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View Full Version : would this vignette? Canon 8mm-64mm 2.4



laco
05-05-2012, 10:21 AM
Hurt locker was shot on 16mm cameras, and they mainly used two Canon zooms:
the Canon 8-64mm 2.4, and the Canon 11-165mm 2.4 which were designed to super16 mm cameras

I know, that currently we can't mounty any of these lenses because of the shorter flange distance of these lenses. But even if we could, would they vignette, or cover the BMC's sensor?

The only thing I would like to see from BlackMagic is an upgrade path, if they will come out with another lens mount.

Barry Green
05-05-2012, 11:43 AM
Definitely significantly vignette. The BMC's sensor is twice as big as Super16.

Harry Lime
05-05-2012, 12:09 PM
The BMC sensor is not twice as big as S16. It sits in-between S16 and M43, which is problematic. It eliminates almost all S16 lenses and the EF mount makes it impossible to use M43 glass. The BMC sensor is a rather awkward size, if you need lenses on the wide end. Slow zooms (f2.8 / Tonika etc) could make it difficult to match the DOF of S35, which is a lot easier to do with the fast S16 glass that is available (T1.4 and faster)


http://camerarentalz.com/wp-content/uploads/2012/04/blackmagic-camera-sensor-size.png

http://camerarentalz.com/wp-content/uploads/2012/04/blackmagic-camera-FF35mm-comparison.png

Barry Green
05-05-2012, 12:29 PM
The BMC sensor is not twice as big as S16.
Doh. It isn't twice as big, no. It's twice as big as 16mm, not twice as big as S16.

S16 (especially in 16:9, which is the only fair way to compare it) = 12.4 x 7, or 86.8 square mm.
The BMC is 15.6 x 8.8, or 137.28 square mm.
137.28 / 86.8 = 1.58.

The BMC sensor is 1.58x bigger than S16.


It sits in-between S16 and M43, which is problematic. It eliminates almost all S16 lenses and the EF mount makes it impossible to use M43 glass. The BMC sensor is a rather awkward size.
Again, it's not the sensor that's the problem, it's the (IMO) ill-chosen EF mount that causes the problem. With a change of mount there'd be no problem.

Harry Lime
05-05-2012, 02:25 PM
Again, it's not the sensor that's the problem, it's the (IMO) ill-chosen EF mount that causes the problem. With a change of mount there'd be no problem.


I think it's a combination of problems.

The EF mount certainly does not help. I think that was intended to make the camera appeal to the current 5D crowd, but from the point of view of a cinematographer it's a pretty bad choice given the vastly different size of the sensors and wide-angle glass available. There is also no way to adapt it to PL, unless you replace the whole mount and front plate. And even that does not solve all out problems, because a 'dumb' M43 mount without the electronics to talk to the BMC body will not be able to adjust the aperture and focus on a lot of those lenses.

M43 certain would make things a lot easier. It may as well be called the universal mount since it can be converted to pretty much anything given the correct adapter.

But even with a M43 mount converted to PL via an adaptor most S16 glass will simply not cover the BMC sensor without vignetting. The image circle of these lenses is simply too small. The BMC sensor is an oddball size that is going to make things complicated.

So we are in a tight spot.

Yes there are wide-angle M43 options out there, but these are still photography lenses, not dedicated cine lenses. For the most part they are relatively slow, most will breath, their focusing coils do not operate in a linear fashion, many are "focus by wire" that requires electronic interfacing, aperture rings are sometimes nonexistent etc. Also is there a fast 10mm or 11mm out there in the T1.5 or T2 range? Yes, you can make still photography lenses work, but compared to a real cine lens they are a PIA.

Duclos makes a modified Tokina 2.8/11-16mm. They add an aperture ring, PL mount and beef up the internal constructions, but I believe it still focuses like a still lens. f2.8 at 11mm gives you roughly the equivalent of a 25mm at f5.6 or so on S35. That's not too bad, since most movies are shot around that stop (f4-5.6ish. The actors need a little DOF to move around.)

http://ducloslenses.myshopify.com/products/duclos-11-16mm

That's a step in the right direction, but it's $3k and 6 months backordered....



All of that said, I still would go ahead an buy one and work around the limitations. Maybe we'll get lucky and there will be a S35 or APS-C version out next year. In the meanwhile BM would be REALLY SMART if they offered a version with M43 mount.

Pietro Impagliazzo
05-05-2012, 03:45 PM
I really wish this camera was M43. M43 is a nice sweet spot IMO, specially with its moderate (or bigger than moderate?) acceptance now.

Osslund
05-05-2012, 05:50 PM
The more I get to use 4/3 size cameras the more I love it. It seems to be a very good size when weighting in all the factors. Shame this camera doesn't take advantage of an appropriate mount.

joesiv
05-08-2012, 01:27 PM
Doh. It isn't twice as big, no. It's twice as big as 16mm, not twice as big as S16.

S16 (especially in 16:9, which is the only fair way to compare it) = 12.4 x 7, or 86.8 square mm.
The BMC is 15.6 x 8.8, or 137.28 square mm.
137.28 / 86.8 = 1.58.

The BMC sensor is 1.58x bigger than S16.
What's interesting (and perhaps even elegant) is that in 1080p mode which is cropped, you are very very close to S16...

laco
05-08-2012, 03:57 PM
1080p mode isn't cropped. It's downlscaled.