Rai & Markus' "Drake" HD camera

[Emanuel Costa]

Originally Posted by Alexander Kitaev

Hi ALL,
(...)You may ask me Yourself-))),
about camera status: this week we’ll have new body case,
and start testing new demosaic soft, with linear we have a lot of artifacts and focusing problems.
(as You may see on our pictures-))))
I think in two days we’ll be ready with new pictures(...)

When? I'm very interested in your camera but I'd like to see a regular up-date of your web site in ENGLISH, please! Because I'm interesting in a real purchase.

[Emanuel Costa]

Hey Drake folks! I've been following this thread - it's your thread, remember? - since January and now you're... How is it possible? So much work and NOT EVEN A WORD here?!...or in your web site. It's a weak point, indeed!

I was interested in a purchase of your camera - and maybe yet. It depends on you! As we know, there are several silent guys following your camera announcement. But this silence - a word will be enough - is more a liability than an asset... C'mon guys!

[Omar Saad]

Hi Levan, have you gotten the camera? How is it, what are your impressions. Any clips to post?


@ Alexander. Any clips posted yet on the site? Cant wait to see some.

thanks,
Omar

[Frank Schoerner]

Originally Posted by Alexander Kitaev

Hi ALL,
first- about sensor, it has 4M, 16x12mm, 6,9pixel, 2400x1700 it’s CUSTOM sensor, real 10bit,
max speed –1GB/sec- it’s about 350fps on HD resolution, or ~800 on SD
it’s first use in space, but now we try to make cinecamera…
(our next one will be with 12M resolution, 12-14 bits, but 2-3 years later…)
about other sensors- we tested ALL of them- all have motion bugs on rolling shutter (if it has speed less then 120fps) or problems with noise or sensitive.

Somethings right, others wrong...
Custom Sensors cost min. 500tsd USD. With those budget the case (and web side) design would be better, so i do some research, also on dvinfo, and now i am shure that the sensor is not custom design. It is a very old sensor, first for space, yes, but now you can find it in some camera heads (most with less frame rate, because most use only camera link). Do a google search for "PB-MV40" or "micron" + "MV40".

So this camera will never build with 12Bit.

[Levan Bakhia]

Can someone tell me some info about rolling vs global shutter.

I mean, I understand difference in terms of how it works. but in final picture how is rolling shutter inferior to global shutter.

Is it true to say that when rolling shutter has a higher fps it is same as global shutter?

(I know there will be a question about it, so here is an answer: I am expecting camera next week, and I will share the experience, and you would guess that this question is because the camera has a rolling shutter)


So waiting for your feedback.

[Frank Schoerner]

Originally Posted by Levan Bakhia

Can someone tell me some info about rolling vs global shutter.

rolling shutter at high speed is the same like global shutter at low speed. I saw pictures from global and rolling shutter cameras, all at same variable speed. At 120 or more fps i so no differents. At lower fps... igit... You need extrem short exposure time (the same like at 120fps), otherwise the clips "shake" at all side by side motions. So at the end i can say with rolling shutter it is impossible to get movie-like motion blur, because you allways need high speed shutter.

PS: I had a meeting with one frome the drake team (Rai Orz). Yes, the team is split of. I understand now whats going on. But Rai found new (bigger) partners and i heard (and also saw) very, very interesting news. Mutch more than only the old drake camera.

[Wayne Morellini]

Frank,

What is happening? How is Rai going, can we expect anything soon, and what happened to the other team?

Thanks

Wayne.

[Keith Wakeham]

Wayne, what other team do you mean exactly. Ctt.ru ??? or someone else that i'm unfortunately forgetting.

[Wayne Morellini]

Only the two split Drake teams, the other one being the one without Rai.

[Levan Bakhia]

First of all, when the team where Rai is going to present something if you know? I am very interested. Why don't they post here?

Second Question:

You say that with rolling shutter over 120fps, you get the same result as with global shutter, and then you also said that with rolling shutter you can never get film like motion blur. Does it not contradict? Please tell me in details, it is important for me now and I want to understand.

Thanks in advance.

On the other hand I will post some new clips with russian camera, and would seek everybody's opinions. :*)

[Keith Wakeham]

Levan,

All sensors read out 1 pixel at a time (depending on the number of outputs but normally 1) one line at a time. So no matter what type of sensor you have it reads out this way.

On a sensor of any type a shutter means to reset either a line or the entire array, essentially wiping all charge so you start with a black "image" and the photosite accumlate charge to create your image.

When you read out a line in any type of sensor the charge is lost, but their is residual charge that can add a lot of noise very quickly so the pixels have to be reset. This resetting is the shutter. Rolling shutter does this one line at a time several lines behind the line being read out. While Global shutter resets the entire array in one pulse.

So with rolling shutter when you read out the top line of the sensor it will be an entire frame away (so 24fps, it will be 1/24th of a second) from the bottom line. So that action that took place on the top line occured almost an entire frame before the corrosponding one on the bottom.

You should search for some pictures. The HC1 camera actually presents this artifact and you can see it on some sites and I think it was posted here once.
http://www.sonyhdvinfo.com/showthread.php?t=2688

The club in the picture shows how things distort with the rolling shutter. Once its in video its harder to notice since the top line corrosponds to the bottom of the previous frame but still pictures show it badly.

[Kurt August]

Ah! Thank you, Keith. Interesting as engineering can be (when it's explained clearly), I love this kind of posts. 'That's right,' answer many others.

I too want to give three cheers for you website.

[Levan Bakhia]

Great post. I understand it now clearly. and I understand why at higher shutter speeds, rolling shutter becomes close to global.

[Wayne Morellini]

Keith, is there any sensor that has on sensor memory to parallel readout the sensor outputs at one time, or make for very fast rolling shutter?

[Keith Wakeham]

Wayne,

Dont' quite know if I understand what you mean.

Do you mean store the charge that was built up somewhere else while the sensor gathers more charge. This is how an IT or FT CCD works.

Or do you mean like read out every line simultaneously. This would be a really big problem. Lines x bits = really big number of pins.

Could you clarifiy what you mean a little more? (It might make perfect sense but my brain is shuting down from writing final exams so not much is making sense right now)