Some MINI and PRO questions

Barry Green · January 28th, 2004, 01:55 PM

<<<-- Originally posted by Mizell Wilson : Barry,

What we're trying to hash through is the conversion factor for achieving similar compositions between formats e.g. Hope this clears up the confusion.

mizell -->>>

Okay, cool. That's easy. Here's a chart that converts angle of view among basically every film and video format made:

http://www.edward.grabczewski.btinte...le_of_View.xls

From that chart it looks like a 50mm on a still camera delivers the same field of view as a 30mm on a movie camera. And a 175mm on the still camera would match the FOV of a 100mm on the movie camera.

Mizell Wilson · January 28th, 2004, 02:22 PM

Cool Barry, great find!!!!

Charles Papert · January 28th, 2004, 04:47 PM

Ahh, that is a goodie. Sorry I wasn't making myself clear, even after my attempts at clarification!

It looks like 1.6 is a good number then, give or take a bit. I'm still wondering if there is a loss or gain in field of view due to the re-photographing aspect of the Mini35 setup, which I think I will just have to wait and see until I can do a side-by-side comparison with a film camera.

My interest here is mostly if I was presented with a still lens-equipped Mini35, how to choose the appropriate lenses since I am used to thinking 35mm cine focal lengths.

A couple of thoughts about this: since the still lenses are designed to work with a larger target than the cine lenses, would it not be the case that on a Mini35 we are only using the center of the still lens, which would help with edge distortion/chromatic abberation-type issues, if present?

And here's another thought for discussion: if the Mini35 theoretically had a target size similar to a 35mm still camera rather than a cine gate, would you not be realizing a decrease in depth-of-field (i.e. shallower) given the same field of view? In other words, we are using a (theoretical) 30mm cine or still lens on the Mini35 to achieve a particular composition, but if a 50mm still lens was used on an imaginary version of the Mini35 with a larger ground glass and the appropriate relay lens, we would net the same composition but less depth of field, due to the longer focal length. If this is so, perhaps the Agus35 crowd may be getting even more bang for their buck, if they are capturing a full 35mm still frame

Mizell Wilson · January 28th, 2004, 04:52 PM

Hey Charles,

Yes, theoretically we are using more of the center of the still lenses, helping to increase their overall quality...one reason why I think they're holding up to the cine lenses so well.

The Mini35 could certainly have a still sized image screen. The unit actually started out capturing S35, for that extra tad of shallow, but the problem existed that almost all cine zooms and some older primes were never designed to cover S35, resulting in the soft vingettes that were reported early on. So for maximum compatibility with maximum results the Academy 35mm was chosen.

mizell

John Jay · January 28th, 2004, 05:53 PM

Now that we seem to be in agreement, is it not time for P+S to consider a version Mini35_SP (Special Performance) to account for the larger SLR frame with the appropriate change to FFD?

This will be essential, especially to capitalise on say the Nikon 35mm f1.4 which has amazing point of presence properties and would very likely suck the audience out of their chairs and into the film.

I would love to see a blow up with such a setup

as far as CA and BD distortion, After Effects Plugins are sufficiently well developed to rectify any present and could easily be incorporated into a work flow along with breathing issues (which incidentally only account for about 3% image scale over the whole travel of the focus ring)

FYI

http://www.mir.com.my/rb/photography...kkor/index.htm

Mizell Wilson · January 29th, 2004, 02:10 PM

I doubt we'll see a version of the Mini35 designed to use the full 35mm still aperture for many reasons.

One is that I think one reason we're getting such great results with the Nikon lenses is because were not using the full image circle.

There is also the relay lens to consider. Reducing the Still image circle to 1/3" would start to stretch it's capabilities.

With those two things combined I think we would see a lot more of edge distortion than might otherwise not be seen because of how forgiving film can be.

Never say never though :)

January 28th, 2004, 02:22 PM	#17
Mizell Wilson Sales: Reflecmedia Join Date: Jan 2002 Location: Linden, NJ Posts: 147	Cool Barry, great find!!!! __________________ Posts before Feb 2004 were on behalf of ZGC, afterwards they're all mine!

January 28th, 2004, 04:47 PM	#18
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	Ahh, that is a goodie. Sorry I wasn't making myself clear, even after my attempts at clarification! It looks like 1.6 is a good number then, give or take a bit. I'm still wondering if there is a loss or gain in field of view due to the re-photographing aspect of the Mini35 setup, which I think I will just have to wait and see until I can do a side-by-side comparison with a film camera. My interest here is mostly if I was presented with a still lens-equipped Mini35, how to choose the appropriate lenses since I am used to thinking 35mm cine focal lengths. A couple of thoughts about this: since the still lenses are designed to work with a larger target than the cine lenses, would it not be the case that on a Mini35 we are only using the center of the still lens, which would help with edge distortion/chromatic abberation-type issues, if present? And here's another thought for discussion: if the Mini35 theoretically had a target size similar to a 35mm still camera rather than a cine gate, would you not be realizing a decrease in depth-of-field (i.e. shallower) given the same field of view? In other words, we are using a (theoretical) 30mm cine or still lens on the Mini35 to achieve a particular composition, but if a 50mm still lens was used on an imaginary version of the Mini35 with a larger ground glass and the appropriate relay lens, we would net the same composition but less depth of field, due to the longer focal length. If this is so, perhaps the Agus35 crowd may be getting even more bang for their buck, if they are capturing a full 35mm still frame __________________ Charles Papert www.charlespapert.com

January 28th, 2004, 04:52 PM	#19
Mizell Wilson Sales: Reflecmedia Join Date: Jan 2002 Location: Linden, NJ Posts: 147	Hey Charles, Yes, theoretically we are using more of the center of the still lenses, helping to increase their overall quality...one reason why I think they're holding up to the cine lenses so well. The Mini35 could certainly have a still sized image screen. The unit actually started out capturing S35, for that extra tad of shallow, but the problem existed that almost all cine zooms and some older primes were never designed to cover S35, resulting in the soft vingettes that were reported early on. So for maximum compatibility with maximum results the Academy 35mm was chosen. mizell __________________ Posts before Feb 2004 were on behalf of ZGC, afterwards they're all mine!

January 28th, 2004, 05:53 PM	#20
John Jay Major Player Join Date: Sep 2002 Location: US & THEM Posts: 827	Now that we seem to be in agreement, is it not time for P+S to consider a version Mini35_SP (Special Performance) to account for the larger SLR frame with the appropriate change to FFD? This will be essential, especially to capitalise on say the Nikon 35mm f1.4 which has amazing point of presence properties and would very likely suck the audience out of their chairs and into the film. I would love to see a blow up with such a setup as far as CA and BD distortion, After Effects Plugins are sufficiently well developed to rectify any present and could easily be incorporated into a work flow along with breathing issues (which incidentally only account for about 3% image scale over the whole travel of the focus ring) FYI http://www.mir.com.my/rb/photography...kkor/index.htm __________________ John Jay Beware *PLUGGER-BYTES*

January 29th, 2004, 02:10 PM	#21
Mizell Wilson Sales: Reflecmedia Join Date: Jan 2002 Location: Linden, NJ Posts: 147	I doubt we'll see a version of the Mini35 designed to use the full 35mm still aperture for many reasons. One is that I think one reason we're getting such great results with the Nikon lenses is because were not using the full image circle. There is also the relay lens to consider. Reducing the Still image circle to 1/3" would start to stretch it's capabilities. With those two things combined I think we would see a lot more of edge distortion than might otherwise not be seen because of how forgiving film can be. Never say never though :) __________________ Posts before Feb 2004 were on behalf of ZGC, afterwards they're all mine!

January 28th, 2004, 01:55 PM	#16
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	<<<-- Originally posted by Mizell Wilson : Barry, What we're trying to hash through is the conversion factor for achieving similar compositions between formats e.g. Hope this clears up the confusion. mizell -->>> Okay, cool. That's easy. Here's a chart that converts angle of view among basically every film and video format made: http://www.edward.grabczewski.btinte...le_of_View.xls From that chart it looks like a 50mm on a still camera delivers the same field of view as a 30mm on a movie camera. And a 175mm on the still camera would match the FOV of a 100mm on the movie camera.