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-   -   Arri Glass on a 7D? (http://www.dvinfo.net/forum/canon-eos-crop-sensor-hd/486196-arri-glass-7d.html)

Andrew Slankard October 15th, 2010 04:10 PM

Arri Glass on a 7D?
 
Assuming that the user acquired a PL-mount adapter for the 7D, would it be worth it to rent Master Primes to use with it? Or would the 7D's sensor not benefit from glass that nice? A buddy of mine in film school said something to the effect of the 7D's are widely used by film students because their sensors are similar to Red One's (though he couldn't have been talking about the M-X sensor, could he?)

Anyway, Arri Master (or Ultra) Primes + 7D = worth it?

Jonanthan Carr October 15th, 2010 06:10 PM

the only thing close that the 7D has to the RED one M or MX sensor is size. 7D sensor size is 22.2mm x 14.8mm (1.5:1) and the RED one is 24.4mm x 13.7mm (1.78:1). Why students use it instead of the HVX or EX1 anymore is because of the size of the sensor. Basically the bigger the sensor, the shallower the depth of field is, and better the signal to noise ratio should be. Students want that Shallow depth of field, and they want it cheaply. The 7D might look nice at high ISO's but the noise floor is no where near as low as the RED MX sensor. Now about sharpness and putting nice PL lenses on, the 7D might look like they're shooting sharp, HD footage, but no, they're not. If you shoot a resolution chart, it'd look around a standard-definition camera, or a 720p camera. Any real crisp sharpness you see in the image is just aliasing of the image. So putting Master primes with make no real difference then putting regular non L series canon lenses. The only real advantage to putting on PL lenses is less lens breathing and pulling focus better.

7D resolution test

http://www.dvinfo.net/forum/eos-7d-s...sing-test.html

Liam Hall October 16th, 2010 08:56 AM

There are only two ways to use PL mount lenses on the 7D, first is to hack off the Canon mount and remove the mirror - due to the increased flange distant of PL mount lenses - and the other is to use an optical relay lens - which negates most of the benefits of using the cine glass in the first place.

A better option would be to use cine lenses that are designed to be used with DSLRs like the Zeiss CP2s.

Jeremy Hughes October 28th, 2010 11:54 PM

I think PL lenses - fast lenses - are a benefit to the final footage you can get out of the camera. If you can put super speeds on there, theres a difference on several levels. Quality is at least similar to L series but you get the look and feel of that lens. Its bokeh, etc. Being able to shoot and accurately pull focus is a huge benefit as well. The cleaner the glass, the better the codec does in anything I have worked with.

Charles Papert October 29th, 2010 09:16 AM

There is absolutely a difference when you use different lenses on these cameras, even in video mode where much of the resolution is killed between the sensor and the codec. The expression "garbage in, garbage out" comes to mind, although I'm certainly not saying that the Canon lenses are garbage. I use the Zeiss ZE's with my 1DMKIV and often have to resort to the Canon zooms for convenience but there is a palpable difference between them. I just finished shooting a pilot for FX and we shot with a variety of lenses including the CP2's; my AC's said that their clarity was night and day compared to the Canons in the high contrast, low light setting we shot in.

The PL concept is very cool but I'm personally not much of a fan of the 7D, being that the noise floor is not much greater than many other camera choices out there, which is why I shoot with the 1D. Unfortunately wide cine lenses won't cover that camera's sensor, so doing a mirror conversion isn't in the cards. However I find the CP2's an acceptable compromise (and because I use remote focus, the short throw of the ZE's are as good as the CP2's in all ways except the external iris ring). I very rarely want to shoot under a 2.8 so the speed of the lenses are fine for me. I will admit to shooting a night scene in a music video recently at f1.4 on the 50mm ZE at 5000 ASA, but the subject wasn't moving much (and the sky looked unbelievable, like a combination of night and day, reminiscent of a Magritte painting).

Master Primes are beautiful lenses but they are big, heavy and expensive to rent--in a PL situation I'd probably opt for Ultra's, or for many projects, the two baby Optimos and the 24-290.

So anyway: yeah, it's worth shooting with great glass but at a certain point, the cost may not be worth the limitations of the capture device--depends on the project.

Gabe Spangler October 29th, 2010 03:29 PM

Charles, don't you mean the long throw of the ZE's focus ring, not the short throw? I also shoot on the ZE's. And although the focus ring has a long throw (compared to most still lenses), I do have one gripe. Most of the focus rotation covers the short distances, like 18" to 5'. The focus rotation for the intermediate ranges, like 5' to 10', is very short. So pulling focus on a dolly move from, say 10 feet to 4 feet from the subject, is very, very hard, nearly impossible, especially at wide iris settings. Of course Zeiss will never change that, because then there is no reason to own or rent the CP.2s. Other than that, the Zeiss ZE's are superb in both functionality and image quality.

Charles Papert October 29th, 2010 05:24 PM

I was comparing the ZE's to the CP2's or any cine lens, so in that context, they are indeed short-throw. For the reasons you described, I never use them with a mechanical follow focus, I use my Preston full-time regardless of shooting mode (studio, Steadicam or handheld). Once programmed in, the feel for the AC is exactly the same as any cine lens; they get 300 plus degrees on the knob and accurate focus marks down to 3" increments (depending on where they are on the lens and how the Preston is configured). It's not a setup that I suggest anyone purchasing simply to use with DSLR lenses, it's way too expensive for that, but it does help things tremendously if you happen to own one!

Gabe Spangler October 29th, 2010 05:48 PM

Ah ha. Gotcha. Yes, the follow focus abilities of stills lenses, even the ZE's, are limited. You must design your shots around their limitations in the focus department.


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