they call it black calibration (explained here : http://www.red.com/learn/red-101/black-shading-calibration)
16:09
Bertl
philippejadin: depends on the actual cooling, the peltier is quite efficient, so for let's say 5W heat generated, we need maybe 8-10W to cool it down
16:09
Bertl
so it doesn't always use up the maximum
16:10
Bertl
and it can provide heat to sensor as well (in theory)
16:10
philippejadin
It would be nice to keep in mind the max power use of the camera. If it's 50w it's great, but will we manage that? Sensor + processing + ssd
16:11
dmj_nova
philippejadin: so I'd guess you could store a range of calibrated profiles and use the one that matches the sensor's current temperature best
16:11
Bertl
what ssd(s) is(are) planned?
16:11
Bertl
1.8" 2.5" ?
16:11
philippejadin
dmj_nova: to the extend that lower temp is better, yes
16:11
se6astian
1.8"
16:12
Bertl
so you probably want high speed, i.e. 250MB/s and up?
16:12
dmj_nova
Bertl: We'll need to
16:13
Bertl
that roughly add 2-3 watt per drive
16:13
se6astian
quite reasonable
16:15
Bertl
so the zynq for example should max out at 30W
16:16
Bertl
(the power there depends on what we actually do)
16:16
Bertl
the sensor about 3-5W top
16:16
dmj_nova
so we need to cool and supply 30W of heat/power
16:17
dmj_nova
zync is quite power hungry then
16:17
Bertl
luckily not all is dissipated as heat
16:17
philippejadin
we could manage with 50W I guess then
16:17
dmj_nova
cooling 3-5 watts is not a big issue
16:18
dmj_nova
not an issue at all
16:18
dmj_nova
with that being the case, I expect RED's cooling issues have much more to do with processing power than sensor temp
16:20
Bertl
maybe we could have a slot from top to bottom between then sensor board and the processing/FPGA board
16:21
philippejadin
I gotta go, I hope you'll end up with interesting proposals :-)
16:21
Bertl
okay, cya
16:21
dmj_nova
philippejadin: thanks for the input
16:21
se6astian
see you philippejadin!
16:21
dmj_nova
really helps having pro design feedback
16:23
Bertl
btw, the sensor itself is almost 6cm in width, so below that is a no-go, even for a tiny sensor board
16:23
dmj_nova
Bertl: you mean the whole unit...hmm...that's much bigger than the light sensitive region
16:24
Bertl
yep
16:24
philippejadin
left the channel
16:24
dmj_nova
Bertl: if we're just cooling 5 watts (and not mixing heat from the zync), it will be really easy to cool that to room temp
16:24
se6astian
ok should we close todays meeting, I have to start cooking dinner ;)
16:24
dmj_nova
sounds fine to me
16:25
se6astian
I will summarize everything into the google doc and email everyone
16:25
Bertl
so be it
16:25
se6astian
thanks to everyone for participating!
16:25
sasha-w
Despite the difficulties presented via IRC chat, should we aim to have another meeting here soon
16:26
Bertl
I'd say we'll probably need a few more to get a concept ready
16:26
Bertl
i.e. a concept we can actually build :)
16:27
se6astian
let me visualize the concept before we meet again
16:27
se6astian
but we should definitely do this again
16:28
sasha-w
good to hear. Ok then, bye for now :)
16:29
Bertl
cya
16:29
se6astian
bye!
16:29
Bertl
(feel free to hang around :)
16:29
sasha-w
ok, will do
16:29
sasha-w
for a little while...
16:31
sasha-w
I'm curious about the peltier cooling process. So it draws power from the battery to cool? The way you described it, heat generated by the SFE and CPU hardware could be converted into electrical energy and routed elsewhere
16:41
Bertl
yes, basically a peltier element uses the peltier effect, which works in both directions
16:41
Bertl
i.e. if you have two metals attached to eachother, and a temperature difference between the sides
16:41
Bertl
electricity is generated
16:41
sasha-w
So what Philippe says is correct, and that it will draw power from the batteries?
16:42
Bertl
the reverse is, that you can create a temperature difference between both sides by applying power
16:42
sasha-w
I see, and use power from the battery to cool certain areas. Clever
16:42
Bertl
really depends on how it is used .. for active cooling, it will definitely draw power (roughly twice the amount it has to cool)
16:43
Bertl
between a higher inner temperature and a cold outside temperature it could create electricity
16:43
sasha-w
I interpreted it as converting heat energy to electrical energy, which could be routed elsewhere (like to recharge a secondary battery)
16:45
sasha-w
and the conversion of heat energy into electrical energy would reduce the temp (as heat is being converted into another form of energy)
16:48
Bertl
well, the peltier is not the ultimate cooler, it is more a device which uses electricity to create a temperature difference
16:48
Bertl
or if used the other way round, to generate electricity from a temperature difference
16:49
Bertl
so, while, for example, cooling down the sensor, it will heat up the other side
16:49
sasha-w
I see. Thanks for helping me understand this better :)
16:49
Bertl
(which needs to be cooled down in some other way to keep the difference
16:50
Bertl
)
16:52
Bertl
think of it as an electrical heat pump
16:53
Bertl
(or generator, when heat flows through it)
17:01
sasha-w
Ok, I gotta go now. Chat again soon.
17:01
sasha-w
left the channel
17:20
Bertl
http://vserver.13thfloor.at/Stuff/AXIOM/stacked.png
17:21
Bertl
where the green parts are the PCBs, the brown is the interconnect, yellow is the sensor, blue the peltier and orange the FPGA/etc
17:21
Bertl
the white slot actually goes through the entire body, from bottom to top like a chimney
17:22
Bertl
this could be easily extended by an active fan on the top blowing 'up'
17:23
Bertl
interconnect between the light green boards can be in any direction and probably should not happen at the same position as the sensor to pcb interconnect
17:25
Bertl
the tiny black bars would be inward faced fins from the heat spreaders on peltier and FPGAs
17:26
Bertl
(we are looking at the frontend from above :)
17:37
se6astian
btw red epic cooling: http://www.extremetech.com/wp-content/uploads/2012/01/red-x-mysterium-sensor-behind-heatsink.jpg
17:57
Bertl
what's that mysterium-x sensor?
17:58
se6astian
Reds own image sensor
17:58
se6astian
they make fun of everyone because its super proprietary and they named it "mysterium" ;)
18:09
Bertl
i.c.
18:16
Bertl
btw, I did a little research on rolling shutter vs. global shutter
18:16
Bertl
and it seems that global shutter is preferable (artefact wise) whenever something moves or the camera turns
18:20
dmj_nova
Bertl: yes, it avoids skews from the shutter
18:20
dmj_nova
would also avoid bizarre banding when shooting LEDs and CFLs
18:25
Bertl
so basically the piplined global shutter the CMV12k provides is vastly superior to those sensors using a rolling shutter, yes?
18:25
Bertl
*pipelined*
18:26
dmj_nova
Bertl: assuming similar characteristics otherwise, yes
18:26
Bertl
going through the datasheet, I wonder what the actual LVDS clock rates are
18:28
Bertl
point 3.5 states: The maximum data rate of the output is 300
18:28
Bertl
Mbps which results in an input LVDS_CLK_P/N of 300MHz. The minimum LVDS_CLK_P/N frequency is 300MHz for 12
18:28
Bertl
bit, 150MHz for 10 bit and 100MHz for 8 bit.
18:29
Bertl
but a little further in the datasheet it says:
18:29
Bertl
So when CLK_IN is
18:29
Bertl
30MHz in 10 bit mode with 64 output channels, register 82[15:8] is 23 and register 85 is 128. This will result in a FOT =
18:29
Bertl
107.5μs
18:30
Bertl
do I understand that correctly that CLK_IN is not the LVDS clock?
18:34
Bertl
yeah, seems that CLK_IN is LVDS_CLK/bits
18:56
dmj_nova
so it's probably something like "pixel clock"
18:56
dmj_nova
or "word clock"
19:39
se6astian
I just added a cooling proposal to the google doc
19:50
Bertl
feel free to add the picture I drawed for illustration
19:51
Bertl
s/I drawed/I've drawn/
19:53
se6astian
done
19:53
se6astian
what do you think of the copper pipes?
19:54
Bertl
heat pipes work (if they are heat pipes) just copper won't work
19:55
Bertl
but I doubt that we will have the space for this config
19:55
se6astian
btw in your concept, where/how would the FPGA be getting the data from the image sensor
19:55
Bertl
you see the brown blocks? those are interconnects
19:56
se6astian
ah sorry, its in the text, since they hold the pcbs in place I thought they were spacers
19:56
se6astian
http://www.ixbt.com/mainboard/asus/a8n32-sli-deluxe/board.jpg
19:56
se6astian
I always thought its copper
19:57
se6astian
but I guess its something else in the core of the pipes
19:57
Bertl
yes, it's something which evaporates at the higher end
19:57
Bertl
condenses and flows back on the other
19:58
Bertl
from the first look at the heat pipe rendering, the PCB normal to the senor seems to be twice as large as the sensor board
19:58
Bertl
that means, that the frontend will be roughly 140mm long, yes?
19:59
Bertl
one potential problem we can have there is the assymetrical arrangement of the interconnection with the sensor
20:00
Bertl
i.e. vastly different lane/wire lengths
20:00
se6astian
yes, i see
20:00
se6astian
I placed the PCB mainly because the SSDs have their SATA interfaces at the backs and need to plug in to somewhere
20:00
se6astian
with the sandwich PCB the lane length can be symmetrical
20:01
se6astian
maybe 3 PCBs then? 2 in sandwich and one for external interfaces?
20:01
se6astian
external interfaces and power supply ...?
20:01
Bertl
for the sata part, I wouldn worry about the orientation
20:02
Bertl
there are right angle sata as well as straight ones
20:02
Bertl
and the disks could also plug in from behind, which IMHO would be a better design anyway, as they are 'optional'
20:02
Bertl
so the disks wouldn't use up space when not equipped
20:03
Bertl
(might even allow for larger/cheaper SSDs)
20:05
se6astian
I want to keep the backplate free so any sized battery adapters can be attached
20:05
Bertl
okay
20:05
se6astian
these sony batteries are rather small and look like the free space is wasted but other adapters might use the entire area
20:06
Bertl
maybe we can have a riser-card concept?
20:06
se6astian
btw Konstantin had the idea to use water cooling a long time ago
20:06
se6astian
with this as pump
20:06
se6astian
http://www.murata.com/products/micromechatronics/demonstration/microblower/index.html
20:07
Bertl
doesn't help if you cannot dissipate the heat :)
20:07
se6astian
no, but water pipes are rather flexible
20:08
Bertl
and rather messy :)
20:08
se6astian
which is especially an advantage if you want to calibrate the sensor alignment on 2 axis
20:08
Bertl
I always wondered why you would want to do that
20:09
Bertl
not the calibration, but moving/tilting the sensor not the lens mount
20:09
Bertl
IHMO it would be way better (from the mechanical and electrical PoV) if you adjust the lens mount not the sensor
20:09
se6astian
we can also tilt the lens mount, I thought moving the smaller lighter side would always be easier :)
20:10
Bertl
well, let's make a pro/con list
20:10
Bertl
titling the sensor means:
20:10
Bertl
~ 250 connections need to be flexible
20:10
Bertl
- cooling needs to be flexible
20:11
Bertl
tilting the lens mount means:
20:11
Bertl
- some mechanical mechanism to allow for adjustments
20:13
Bertl
if the adjustments are only in two directions, it can be simply solved by a spherical joint
20:13
se6astian
its an interesting approach, but it needs to be designed in a very solid, robust way, the lens is the heaviest part of the entire camera and at the same time needs to be the most accurately placed part in the entire design
20:14
Bertl
i.e. basically a sphere sector directly touching another shere
20:15
Bertl
http://mathworld.wolfram.com/SphericalSegment.html
20:15
se6astian
we only need a few mm or a few degrees of freedom for calibration, maybe that would be quite simple to do....
20:16
Bertl
if you put two of them on eachother, and have slots for screwing them together
20:16
Bertl
note that they do not need to be very large to give good stability
20:16
se6astian
hmm I cant quite imagine how that would look like/work yet...
20:17
Bertl
get a ball/sphere, cut off the top
20:17
Bertl
cut out the sensor in the circle you get from cutting the spehere
20:18
Bertl
now take the lens mount and cut out a sphere (actually the same sphere)
20:18
Bertl
now you can place the lens mount on the spherical segment with the sensor
20:18
se6astian
yes but how to screw them together?
20:19
se6astian
since you dont know where the holes will end up?
20:19
Bertl
screws have to be perpendicular to the sphere
20:19
Bertl
but they can move inside a small slot
20:20
Bertl
I'll do a drawing if that helps
20:21
se6astian
yes please :)
20:21
se6astian
starting a movie now
20:22
se6astian
will check it out later then
21:29
aombk
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21:32
Bertl
welcome aombk!
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aombk
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aombk_
changed nick to: aombk
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aombk
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21:37
Bertl
se6astian: http://vserver.13thfloor.at/Stuff/AXIOM/lens_mount_tilt.stl
21:39
Bertl
note that this is illustrative only, i.e. to make it work you want to use the equatorial region i.e. the base has to be either larger with the lens/front inside or somewhat smallerwith the lens tube covering the sperical section almost completely
22:05
se6astian
thanks, I will check it out
22:09
se6astian
so the screws from the outside hold everything in place just by applying pressure?
22:09
Bertl
yep, works in both cases
22:10
Bertl
can be improved by some kind of rubber between the joints
22:10
Bertl
or something which adds a little grip
22:10
se6astian
but will that be enough to hold a lens that weighs several kilos?
22:10
se6astian
rubber would alter the FFD wouldnt it?
22:11
Bertl
FFD?
22:11
se6astian
flange - focal - distance
22:11
se6astian
http://en.wikipedia.org/wiki/Flange_focal_distance
22:12
Bertl
I'm talking about a fraction of a milimeter of thickness
22:12
se6astian
0.01mm accuracy is common for FFDs
22:12
se6astian
like 38.67 mm for four thirds
22:13
se6astian
thats why the lens mount has to be so precisely milled
22:13
Bertl
well, then just roughen up the joints a little
22:13
Bertl
can be done in the 10^-6m range
22:14
Bertl
will provide enough grip to keep it in position
22:14
Bertl
but it's just a concept, I haven't seen anything like this before
22:15
se6astian
I just want to make sure this will stay steady even with a heavy lens when shooting in a helicopter with strong vibrations...
22:15
Bertl
also, we could make the entire stack tiltable if the tilt is somewhere in the 0.01mm range
22:16
se6astian
maybe we can seal the position with screws from the other side as well? keeping the edges in place...
22:16
se6astian
anyway, going to bed, I will think more about it tomorrow and draw up something
22:16
se6astian
many thanks for thoughts and ideas, its exciting to do something a different way than anyone else before :)
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aombk
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