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Albert Smith

Black Magic Cinema Camera

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Alexander,

 

I looked at a 8mm Ultra 16 in projection. It is almost exactly the same image circle as the 9.5mm

 

The total is 16mm diameter and then it is a hard cutoff. I was going to put the picture up but it really looks identical. :)

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all ultra 16´s have the same diameter

 

 

 

Alexander,

 

I looked at a 8mm Ultra 16 in projection. It is almost exactly the same image circle as the 9.5mm

 

The total is 16mm diameter and then it is a hard cutoff. I was going to put the picture up but it really looks identical. :)

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I know I am a little late for this thread.

I do a ton of post work in the industry.

The 2k standard delivery is 2048x1152 - cropping the black magic footage to standard 2k workflows will likely allow the use of nearly all the super 16 glass out there.

 

Cropping into that 2.5k resolution for a 2048x1152 image is also a darn close match to the super 16 format when we are talking FOV of Super 16 objectives.

Using the Black Magic for shooting 2k would be very similar to the super 16 format, more so than 35mm objectives on the Black Magic.

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The 2k standard delivery is 2048x1152 - cropping the black magic footage to standard 2k workflows will likely allow the use of nearly all the super 16 glass out there.

Yes, but at a price. With bayer sensors, it's better to downres, to 2K rather than crop. But I've done crops, and they look awfully good.

 

Cheers.

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Yes, but at a price.

I agree somewhat, I love more resolution but you're not loosing resolution, resampling or scaling by cropping 2048x1152 from 2432x1366

I wouldn't say there is a price to pay, I would say its a workflow preference.

The format is closer to super 16mm than 35mm

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I agree somewhat, I love more resolution but you're not loosing resolution, resampling or scaling by cropping 2048x1152 from 2432x1366

You loose resolution by cropping. It may not be a great deal, but that is precisely why Canon, for example, is using a 4K sensor in the C300 to output only 1920x1080.

 

Remember, with the BM bayer sensor, there are only 1216 green pixels in a 2432 line.

 

In addition, one of the main reasons to try Super 16 lenses on the BMC is the lack of fast, ultrawide (~6mm, 8mm) lenses that match the small non-standard format. When you crop, the field of view narrows, so the advantage lessens.

 

I'm not saying it's not worth trying. Just that there is no free lunch.

 

Cheers.

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You loose resolution by cropping. It may not be a great deal, but that is precisely why Canon, for example, is using a 4K sensor in the C300 to output only 1920x1080.

 

Remember, with the BM bayer sensor, there are only 1216 green pixels in a 2432 line.

 

Sound like you might be confusing resolution with aspect ratio. You don't loose resolution when you crop, you loose resolution when you down sample the resolution.

If your image is 2048x1152 @ 72ppi and you crop it down to 960x540 you're still at 72ppi

What Canon did with the C300 has less to do with Bayer sensor issues and more to do with marketing and dollars.

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In addition, one of the main reasons to try Super 16 lenses on the BMC is the lack of fast, ultrawide (~6mm, 8mm) lenses that match the small non-standard format. When you crop, the field of view narrows, so the advantage lessens.

 

Cheers.

 

Take a look back at J Van Auken Diagram in his first posting on this thread. The black magic chip size cropped would be very close to super 16.

If you're used to shooting super 16 with super 16 glass cropping to 2048x1152 is closer to the FOV of super 16mm film making.

If the DP is used to shooting super 16 and calls for a 9.5mm lens its gonna be more accurate to his expectations or visual understanding of how wide that lens is if the footage from this camera is cropped to a more standard format like super 16.

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Sound like you might be confusing resolution with aspect ratio.

I'm not in the least bit confused.

 

If, as you claim, cropping preserves resolution, then a 720x486 (standard definition) crop would have the same resolution as the full sensor (high definition). So why even bother with the extra pixels, if you can magically turn SD into HD? By your logic, a 1x1 crop (yes that's 1 pixel) would have the same resolution as the full sensor.

 

All crops reduce resolution.

 

There is a very good reason all pro cameras oversample and downscale -- resolution.

 

Arri Alexa: "For ProRes recording and HD-SDI outputs a 2880 x 1620 pixel area is read from the sensor. This is then debayered and downscaled in camera by a factor of 1.5, leading to a beautiful 1920 x 1080 image."

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cropping preserves resolution, then a 720x486 (standard definition) crop would have the same resolution as the full sensor (high definition). So why even bother with the extra pixels, if you can magically turn SD into HD? By your logic, a 1x1 crop (yes that's 1 pixel) would have the same resolution as the full sensor.

 

You're definitely misunderstanding what I am saying, I must not be explaining it right.

The Resolution of an image is not determined by the pixel dimensions of the image, It's the measurement of information within those dimensions.

Yes if you did a 720x540 crop from 4k footage you have the same resolution from the senosor but you're using a smaller area of the captured image.

You are discarding part of the image but you're not loosing resolution.

 

It's a terminology thing many people confuse. The pixel dimensions of an image is not the resolution of an image.

The only way people usually "Loose Resolution" is to scale up an image or down sample the resolution.

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I think it would be interesting to test the blackmagic with super 16mm lens. Even with the crop its still going to be higher resolution then 1080x1920 bayer sensor in the Ikonoskop and that camera holds up pretty well on the big screen.

 

So it could be a good cheaper super 16 alternative to the Ikon.

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It's a terminology thing many people confuse. The pixel dimensions of an image is not the resolution of an image.

er...

 

Well, yes I get what you're saying - but you're not right in saying that pixel dimensions aren't the resolution of at image full stop - they well could be, but yes, not always ...

 

Noel, what neither of you are taking into account, or at least not communicating directly is the element of viewing distance - this is the missing part that should help make sense of the confusion. <div><br></div><div>Edit>>> Viewing distance as an analog of scaling ...</div>

Edited by Chris Millar

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but you're not right in saying that pixel dimensions aren't the resolution of at image

 

 

All I can tell you is research it. Image size is not resolution.

 

If you crop a 2k image (2048x1152) down to 720x540 you have not lost resolution you have resized the image by discarding part of the image and now have a tiny 720x540 image.

Using the pixel dimensions of an image to describe resolution came about with the marketing of digital cameras.

 

Film resolution or printing resolution is not described in terms of pixel dimensions, Its a combination of the lenses and film used to create the images resolution.

Its the same for digital, The quality of the sensor and the optics create the resolution.

 

I'm done now. thanks

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Seems like you've only read what you quoted.

 

Read the rest of what I said... You'll see I agree with you, but I'm also acknowledging that pixel dimensions are a limiting factor for the real resolution that you refer to, and accordingly you could in some cases find that both metrics were the same.

 

;)

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I should add ... If you take that 720x540 image and scale it up to the same *viewing* dimension as you would for your 2k image what would the resolution be then?

 

You see how this discussion is missing the vital component of scaling/viewing distance ? Resolution as the marketers state it is a relative measure, 'dimensionless' if you will - and that is how Noel is getting it wrong.

 

Lines per MM, now that *isn't* dimensionless as it takes into account a screen size (which infers if you will something of which you can measure a viewing distance from). It can be lines per whatever you like, but to compare any two images the 'whatever you like' has to be the same.

 

Without that variable being locked in the discussion will circle around itself getting no where.

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Thanks for doing this work with these lenses to everyone who owns them, I don't know how else we would find this information out. Although the lenses fall short, especially the zooms, what we have is a sensor which could be cropped to HD or maybe even 2K from 2.5K and essentially it is a HD S16mm camera.

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Today, Shane Hurlbut tweeted out a photo showing a vintage 8-64mm Canon C-mount, Super 16mm lens mounted on a Black Magic camera:

 

https://twitter.com/...550409335447553

 

I asked Shane what kind of lens adapter he was using, and he answered simply, "Panavision".. but I've been unable to find an adapter that's being sold that would get me from a Super 16mm lens (C-mount) to a Canon EOS EF mount (what's on the Black Magic)

 

All issues aside about whether the image circle would cover the sensor.. I want to try this for myself.. can anyone help me find / direct me to a proper lens adapter to mount Super 16mm lenses on the Black Magic?

 

I realize this adapter wouldn't really make sense for most cameras.. I've been able to find an adapter to go in the other direction (from EOS glass to super 16mm C-mount camera), but of course, that's not particularly helpful.

 

I'm one of the many still waiting on my Black Magic camera, in the meantime I've done a time-lapse video or two, if you're curious, check out my stuff at http://danieldragonfilms.com

 

Thanks in advance,

Daniel Lowe

work@danieldragonfilms.com

Edited by Daniel Lowe

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Keep in mind if you are using the image circle outside of lens makers intended use that distortion, color, falloff, and resolution might all be substantially different there.

 

Another words, just because it makes an image outside of the S16mm image circle doesn't mean it's a good image outside the S16mm image circle :)

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It might be worth approaching the likes of Abakus about making an adapter that allows Super 16 lenses to be used on the Black Magic camera. There'll be some quality drop off because the image is spread over a larger area, however, it's not as bad doing 16mm to 35mm, which has been done. They did they same for Standard 16mm to Super 16 conversions.

 

http://www.abakus.co.uk/

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I found a proper cine to EOS lens adapter.. next question...

 

If we're talking about which zooms will and won't cover the BMCC sensor, how safe is it to think that c-mount primes would probably do the trick?

Another zoom: There's a ton of Sony f/2 16-64mm lenses out there..

 

I've also had my eye on some 8mm, 9.5mm, and 10mm primes.. an Angenieux 10mm F1.8 can be had for around $200 on ebay.

Thoughts about these options? There's so many c-mount lenses out in the wild.. now, if I could only get my *&^%&* Black Magic camera to test some of these ideas.. been waiting since last August!

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Today, Shane Hurlbut tweeted out a photo showing a vintage 8-64mm Canon C-mount, Super 16mm lens mounted on a Black Magic camera..

 

.. how safe is it to think that c-mount primes would probably do the trick?

 

I'm pretty sure there is no C-mount Canon 8-64, at any rate I've never heard of one. The one in Hurlbut's photo is either PL or a Panavised (PV mount) version.

 

There is no C-mount lens to EOS adapter because the C-mount flange depth is much shorter. EOS lens to C-mount is possible.

 

C-mount lenses might fit on the Micro 4/3 version, though they'd need to sit nearly 2mm inside. It's very unlikely anything under 25mm will cover though, certainly nothing I've measured.

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The 8-64 is a PL mount...Shane was using a PL mount on the Black Magic, I was unaware of this at first.

 

There is no C-mount lens to EOS adapter because the C-mount flange depth is much shorter. EOS lens to C-mount is possible.

 

C-mount to EOS adapters *do* exist. Or at least, I just bought one of these... will it work? I don't know yet, but it's not going to cost me very much to find out...

 

http://cgi.ebay.com/...em=170880750748

 

It will cost me less than $100 for the adapter and a c-mount lens of some kind.. not sure if it will work properly, but I figured it was worth a try since there's so much old Bolex glass out there.

Edited by Daniel Lowe

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C-mount to EOS adapters *do* exist. Or at least, I just bought one of these... will it work? I don't know yet, but it's not going to cost me very much to find out...

 

It will work as a macro lens, no infinity focus. The seller admits it in the listing, stating that focal distances of 5-70 cm are achievable. So nothing past a couple of feet will be in focus. Longer focal length lenses will focus the furthest, wider angles won't focus far at all.

 

C-mounts are designed and collimated to focus 17.52 mm behind the mount seat, EF flange focal distance is 44.00 mm. To work properly, a C-mount would need to be seated 26.48 mm behind the EF mount, well inside the camera.

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C-mounts are designed and collimated to focus 17.52 mm behind the mount seat, EF flange focal distance is 44.00 mm. To work properly, a C-mount would need to be seated 26.48 mm behind the EF mount, well inside the camera.

 

This is good information. Thank you. I've been shopping for alternative glass & thinking through my options; while I'm waiting to get the camera itself. Restless waiting, obviously.

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Ok...

 

SO... Vintage PL mount prime lens would not cover the sensor?

I have a wonderful PL Kinoptik 5.7mm Afraid that won't work in a a BMCC?

THe others I have are PL 16mm and 25mm Schneider lens.

 

Am still wondering if the BMCC worths to buy anyway...

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