RAW video and super 16mm glass?

Started by David J. Fulde, August 26, 2013, 03:15:55 AM

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David J. Fulde

So, I was wondering, whether it with crop-mode or with simply shooting at a resolution like 1280 or lower: Would it be possible to shoot using super 16mm glass? I know that PL-EOS adapters exist, and with RAW we can choose a specific resolution on the sensor so... Stands to reason that by croping down to 720 from 1080 (Or using crop mode and using a lower-ish resolution) we should be able to use super 16mm glass on, if not the 5D, something like the 50D

ItsMeLenny

Work out the difference between the canon crop sensor size and a super 16 "sensor" size, and you'll be able to find how much you would need to crop it by.
However, at the same time; the super 16 lens might have a wider fov that usually projects wider than the 16mm film, so you may not need to crop.
At the same time as that; depending what you use it might result in vignetting, which some normal canon lenses do as well, which when shooting not in raw canon has the option to enable correction for the lens, and also magic lantern offers settings for correction of the lens for manual lenses, but because you would be shooting in raw you would just use your favourite program to correct vignetting.

ItsMeLenny

I don't use this forum but it seems to be popular and they seem to have a similar post to what I explained (although I didn't read it I just looked at the pictures).
http://www.eoshd.com/content/10683/how-to-get-bargain-16mm-cine-lenses-for-the-upcoming-blackmagic-pocket-cinema-camera-and-digital-bolex

David J. Fulde

Let's see...

Super16mm is 11.66mmX6.15MM which is... 71.709mm of area

an APS-C sensor is 22.3mmX14.9MM which is... 332.27mm of area

71.709 * X = 332.27mm X is the crop factor

332.27/71.709=4.63

1920/2.32 = 827.59
1280/2.32 = 551.72

So, for almost to no vignetting, we need to shoot at ~828X552 resolution.

In other words: Not very much. (Granted, this can probably be blown up to 720P without too much issue) Crop Mode MAY work but I'm not sure what the math behind that would be, ha ha.

ItsMeLenny

It's probably something along the lines of that.
But also like I said, the lens probably projects wider than 16mm.
You'd have to try it to see what it actually does, and I'm curious in the results myself.
I've been planning to attach an 8mm lens to my dslr, but i cant get it off the box of the 8mm camera.
Also, some slight vignetting should be fine, because it's raw it can be corrected in post.
...I would hope :P

ItsMeLenny

And I also think your math is wrong.
Based on when I turn on raw video, the max res I can get is 1728x972 (in terms of setting not recording), and that takes up the entire screen, so it wouldn't be based on 1920x1080, this is from a 550D pov.
And additionally on top of that, 1080 would be the wrong height to measure from as you can use the whole 3:2 field.
Which also note, the project-able area of a lens does not change by width as it does my height, it projects a circle, so the same max res you can get of the width will be the same as the height. What makes a picture rectangle is either the sensor size or a gate blocking it, which is still part of the camera, not part of the lens.

Super16 = 7.41 mm by 12.52 mm = diagonal is ~14.54mm
ASP-C = 22.20 mm by 14.80 mm = diagonal is ~26.68mm
Diagonal is the widest projection of the image, this can be projected all around, as the projection is circle.
Basic trig states that the diagonal of a right angle triangle is: A^2 + B^2 = C^2

Super16 is a 1.835 crop of ASPC: (actually 1.834938102x)

The full frame of Raw mode (at least for 550D) is 1728x1152 at 3:2.
And again, the width of the project-able area of the lens will be the same as the height and will be the same as the diagonal.
Basing the crop from the width the raw res would be 940x940.
But when I think of that I think I have done it wrong because the diagonal is larger which means more pixels would surely fit...

Maybe I have stuffed up completely.

David J. Fulde

Hopefully later this month I'll be able to try it out with some of my local Film co-op's gear :) I will, obviously, post the results ha ha

EDIT: By later this month I mean Next month

robertgl

????

5DIII:
6.25 microns times 1920 = 12mm
6.25 microns versus 1080 = 6.75mm

50D
1920 = 8.832mm
1080 =4.96mm

S16 lenses should cover 1080P ezly, based on the pixel pitches

I've thought about getting the PL mount adapter and trying it out as well, but it's a lot of money to experiment.. i guess i can try holding them into the cavity of my 50D

David J. Fulde

with a 1:1 crop, yes. But I am wondering if I could shoot without the 1:1 crop hence why the mm are what we are meauring as that it where our image circle will lie.

robertgl

I have multiple S16 lenses and they only barely cover the corners of a S16 frame.. a 2x range extender should be able to cover APS C though. Anyway crop mode would be exactly why i'd use them.. should be better suited for the smaller sensor window size than full frame lenses

Nachelsoul

Even you got it mount it, you can't achive focus, you can only use it for macro work. The lens have to be VERY close to the sensor to get infinity focus.

ItsMeLenny

Quote from: Nachelsoul on August 28, 2013, 10:07:54 PM
Even you got it mount it, you can't achive focus, you can only use it for macro work. The lens have to be VERY close to the sensor to get infinity focus.

That's a very good point, much like the old canon fd lenses.
16mm lenses sat close to the film.
Unless one calculates a lens to sit behind the 16mm lens then yes, it'd only work for macro.

robertgl

The adapters on Ebay claim infinity focus. It ultimately depends on the  protusion of the rear element of whatever taking lens that you're using. They will vary

tihon

Quote from: Nachelsoul on August 28, 2013, 10:07:54 PM
Even you got it mount it, you can't achive focus, you can only use it for macro work. The lens have to be VERY close to the sensor to get infinity focus.

IT`s true! I have 16mm lenses and 550d. Can`t achieve a focus... Only for super mega macro)))) It`s time to drill the sensor hole)))
Cinema, cinema, cinema

Nachelsoul

Quote from: robertgl on September 08, 2013, 10:26:55 PM
The adapters on Ebay claim infinity focus. It ultimately depends on the  protusion of the rear element of whatever taking lens that you're using. They will vary
You are right. First I was thinking in C-mount as Super16 lenses, but there a lot of Super16mm lenses in PL mount. So if you want use them there is a PL adapter to do it, but you have to make room for the lens close to the sensor and also remove the mirror or lock it up in some way. So excuse me for what i stated earlier. now, super16 PL lenses on Eos cameras is possible. With Raw crop mode I think that the FF cameras suit better.