Sumix 2/3" 1920x1080 CMOS

[Zack Birlew]

I saw a neat thing at Fry's Electronics today, it was a battery powered generator made by Xantrex.

http://www.xantrex.com/web/id/63/p/1/pt/10/product.asp

It was $300 if I remember correctly, could have been $400. But, if you needed outlets for your laptop/production LCD/lights/Sumix camera, this could be a nice thing to wheel around with you.

Also, the Ikan V8000T looked like a neat option for monitoring. Granted it is 4:3 but it's 1024x768 resolution and touch screen capability combined with the optional AA battery pack adapter to power it with AA batteries makes it a neat option for the Sumix camera. Heck, at the least it can be the control interface for your laptop or PC combo while you're recording.

I also looked at possible laptops to use with the camera, if you didn't want to go with a small PC setup. So far, I've looked at Sager notebooks. It looked to be the best bang for your buck I've found so far. One model I configured had a Geforce 8600GT graphics chip and comes in a variety of monitor size configurations with an Intel Core 2 Duo chip as the base up to 2.6ghz. A system using a 2.5ghz chip, Geforce 8600GT, 15" monitor, and 2gb of RAM with, granted a small by today's standards, 100gb 7200RPM hard drive came out to be around $1,424. Not bad as far as laptops go.

[Paul Curtis]

[QUOTE=Daniel Lipats;853093]Because of the relatively low signal noise level I believe saturation can be safely adjusted. Based on videos shot with SI-2K this camera should have a lot of potential.
QUOTE]

Daniel, im aware of this aspect of cmos vs CCD. I've been playing with various sensor heads a while now and the sumix is on my target list. And im hoping to get a general idea of how this one performs. Some cmos are just plain awful and after having it pointed out to me, then through actual testing, the red performance (no pun, just the colour red) is really problematic on cmos - perhaps as a factor of the sensors being daylight balanced and therefore you cannot actually push red as much as you'd like? I've had interesting results gell'ing the lenses for colour correction!

So far in very broad terms i've found colour more accurate on CCD by a long way. As you say though if cmos can be pushed further then fine. I have an EX as well and it is very sensitive but the fidelity breaks up very easily under low light. The EX also has a lot of compensation and highlight recovery going on -- it makes a nice image though. This is custom software that would need to be developed for a camera like this. But it may well be worth it. Sensor streaking on CCD is my pet hate!

The more pictures and images i see the better judgement i can make, i look forward to more!

cheers
paul

[Paul Curtis]

Originally Posted by Jose A. Garcia

I'm waiting for StreamPix or a new version of the Sumix software to see if the cam can give more light without burning highlights. I've seen SI2K tests and I think that's possible... or maybe the tests I've seen are Cineform RAW files corrected in post.

Jose,

Great stuff.

Part of the solution for highlight handling is good highlight recovery. This is for when one or two of the channels clip early. The recovery algorithm should reconstruct the highlight based on the information around to try and get around mis coloured highlights. (You can see pink highlights on those examples which is the blue and red channel clipping before the green)

You shot these images at f2? Outside? What exposure time or gain did you have or did you have ND on the lens?

You can push the image in photoshop to approximate the SLR version, you do very quickly blow the reds though and there's an overall red cast on it. So any post treatment needs more work than just pushing the saturation slider, some kind of LUT perhaps.

Are you getting a 12bit RAW out of the camera? Because obviously the movies are compressed 8 bit which isn't ideal for checking colours. Could we get a 16bit tif from a frame from this?

But it's pretty nice, certainly compared to a lot of other cmos. It has promise, that's for sure.

cheers
paul

[Samuel Hinterlang]

I got to playing around with the clips and fond that it mostly needed saturation on the high end but closer to black it was a bit more consistent. Towards white, you need to push the blue channel a bit more to bring everything back to center.

Every channel seemed to need its own special tweaking. Without working with the camera myself, I'd say you might be better off shooting what would seem to a bit too dark. Then just pull everything up.

I used a combination of curves and saturation adjustments here.
http://pghvideo.com/video/20mm_f2_cc.m2t

sorry it's HDV, Cineform's not in the budget.

(link will not last long, I don't need this sitting on the server)

[Jose A. Garcia]

Hi Paul,

I didn't know about highlight handling and recovery. I'll explain the color controls you have for the sumix so far, I guess these will change in future versions:

Basically you have an auto white balance which works just ok but it desaturates a bit, i.e. tends to turn the white surfaces gray.

Then you have brightness, contrast and gamma levels for full RGB and then separate controls for red, green and blue. Appart from that, you have frequency, exposure and gain levels.

I'm really interested in solving the highlights problem, because the camera performs just great and saturation can always be adjusted in post. Burnt highlights is the only problem I can see.

Yes, I shot this at f2 (you asked for f1.4, remember? but it was way too bright), of course setting exposure to very low levels and gain to 0.

The RAW 12bit option is not yet implemented, neither is 8bit lossless compression. So far you can just record using 8bit option.

Norpix... PLEASE!! Release the new StreamPix update!

[Jose A. Garcia]

Samuel, I find the red flowers oversaturated, I know you had to rise red levels a lot for the rest of the image to look right, but while the overall clip looks good, those flowers don't.

[Paul Curtis]

Originally Posted by Jose A. Garcia

Hi Paul,
I'm really interested in solving the highlights problem, because the camera performs just great and saturation can always be adjusted in post. Burnt highlights is the only problem I can see.

Jose,

Im surprised you managed to get f2 outside that's all!

Is exposure shutter speed? Or is that frequency? Im not sure what both of those would do. Gain is obvious. I would guess that some combination of those two created a very fast shutter speed letting you get that image without ND.

If you have separate controls over the RGB gamma some correction might be possible within that software but i think more sophisticated correction tools would be needed. You may find that the correction needed changes with exposure in which case you might be looking for various calibrated LUT tables.

Highlight recovery can be really very complex and it's probably best implemented in the debayer. Much like you have within Photoshop and various RAW convertors. There's a good explaination of what happens with dcraw somewhere online (i forget exactly where)

So the only recording is 8 bit compressed at the moment? No RAW files at all?

cheers
paul

[Jose A. Garcia]

No, 8bit uncompressed is the only option so far.

I'm sorry if the "remember?" thing sounded a bit harsh, it wasn't my intention.

I guess everything will change once we get to record using StreamPix or the new software from Sumix, from highlights to post color correction. We'll be able to do white balancing in post too. StreamPix allows framerate setting, doesn't it?

I think frequency is shutter speed. I was recording at 50Mhz which translates to 1/50 sec I believe.

[Daniel Lipats]

12 bit will work but you have to put the frequency to 36Mhz or less.

50Mhz and 12bit will turn to garbage. This may change with new software/updates.

[Paul Curtis]

Originally Posted by Jose A. Garcia

No, 8bit uncompressed is the only option so far.

I'm sorry if the "remember?" thing sounded a bit harsh, it wasn't my intention.

I guess everything will change once we get to record using StreamPix or the new software from Sumix, from highlights to post color correction. We'll be able to do white balancing in post too. StreamPix allows framerate setting, doesn't it?

I think frequency is shutter speed. I was recording at 50Mhz which translates to 1/50 sec I believe.

Luc might want to jump in here but streampix basically offers a UI against whatever the camera is able to do. so if the options are offered by sumix then yes.

the streampix workflow is creating and saving a sequence of say raw frames, then you can load that sequence back in and apply various plug-ins, like debayer and export in different file formats.

I believe so long as your set up can stream and dump out the data fast enough you can write to disc. Otherwise you can always record to RAM first (for testing mostly).

If frequence is shutter speed and gain is gain, what is exposure in this case?

Could it be the frequency is the read out frequency of the sensor and the exposure is the shutter speed? The aim is to have a high enough frequency to negate rolling shutting whilst still be able to control the shutter speed?

cheers
paul

[Régine Weinberg]

Dear Daniel
you wrote
...................................
12 bit will work but you have to put the frequency to 36Mhz or less.

50Mhz and 12bit will turn to garbage. This may change with new software/updates.
...................................
maybe stupid but which software, YOUR's or Norpix
may change is very vague.
If YES it could be some Pixels lower resolution
but who cares a real alternative and the only one to SI.
If you like to have big fanfares and applause
from the poor low budget indie film community
even outside USA PLEASE GO FOR IT
Gina

hm
white balance, knee and quite a long list
has to be done quite often, every scene you have
to do this as a question of light, inside outside etc.
If not on the camera body
on an attached Laptop
mini PC but not in Post please, would be a nightmare.

Everything ok on the scene frees the post
to do the work post is designed for

[Daniel Lipats]

There may be some kind of hardware bottleneck prohibiting 12 bit at 50Mhz. Hopefully thats not the case and is only a limitation/bug of the software. Farhad could clarify this for us.

If it is a bottleneck it may be possible to get around it by just shooting a bit wider, say 1920x800. Or by limiting framerate to 24p.

I will test this a bit later.

Shooting 36Mhz increases sensitivity giving a brighter picture, but also raises the chance of rolling shutter distortions. ERS is not horrible at 36Mhz, but it is there on fast pans. Very usable though, not much of a problem. Its just important to be aware of it.

[Régine Weinberg]

if it is no HW problem should be possible to fix. Sounds great to me
thanks. I blow my trumpet,..... you are dead fast.

[Daniel Lipats]

Just got the computer. Uploaded some scale and parts pictures:
(sorry, shot on a cell phone)
http://www.dreamstonestudios.com/per...12A2/computer/

I may be too optimistic, but I think there is room inside for 10Ah batteries, PoE and all other components.

Im going to try to draw power from the computers embedded PSU to power the LCD. I did this for my Elphel setup, just plugged the LCD directly into the 12V Molex connector on a PC PSU. I hope it has enough power.

I'm thinking about adding another fan to cool the case.

[Daniel Lipats]

I was thinking about using something like this for hot-swap hard drive cartridge. Have the main system run off solid state or just a 2.5" sata drive. Use the cartridge to record video.

http://www.newegg.com/Product/Produc...82E16817256030

The case has room inside if the front of it is cut. The 2.5" hard drives are contained in an enclosure with USB and eSATA.

If low on disk space just pull it out and replace with another cartridge. Or at the end of the day pull it out and transfer footage to workstation.

Sounds like a perfect solution.