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-   -   Rai & Markus' "Drake" HD camera (https://www.dvinfo.net/forum/alternative-imaging-methods/34339-rai-markus-drake-hd-camera.html)

Markus Rupprecht October 28th, 2004 12:10 PM

Re: ocillating adapter
 
<<<-- Originally posted by Richard Mellor : thank you for the footage markus: question - are you using a35 mm adapter type device. with rai's help and original drawings we are working hard on the ocillating adapter prototype. -->>>

Rai build already an oscillating adapter that has the quality of the P&S adapter. But we found a better optical solution for the DOF problem without a ground glas. Part of it is really to understand the workflow to handle lenses and the light in a scene in a way that allows shots like the one you have seen. Focus pulling, for example is even more important when you open up the aparture. That's what you need to do, to compensate a smaller focal plane and / or smaller distance to the object.

You all know the physics behind the DOF, so I don't need to explain. Thing is, it's not only engeneer thoughts that led to our development It's pretty much cameraman experience and engeneer skills. We startet our quest by searching and buying the best ground glasses available.

But even with the best setups we lost 2 f-stops through all the extra glas. Plus, when you move the GG you loose sharpnes on a subpixel level. Now, 2 f-stops means you need 4 times more light in a scene. Imagine a night scene at a campfire. 4 times more light - there's a difference. And what good is it when you build a relativly cheap ground glas adapter just to end up attaching SLR lenses worth thousands of $? Plus the expensive light you need for your scenes? Browse through your camera bags. How many sharp lensen do you own that are as fast as 1.4 or better: 1.2? 50mm... big deal. But any wide angle among them? Any 20mm? 28mm? 80mm, any 135mm? That would be a set of lenses you could work with. Try to find a fast set of those and you rethink everything.

That's why we concentrated on developing a workflow that allows the camera operator to control critial DOF situations you get when you open up the aparture. That means you need to see your picture in full detail all the time (realtime preview with no lag in full resolution for one thing) and you need fine and total control over the Lens position (3 axis moving and panning head) and a intelligent focus device, helping the operator to pull focus as easy as possible.

Combine that together with the fastest lenses you can get and you can skip the ground glas thing entirely and expensive law suits with the P&S or the movietube guys.

Brett Erskine October 28th, 2004 07:34 PM

Markus-
Are you getting exactly the same level of DOF as with 35mm out of your camera? If so how? What size is your CCD? You mentioned that you were using a fixed 25mm lens from a 2/3" camera. Yor lens had a great f/stop of 0.95. Is this how your getting your DOF? Seems like a pretty rare lens. Were you able to find any other lens to complete a full set (zoom or fixed) that had similar stops and if so what were they and how much did they cost? The reason why I ask is even 2/3" shooters are looking for better DOF then what their cameras traditionally offer them and are able to get it with the pro version of the Mini35 adapter - the Pro35. How does your results compare DOF wise?

Ben Syverson October 28th, 2004 11:34 PM

Jason wrote: "I do not know of any 2/3" lenses from Angenieux, Zeiss, Optima, Cooke, etc. that open up that wide. (f0.95)"

There are actually TONS of 25mm C-mount f0.95 lenses. Google them. Remember that that's not T0.95, it's f0.95... I have an Angeniuex 25mm 0.95 sitting right here, and it's what I used to shoot a lot of the tests on the Sumix camera.

Speaking of the Sumix camera, the stills that Markus and Rai posted look exactly like the output of my IBIS-5. Coupled with the fact that they say it's a 2/3" sensor, it's not very sensitive, and it's inexpensive, the only sensor it COULD be is an IBIS-5. If I'm wrong, please correct me.

Furthermore, it looks like they're using essentially the same algorithm as me for de-bayering. Perhaps it's even my software? The de-zippering process is what leads to the "grid" pattern that people have commented on. As Markus mentioned, you have to recalibrate the DAC offsets for both greens for every gamma adjustment, or else you'll get extensive gridding. Looks like they figured that one out the hard way...

All in all, this is absolutely nothing new as far as I'm concerned -- I was doing this months ago. I'm just waiting for the Altasens to hit...

- ben

Ben Syverson October 28th, 2004 11:43 PM

Brett asked "Were you able to find any other lens to complete a full set (zoom or fixed) that had similar stops and if so what were they and how much did they cost?"

When you deal with a 2/3" sensor, you're basically dealing with the same area as 16mm film. So your best bet is to find good 16mm C-mount lenses. Video lenses will have better stops, but they aren't as nice.

I have a "megapixel rated" 8mm f1.4 Computar lens designed for factory automation, but my 10mm f1.8 Cinegon designed for 16mm cleans its clock any day.

The 25mm f0.95 is crazy -- nothing beats having to stop DOWN to get to f1.4. :) However, you can't really get a whole family of f0.95 lenses; the 25mm is that fast precisely because it's that size. As I understand it:
entrance pupil = effective focal length / aperture

So a 50mm lens with entrance diameter of 50mm will be f1.0, a 25mm lens with a diameter of 25mm will be f1.0. (At least in pure theory, and without any other glass elements...) The problem is that those two lenses will cover very different areas -- the 25mm wouldn't cover 35mm, for example, while the 50mm would. There's some interesting resources around the web about super-fast lenses. Check these babies out. Stanley Kubrick famously used a Zeiss f0.7 lens (designed for NASA) on "Barry Lyndon" to shoot film in candlelight (back before 500asa film).

- ben

Markus Rupprecht October 29th, 2004 01:55 AM

>> the only sensor it COULD be is an IBIS-5. If I'm wrong, please correct me.

It's IBIS-5A. But you're right. When you get into the topic, in the end there is really not much choice.

>> Furthermore, it looks like they're using essentially the
>> same algorithm as me for de-bayering. Perhaps it's
>> even my software?

Just a second here. So you wrote a software to debayer the images. That's absolutely neccessary, nothing new, you are right. And it's not your software. I don't know who you are and what kind of software you write but accusing someone willing to share experiences to a community right away to illilagaly having used intellectualy property is a good example why it's a better way to not diskuss every single step you do in a development in a public forum.

Yo may edit your post and remove this sentence.

Now. Did I miss any official competition here? On who is the center of the indie HD world? As I see it, as many approaches we have, as many camera concepts we will build. Ours is build to shoot feature films and that is exactly what we started. I'd say this is something new. I don't know of another project doing this. If so, please contribute the information. It would be of great help to share experiences We have one year of hard shooting labour ahead of us and we also discussed the possibility of going for another sensor (Altasens if available). The camera and software is build that way to allow it. But thing is. Today, Friday 29. october 2004 there is no Altasens you can buy in a store. Tomorrow we continue shooting. So we take what we have. And we are willing to share our experiences. If you feel the need to argue, please mail me in private: markus@drachenfeder.com

Barend Onneweer October 29th, 2004 02:11 AM

Hold on Markus... You're jumping to conclusions here. Ben has been on these boards for a while, and just for the purpose of pushing these developments he bought a camera, and experimented with some debayering tools that run within After Effects. He made the beta-versions available to the board, so it doesn't look like he's accusing anyone of anything.

He's merely pointing out that what you have been sharing with the board isn't really all that much...

And if you read these threads, you'll find that there's actually a couple of people working on developing a CMOS camera for feature production. I don't think many of us here are thinking of going newgathering with it...

Bar3nd

Soeren Mueller October 29th, 2004 02:22 AM

Hmmm... so it's IBIS5?! That means it's "just" 1280 x 1024 effective pixel res in b/w ... and because of the bayer color filter it's effective resolution is reduced even further. :-/
And of course it's still 2/3" (same as the Altasens) - so without an 35mm "adapter" you still have the same DOF basically as with almost any ENG cam...
The only real benefit I can see here is that you can record uncompressed/raw and have more control over the image (colorwise etc.) ...

Rai Orz October 29th, 2004 02:32 AM

Thank you Markus,

you say it: You and your crew will continue shoot with this camera. We will do a lot of things together, but the point is: This camera work.

Ben, yes it is a IBIS5A (not IBIS5), but it is not a SUMIX, not USB2.0 or Cameralink, and it work with global shutter, and have a quarz clock for exacly 24fps, so there is no audio time shift. And there are some other special features.

Details you will found on a new webside.

Rai Orz October 29th, 2004 02:51 AM

Soeren,
yes, and no...

I am not the man who write the software, but i know, you can select a lot of debayer codecs on the fly. But its just for the viewfinder. We write the RAW data to disk and thats why you can select also different debayer codecs in the post.

We have more control over the image, because our camera head have a different hardware inside. You must know, the Sumix have a color problem at high speed, because the SUMIX use the A/D unit on the IBIS5 Chip. But our hardware use a external A/D unit with some other nice features.

But we build the other hardware not only for this IBIS5A. We work on a solution with a real full size 35mm CMOS sensor and 1024p. But this is another story.

Soeren Mueller October 29th, 2004 03:04 AM

Sounds interesting Rai! :-)
One more question: how do you capture the raw data? It's written to HDDs afaik... is this an extra unit (including a mini pc)? And how do you power it?!
Thanks! I'm curious as anyone else here is I guess...

Markus Rupprecht October 29th, 2004 03:37 AM

@soeren

we are getting there. Let me write my articles. We explain what problems we faced and how we solved them. As I said, the camera is mobile. It's a box that runs with batteries. Just be patient. I don't have much spare time right now. Besides: if you still got connections to this HD cinema we should think about a little test screening...

Soeren Mueller October 29th, 2004 05:37 AM

Markus, of course I understand that you're in the middle of shooting right now etc. and don't have much time on your hands - I sent you an email just a few days ago (and the rest of your team). Currently I have quite some spare time (thankfully ;o) again and also could help out with things like software dev. etc. (if help is still needed) and/or would like to visit your shoot (if you're ok with that) - and have a first hand peak at the cam :-) ... and of course the test screening would be an option too! (and I still got my own 720p projector ;o)
So don't hesitate to contact me!

PS: I already guessed it should be portable.. with "only" 720p (and 8bit as you said sometime) and perhaps losless compression the datarate should be managable with something that still remains portable. However with "real" HD (i.e. 1080p or even more) this should become more of a problem...

Rai Orz October 30th, 2004 01:55 AM

Yes, Markus shoot with IBIS5A. But not IBIS5 and not with Sumix.

Have you ever see a video like this:

http://www.drachenfeder.com/int/take1.avi
i think, next week Markus will send more

Show me a altasens clip. Show me a working camera with altasens. Okay, you can wait till the year nnnn. But all we wanted was a working camera NOW!!! And it work.

I say it again: There are worlds between Sumix and our Camera hardware. Sumix use a bad A/D, this produced dark pictures and bad colors and can not handle global shutter. We know this, because we tested also the Sumix camera (And others and others and others).

We found a german manufacter and developed together some special details for film making. And one of the next steps will be real big sensors.

The other side ist IBIS5A and DOF. We go a new way. We use ultra fast lesens to produce DOF near 35mm. You must know, with ultra better F-stops you have the same like bigger sensor sizes. DOF use F-stops not T-stops. But this part is optical engeneering and here is not the place for this.

At last. We build a camera design. Case, case-parts and also a software design.
For the big DOF sensitive, we build follow focus systems and more. We working on the web side. You will found all details there.

Barend Onneweer October 30th, 2004 04:23 AM

Hi Rai,

Definitely impressive footage, especially considering that this is just the start. And you seem to have a team that knows what they're doing and have a firm grasp on what it takes to develop all these pieces into a usable tool.

Which leads to the next question: do you have plans to sell these camera's in the near future? I think many of us would e interested...

Barend

Rai Orz October 30th, 2004 05:28 AM

<<<-- Originally posted by Barend Onneweer :
... the next question: do you have plans to sell these camera's in the near future? I think many of us would e interested... -->>>

Its not only my company, but i can say yes. And i add a quotation from Markus: "...be shure, we did it indie style..."


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