High Definition with Elphel model 333 camera

[Wayne Morellini]

I understand.

[Jose A. Garcia]

I've got a question... What would be the minimum specs for a computer to control the Elphel if you want to get 2048x858 pixels @24fps fixed?

[Oscar Spierenburg]

Here are some more of my thoughts on real-time preview during shooting.
From my experience with the 333 camera hooked up to a laptop, I'd say this: You would think you like to have all the controls you can think of (from exposure to color controls etc), but when you are actually shooting, especially outdoors, you'd prefer some basic presets with minimal control over exposure time. Another thing is... you don't see anything on most lcd screens in bright sunlight. So you don't have more benefits from digital preview than an optical one.
Right now, the ajax interface provides a full res. preview which updates about once a second. This is absolutely fine if you want to set you're exposure and color adjustments. You'd know exactly what your footage is going to look like and you can't adjust anything while shooting anyway.
EDIT:(excuse me if I have repeated myself, I'm just thinking out loud, making clear priorities for this project)

So to add to Jose's question, if we are looking for a small portable controller for the Elphel 353, what would be the minimal specs, when you only need what I described above.

Originally Posted by Steven Mingam

A nokia N800 ? it's an "internet tablet" but with wifi only (so you need a ethernet>wifi adaptor, does that exist ?). I read about a guy controlling is Nikon with it for auto-bracketing without moving the camera (HDR shooting).
The screen resolution is quite nice (800x480) and it's running linux so you can hack it at will.

Would something like this be suitable? Does someone has more thoughts on this one?

[Daniel Lipats]

The last few weekends I have been shooting some short films with the my old integrated 333 design, it works pretty well and is helping me plan the next revision.

I have been building a Linux distribution that runs form the hard drive and is optimized for filmmaking with the 333. The boot time is pretty quick, much better then the cd. I'm also coding custom software that shows a real time preview while recording and provide other camera controls. Once the interface loads the camera is automatically configured to my filming presets. Most of it is working already, just needs some optimization.

My goal is to make the camera boot right up and to record at the hit of a single button. No messing with any other software or typing in numbers. I bought an avr board and some other hardware to put together an analog interface to the camera settings.

As for the rest of the hardware, I was able to find a good micro atx board which will make the camera a much smaller integrated package. The next camera body will be fiberglass, stronger and lighter.

[Serge Victorovich]

Originally Posted by Wayne Morellini

Yes, I agree, visually lossless is good enough, but with Bayer, lossless would be preferable because of the knock on effects of color deviation during de-bayering. Otherwise, I think lossless is only of much use in movies for green screening, and computer graphics, even though I find it more pleasurable to look at than visually lossless.

Is anybody working on the choice of down converting 4:4:4 binned pixels to Bayer pixels before compression, to reduce compression and data rate?

Will the Dirac wavelet FPGA project be of any good to you, or is there any other wavelet FPGA codecs out there (2D-5D)?

Pete Bleackley do implementation the Dirac Open Source video codec in VHDL.
His work in progress can be seen on Opencores.

A 3 years ago David Newman (Cineform CTO) and Rob Scott discussed about Dirac codec and wavelets compression :) http://www.dvinfo.net/conf/archive/i...25808-p-2.html

Just "Groundhog Day" :)

[Oscar Spierenburg]

Originally Posted by Daniel Lipats

The last few weekends I have been shooting some short films with the my old integrated 333 design, it works pretty well and is helping me plan the next revision.

I have been building a Linux distribution that runs form the hard drive and is optimized for filmmaking with the 333.
My goal is to make the camera boot right up and to record at the hit of a single button.

That's all good news Daniel. I've also spoken to Alexandre Poltorak from Elphel who is working on an Ubuntu based distribution which also installs to the hard drive. This is all very crucial to make the Elphel a very usable cinema camera.
It's just bad luck I had no time at all to spend on the project these last months, but that'll change.
I am working on improvements on my optical parts (35mm adapter, macrolens etc) while waiting for some better power supplier for the 353. (Anyone got a good idea on how to make 48v DC portable. Can I make some sort of voltage quadrupler(?) on a 12v battery? )

[Take Vos]

Originally Posted by Oscar Spier

(Anyone got a good idea on how to make 48v DC portable. Can I make some sort of voltage quadrupler(?) on a 12v battery? )

They are called "DC-DC converters" you can find them at places like www.rs-online-com

Cheers,
Take

[Thomas Kumlehn]

With the harddrive option in view and the sensor-switch option, how about a system that alternately captures and compresses a left and right eye Micron sensor image with a camera body similar to this:
http://www.3dworld.cn/show_product_detail_en.asp?id=65

[Matteo Pozzi]

Hi to all :-)
I've got an Idea to increase the dynamic range of the mjpeg output of the elphel (maybe Andrey can tell me if it is possible or not! ).
the jpg format is only 8bit depth for that reason we all want a raw capture ...to save more data that come from the sensor. so this is only a software trick ;-)
I've read http://www.hdrsoft.com/resources/dri.html and here is my idea:set
the camera to shoot at 1/48 sec and the first frame is overexposed the second normal exposed (a sort of bracketing mode of digital camera) 3° frame over 4°normal...and so on ...the elphel hardwere now take every couple of frame and blend in one jpg frame like what software like Photomatix of photoshop cs2 does
see example: http://www.hdrsoft.com/examples.html
and in the camera control insert a flag for hdr imaging with a slide option for "Strength" to controls how much of the HDR effect is applied.
the output will be a 1/24 sec movie file with more dynamic range and more motion blur
what do you think!?!

[Les Dit]

Won't work if the image is moving. Works great for still pictures.
You are right, 8 bits is very limiting for color correcting.
With all due respect, might as well get a canon HD camcorder and shoot 1440 x 1080 HD video for $950 ? But I do think it is fun playing with home brew alternatives. Making it 10 bits would really make it worthwhile, and better than the $950 camcorders. Before long, the consumer camcorders will shoot 10 bits, I predict. Elphel guys better be planning ;)
-Les

Originally Posted by Matteo Pozzi

Hi to all :-)
I've got an Idea to increase the dynamic range of the mjpeg output of the elphel (maybe Andrey can tell me if it is possible or not! ).
the jpg format is only 8bit depth for that reason we all want a raw capture ...to save more data that come from the sensor. so this is only a software trick ;-)
I've read http://www.hdrsoft.com/resources/dri.html and here is my idea:set
the camera to shoot at 1/48 sec and the first frame is overexposed the second normal exposed (a sort of bracketing mode of digital camera) 3° frame over 4°normal...and so on ...the elphel hardwere now take every couple of frame and blend in one jpg frame like what software like Photomatix of photoshop cs2 does
see example: http://www.hdrsoft.com/examples.html
and in the camera control insert a flag for hdr imaging with a slide option for "Strength" to controls how much of the HDR effect is applied.
the output will be a 1/24 sec movie file with more dynamic range and more motion blur
what do you think!?!

[Jose A. Garcia]

I was going to say exactly the same. If you shoot an image 1/48 of a second and then another one and blend them together, you get a double image, not more motion blur. In fact with 1/48 you get the exact amount of motion blur you have with standard film. That "extra" motion blur is useless.

The only way to get more color info on the image is shooting lossless. You still have 8bit but something more similar to 4:2:2 in terms of color compression instead of 4:2:0.

Is the Elphel better than shooting with a HDV prosumer camera? IMHO yes.

Why? Well, just think about all different stretching and sharpening processes you get when shooting HDV and the fact that you're also compressing the image after all that. Let's say you're shooting something you want to look more cinematic, so you turn on the famous "frame mode". Now, the sensor captures 50 fields per second (1440x540 active pixels each). As you're in frame mode, each other field gets deleted. That 1440x540 image is then stretched to 1920x1080 and sharpened. After all that it gets interlaced again so it can be compressed in HDV and seen in non-progresive equipment.

That's what you get when shooting something you want to look like film with something that was designed to maximize compatibility with old TVs and standard non-progresive stuff.

Now with the Elphel and all different real progresive cams (like SI2k and RED) every single pixel you capture is where it has to be. You can capture a 2048x858 image and the sensor really uses all those pixels, appart from the fact that you're actually shooting progresive, just like a film camera does. Of course those cams are not perfect. You still have problems with rolling shutter and you end up compressing the image anyway but again, IMHO, the image and motion feeling you get is way better than shooting HDV.

[Jose A. Garcia]

Just in case someone points it out, yes. With the HV20 you get better image quality than other HDV cams, but I think the Elphel still beats it in terms of cinematic feeling, appart from the fact that you can actually shoot 2K with the Elphel (2.39:1).

[Les Dit]

Perhaps there should be a little footage 'shoot out' to compare against a HV20 with the proper de-interlacing done. It's fun to talk about all the image processing steps involved in the HDV cameras, but the end result is what really matters, isn't it?

Here is a practical question: Where can I download some sample Elphel HD footage from, to start ? Surly there is an active link somewhere !
-Les

Originally Posted by Jose A. Garcia

Just in case someone points it out, yes. With the HV20 you get better image quality than other HDV cams, but I think the Elphel still beats it in terms of cinematic feeling, appart from the fact that you can actually shoot 2K with the Elphel (2.39:1).

[Serge Victorovich]

Originally Posted by Les Dit

Here is a practical question: Where can I download some sample Elphel HD footage from, to start ? Surly there is an active link somewhere !
-Les

HD cinema camera Development FAQ (Matteo Pozzi)

You can download the (54MB) file here: http://community.elphel.com/videos/RomainSurMeuse2.avi (it's in Xvid compression)"

or the full resolution version Xvid (200MB): http://community.elphel.com/videos/RomainFULL.avi

[Jose A. Garcia]

My 353 is at your disposal, as soon as I buy it. Have in mind that I'm talking about cinematic image quality and motion feeling here.