#apertus IRC Channel Logs

off for a nap ... bbl

:)

rexbron_: had a nap :) well, I got HDMI data output (not sensor data but memory data) almost finished, there seems to be a minor bug somewhere which I have to debug

nope, it is a zedboard

yes, that I could do, even with up to 500MHz :)

http://www.zedboard.org/sites/default/files/Avnet%20ZedBoard%20Brochure%20English%20Version.pdf

Cool

and it currently can do about 450-500Mbit/s (probably a driver issue)

the XC7Z030 ist the first in the zynq series to feature high speed serial ports

off to bed now ... have a good one everyone!

morning se6astian

se6astian: nope

se6astian: what changed on the meeting?

and I converted the time to more timezones

time to go to the supermarket

morning everyone!

just talking to konstantin

good :)

\o/

its a bit tricky to do an "open source" design

because the software to design such sensors is EXTREMELY expensive

even if you could call sharing that files "open source"

where you could easily have 20 layers or more

which costs around 50.000€

but there are many very expensive steps in such a process

it will cost you a shitload to use them

it could be documentation

also the final files that contain the layers are somewhat optimized for the machine they are used for already

what do you think?

explanation makes sense and confirms what I basically assumed ... i.e. an open hardware sensor doesn't make that much sense :)

hey troy_s_!

fine so far, thanks for asking! and you?

why not work on axiom then? :)

Bertl: How goes engineering land?

Bertl: Would love to see a shot of that IT8

(i.e. without proper illumination as you would call it)

(little like quartz, assuming not at edges of lifespan)

what I have is a simple light bulb as used for roomlighting (100W)

an 100 watt tungsten halogen should be around 3000

okay, then I'll prepare a shot

will take a little, I have to finish the current code/compile/test session first, but I should have something this evening

gotta pick up my girlfriend now, its her birthday ;)

hmm, new problem, the chart is _very_ reflective

Bertl: Are you bouncing the light?

that seems to work somewhat, but I probably need a second one to even it out

Bertl: you can use either a white sheet or a slightly opaque shower curtain to diffuse the light and reduce specular reflections. Not the most elegant thing, but this isn't a rigorus engineering test is it?

the chart is so specular that the background (table and so) is reflected :)

nice!

in particular, file system performance becomes an issue when a days footage, in our case about 1TB, was 400,000 files.

NTFS

well, who uses NTFS in serious work? :)

:P

we ended up going to tar archives, as those had much higher write performance at the expense of having to wait 10 min to open them back up

we also produced 30TB of raw files for 8 days of shooting (3 backups)

the trade off with uncompressed raw is storage. For a film with a 8k budget, we spent almost 1.5k on hard drives

Bertl: Part of that reflectance should be by design.

http://vserver.13thfloor.at/Stuff/AXIOM/RAW/IT8_incand.raw16.xz

Bertl: is that a compressed file or is xz some file format I've just never heard of?

yes, xz is just a compressor, more efficient than bz2

16 is 16 bit?

Bertl: lol, I'm going to need to figure out how to read this file

so 12 bit + 0 pads

yes, basically XXXXXXXXXXXX0000

Bertl: I take it it is stored in integer?

Bertl: whats the recomended workflow to open said raw file right now?

rexbron: load an oiio buffer?

rexbron: Export to EXR?

IIRC, rawtherapee was the recommended app by Aaton before it they went under

not sure if it is the most up to date

Bertl: So ideally going to float and transforming to primaries would be optimal.

rexbron: I think dumping the ints to OIIO then using OIIO to convert to floats is safest.

also for reference, DNGs genereally include two 3x3 matrixes to get from cameraRGB to XYZ under CIE A and CIE D65 (or D50 can't remember)

What CT is Illuminant A?

~2856 CCT

Grr.

troy_s_: that does represent the bottom end of most encountered incandencent sources

rexbron: Upside is that I guess we can calculate an almost native matrix using Bertl 's test. Lulz.

wb, send congratulations to your better half from me :)

rexbron: Most good ones are contextual. Tell me why incandescent for a camera?!?!

rexbron: Right... so tungsten 3200 for the past 100 odd years of cinema didn't exist.

idiocy

3200 was where their emultion worked best for tungsten stocks

rexbron: proper tungsten burns very close to that. a photographic certainly does.

open ended transform?

yes, thats what I concluded as well

but I suppose that's a bit like dedicated GPUs. For most purposes, the important thing for most isn't that they can built their own modified unit, it's that they can make it do new things

they even give you the full datasheet without an NDA

though, to be fair, if it were somehow possible to put the software in more hands, that might change the underlying design process

and we certainly don't have the developer power for that

design software for sensors

according to konstantin design software for sensors costs around 1 million dollars per license, there are like a handful of companies that are able to buy that software, using it is quite a science on its own

se6astian: no, I don't think so

*bitcoin

Cool

rexbron: That would permit arbitrary white balance (and even a color shift skew) as well as permit choice of transform etc. on how to get there.

see you!