academy field of view

reem12

reem12

Veteran
I have a question concerning making my hvx 200 and canon a1 match up with sg pro 35mm adapter in terms of feild of view.

I'm still sort of ignorent when it comes to this, but If I use one cam with an adapter and one without it, will the feild of view match up?

And can someone kind of explaine to me how all of this work to basicly get the feild of view from my bare camera that I see on the big movie screens.

Thanks
 
Answer is simple but sad: no. It will not have the same FOV, especially not academy FOV, but you can work towards it, so that the difference won't be that big anymore.
 
Barry posted something about this in another thread, but I can't seem to find it right now. Barry? Where are you? haha.
 
Quoting a passage written by Barry Green (hope you don't mind, Barry) from an article on the Letus FE:

Having read many posts by various users about the struggles they have with many different adapters when trying to achieve good edge-to-edge sharpness and minimizing vignetting, I’m becoming convinced that lots of people (users and even some of the manufacturers) may not necessarily know what the proper configuration should be for one of these adapters. The goal should be to mimic the depth of field and field-of-view of a 35mm movie camera – that’s what the mini35 does, and that’s what you want to do to have a constant frame of reference and predictable results. A 35mm movie camera has a frame size of about 22mm x 16mm, not the 36mm x 24mm size of a still camera. What you want to do is zoom in to the ground glass far enough that you set up your field of view to match what a 35mm movie camera would see, using the same focal length lens at the same distance. An easy way to do that (and get pretty darn close) would be to use an 8.5 x 11” sheet of paper, taped to a wall sideways (i.e., “landscape” orientation), and set your camera about two feet away from it. With a 50mm lens, focused at 2’, you should be just cropping off the edges of the paper (ideally you’d have about a 10.5” wide field of view from two feet away when using a 50mm lens). If you configure your zoom such that you’re just cropping off the edges of the paper, you’re basically matching the field of view of a 35mm movie camera at that point.
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I keep my HVX zoomed at '27mm' for academy and about '22mm' for 'as wide as possible without too much vignette'. All depends on the lens. I hope this helps you match the SG Pro.
 
Barry and I discussed this very point at NAB. Many of our users don't care about academy format at all and the majority want the maximum field of view possible from a given lens format. For example, if you purchase the very nice 17-35mm f2.8 Nikon lens and then proceed to zoom in to academy, your nice 17mm will return the field of view of say a 35mm lense. In that sense, you just threw away the wide angle shot you wanted and spent all that money for. Our philosphy in R&D has always been to provide a field of view equal to, or in excess of, what the lens is capable of. It is a much more difficult challenge to do this, however the reward is that the shooter can decide to frame SLR or Academy with no/low vignetting and edge sharpness...thereby using the maximim field of view possible. I can tell you that adapters out there vary wildly in usable field of view. Very, very few can exceed 36mm frame width which is possible when framing 16:9 over the 35mm image cone. Some cameras we've tested like the HV20 lose nearly a full stop at the frame edges when fully zoomed in...so zooming to academy with cameras like this will likely introduce a large amount of edge fall-off, even with a "perfect" adapter.

Many of our users use our PL mount with rented Cine lenses..and that's when they generally frame academy format. With the Brevis MP.1 and CF1Le what we've seen is that cine lenses over 50mm focal length, can actually be framed like an SLR lens at 36mm frame widths. That's pretty crazy but it means that you have a lot of flexibility in framing those lenses. This would likley drive a DP crazy, but the option is indeed there :-)

If you want to match adapter footage with non-adapter footage, shoot wide with the bare camera, and make sure your subjects are a few meters away. A 35mm wide angle lens will typically be at infinity focus with your subject a short distance away ... so it will look similar to the bare camera in this scenario.
 
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A good reason to shoot with academy framing is that you can then use standard DOF charts (e.g., American Cinematographer's Manual) to know what your DOF is for a given lens. (Doesn't anybody use those anymore??)
:)
 
Dennis do you have any samples of the PL mount in action? I never see any footage that is noted for its cine glass.
 
Search the names Faisal Lutchmedial, Paul Nordin, or Chad Terpstra in our forum footage section. Also check out the FreshDV stuff on pulling focus, as well as the Brevis Rev2 review. All done with our PL mount and Cook lenses. We have many PL mount users who typically use Nikon lenses for their own work and rent cine lenses for production. As I type this 2nd City in Toronto is using a Brevis/HVX200 with PL lenses for four episodes of the series airing nationally under the tutelage of Curtis Jensen, one of our local customers.

Once you use a cine lens on the system it's hard to go back. It's not necessarily a dramatic increase in sharpness, as some of the new SLR lenses are outstanding, but rather the low breathing and very accurate focus of these lenses. Our Lomo OCT19 cine lenses have a quality that we've yet been able to describe. They're sharp, yet impart a very organic quality to the images. It's like a low pass filter is being executed in the bokeh areas.
 
Dennis Wood said:
Many of our users use our PL mount with rented Cine lenses..and that's when they generally frame academy format. With the Brevis MP.1 and CF1Le what we've seen is that cine lenses over 50mm focal length, can actually be framed like an SLR lens at 36mm frame widths. That's pretty crazy but it means that you have a lot of flexibility in framing those lenses. This would likley drive a DP crazy, but the option is indeed there :-)
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You should be able to do that with all adapters.. 50mm's gonna naturally have larger elements.

How did you figure the 50mm PL Mount lens framed at SLR would equate to about 35/36mm lens?

I figured as much, but was looking for an actual mathematical phrase to go by. Because if you can get 35mm FOV out of a 50, then you can get about an 85 out of it too by zooming in as far as you can. Already knew it existed as a "cheat" but just needed to figure out some round-about numbers. Want to use this trick really soon on a test.
 
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