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"Biggest" DOF w/Red1, Scarlet, GH1, & Canon ??


Bwana George

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I have a hypothetical question I'd like to throw out there and see what your opinions are. Just humor me and give me your advise and expertise in this area.

 

IF all these cameras, the RED-One, the Scarlet, the Panasonic GH1, and the Canon 5D Mark II, used EXACTLY THE SAME size/portion of the sensor, which one would produce the BEST quality image with the "biggest" Dept Of Field? Not the shallowest DOF, the "deepest".

 

In other words, if the larger sensors were cropped down to match those cameras with smaller sensors, so all sensor sizes were EQUAL, which of these cameras would produce the highest quality video with the WIDEST depth of field, and give the kind of quality usable for HD television production?

 

Everyone on these forums seems VERY concerned about getting a camera that will give them the shallowest DOF possible, but I'm interested in exactly the opposite. I want the deepest DOF I can get with the best quality 1080p HD video. The kind of specialty work we do requires it.

 

Thanks.

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I don't know why you had create 3 threads to ask this question.

 

Since it doesn't exist, the Scarlet is a difficult one to speak for, but in theory the Scarlet with a 3k Bayer on a 2/3 sensor.

 

Sorry about that. I was only trying to put it under different categories to reach a wider spectrum of people.

 

I realize the Scarlet does not exist, or may never exist. That's why I said my question was "hypothetical".

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If they all used the same sensor size and thus the same focal length lens for the same field of view, and were all shot at the same f-stop and at the same distance, then they would all be similar in terms of depth of field. At that point, you could argue that whichever had the softest image probably had the least critical focus and thus had a "deeper" depth of field but mathematically, they'd all be the same.

 

Since out of that list, the Scarlet 2/3" has the smallest sensor and every other camera would have to be cropped to match it, odds are high that the Scarlet would deliver the best-looking picture. The worst would be cropping a 1080P Canon 5D video recording in post to match the field of view of a 2/3" sensor area, that would end up worse than NTSC resolution. There is no way for the Canon to internally crop the sensor before conversion to 1080P, so you'd be doing it in post, and that's a 36x24mm sensor area you are talking about cropping to about 10mm in width, so you'd be only using less than 1/3 of the recorded 1080P image.

 

This seems a bit like a pointless question because no one would shoot a Canon 5D in video mode in this way, only wanting to use a 10mm width of the 36mm-wide sensor.

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I want the deepest DOF I can get with the best quality 1080p HD video. The kind of specialty work we do requires it.

 

If what you want is 1080p with a large depth of field why ask for the comparison of those cameras? - there are a number of low cost prosumer cameras that shoot 1080p and have a small sensor thus rendering a large depth of field relative to the frame size.

 

The panasonic AG-HMC40 camera has 1/4 inch chip and shoots 1080p. Also, unlike the scarlet, it exists.

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Bear in mind that going to smaller chips for more DOF runs you into the diffraction limit. For 2/3", it's f/8. For 1/3", it's f/4. At deeper stops, those cameras lose resolution to diffraction.

 

 

 

 

-- J.S.

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If they all used the same sensor size and thus the same focal length lens for the same field of view, and were all shot at the same f-stop and at the same distance, then they would all be similar in terms of depth of field. At that point, you could argue that whichever had the softest image probably had the least critical focus and thus had a "deeper" depth of field but mathematically, they'd all be the same.

 

Since out of that list, the Scarlet 2/3" has the smallest sensor and every other camera would have to be cropped to match it, odds are high that the Scarlet would deliver the best-looking picture. The worst would be cropping a 1080P Canon 5D video recording in post to match the field of view of a 2/3" sensor area, that would end up worse than NTSC resolution. There is no way for the Canon to internally crop the sensor before conversion to 1080P, so you'd be doing it in post, and that's a 36x24mm sensor area you are talking about cropping to about 10mm in width, so you'd be only using less than 1/3 of the recorded 1080P image.

 

This seems a bit like a pointless question because no one would shoot a Canon 5D in video mode in this way, only wanting to use a 10mm width of the 36mm-wide sensor.

 

It is NOT a pointless question, if everyone would please keep in mind that I said it was "hypothetical". Hy po the ti cal !!

 

There is no such thing as a "pointless" question. We are here to learn and to teach. NOTHING can be learned without a question in the first place.

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There is no such thing as a "pointless" question. We are here to learn and to teach. NOTHING can be learned without a question in the first place.

 

I think David answered your question quite succinctly. His 'pointless' statement referred to cropping a 5Ds sensor down to 2/3"

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It is NOT a pointless question, if everyone would please keep in mind that I said it was "hypothetical". Hy po the ti cal !!

 

There is no such thing as a "pointless" question. We are here to learn and to teach. NOTHING can be learned without a question in the first place.

 

 

Maybe I should have said it was an "impractical" question instead of "pointless" -- I only meant pointless in that it has no real-world application because you would never record HD video on a 5D and then crop it down by more than a third of its original image size just to get a 2/3" DOF effect, and I don't know of any other way in which to only use a 2/3" area of the Canon FF35 sensor for shooting motion.

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Maybe I should have said it was an "impractical" question instead of "pointless" -- I only meant pointless in that it has no real-world application because you would never record HD video on a 5D and then crop it down by more than a third of its original image size just to get a 2/3" DOF effect, and I don't know of any other way in which to only use a 2/3" area of the Canon FF35 sensor for shooting motion.

 

No problem David, and thanks. I understand what you're saying and I appreciate the feedback.

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  • 2 weeks later...

I responded over in the canon forum before I saw the same post here. I'm kinda psyched that my guess was somewhat in line with David's more educated response!

 

As I was thinking about it I did also think for a second that it was, not pointless per se, but perhaps mis-phrased as far as achieving the deepest DOF. Because you threw the 5D in there, it becomes more of an academic puzzle about whether a bigger sensor produces a 1-1 bigger image in the footage (which it does not in the case of the 5D). It was a fun question to ponder, though, I suspected this was not what you were wanting to know.

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