emulate a 35mm FOV in a 35 mm adapter ?

Just a question, is there a reason why these conversions aren't linear? Say that a piece of Super 35 film is about 1/1.7 the size of a 35mm still frame. Wouldn't you multiply every focal length your using on the Super 35mm film by 1.7 to get the comparable FOV on full frame?

If I were doing the chart I would have made it:
Super35mm Focal Length - Full Frame Film Equivalent
28mm ---- 50mm
50mm ---- 85mm
100mm ---- 170mm
 
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I don't have the conversion ratios, but I am sure that it is even more precise than 1.7, but that is not the point.

There is hardly any difference between a 50 mm and a 47.6 mm. (If it was even available)

There is a difference between a 28 mm cine and 28 mm SLR(framing both with cine crop ). Even when they have the same size they don't have the same qualities. One is a wide angle and the other normal.

I you were to focus both at lets say at 7' one would show a shallower DOF than the other.
 
You can tell this easily by strapping the lenses onto your Letus, honestly.

You don't need PL glass to test your theory.

Put a 50mm on your Letus and zoom the HVX to 27.3 (35mm FOV) Record the image

Then put a 100mm on your Letus and Zoom back out to 20.0mm (SLR) and record the image.

Take the two stills and compare them. Is it the same FOV and DOF?
 
I do. Just that from what I see in my Letus the calculation isn't the same as what you get. A 50mm @ 35mm FOV is not the same as a 100mm @ SLR (20mm) FOV on my Letus. Different FOV, Different DOF.

=B Hey, I even like my HVX @ 40.4mm despite the extra light loss, etc.
 
I was just using whole numbers, but I made it clear that it was not mm to mm.

I personally know what a full SLR lens is suppose to look like. That is why I prefer to use my zoom at 20 mm. Besides it is easier to find super wide lenses (20 mm) that looks super wide.
 
Douglas Villalba said:
I don't have the conversion ratios, but I am sure that it is even more precise than 1.7, but that is not the point.

There is hardly any difference between a 50 mm and a 47.6 mm. (If it was even available)
Click to expand...


I edited my post to make it more clear. I was just trying to say that I, like Kholi, was confused by your saying that a 50mm lens framed for cinema gives the FOV of a 100mm lens framed for 35mm full frame slr.

Douglas Villalba said:
There is a difference between a 28 mm cine and 28 mm SLR(framing both with cine crop ). Even when they have the same size they don't have the same qualities. One is a wide angle and the other normal.

I you were to focus both at lets say at 7' one would show a shallower DOF than the other.
Click to expand...


Are you saying that a 28mm cinema lens and a 28mm slr lens give a different FOV even when they're put on the same sensor (like say a RED camera or a film camera)? This doesn't make sense to me. I use full frame lenses and lenses designed for digital slrs (which have an image circle similar to Super35 size). And they give the same FOV when put on my slr or a 35mm adapter.

Or are you saying there is a difference in FOV and DOF when you zoom in farther on an adapter to go from Vistavision to academy frame size? That I agree with.
 
Douglas Villalba said:
This is what I was trying to say,

This is a link to a TV commercial I did monday for a used car dealer. I used a 24 mm Nikkor to achieve the effect that you see with the cars. If I was using a Cine crop I couldn't have done it.

h.264 5.5 MBs http://www.mediafire.com/?0grimo1jk3j
Click to expand...


Thanks for showing the sample, Douglas.

Achieving a very wide field is great. However, this clip also exhibits an incredibly shallow field that looks unpleasant to my eye.

This is different for everyone, and I did state that special occassions such as commercials, music videos, etc can benefit from it. Again, it's probably preference.
 
I am just not explaining it in a way that everyone can understand.

Look at the video that I posted above. You can see the distortion right? Well that was a $300 dollar 24 mm SLR wide angle lens. Whether you zoom to Cine framing or SLR that lens is still going to show distortion and a broad DOF.

Is you were using a 50 mm SLR lens it is going to look like a normal lens no matter how mush you crop the GG.
 
Yeah I think our wires are gettin' crossed. LoL. S'all good! I think just whatever works best for whoever!

Thanks for the example!
 
Douglas Villalba said:
I am just not explaining it in a way that everyone can understand.

Look at the video that I posted above. You can see the distortion right? Well that was a $300 dollar 24 mm SLR wide angle lens. Whether you zoom to Cine framing or SLR that lens is still going to show distortion and a broad DOF.

Is you were using a 50 mm SLR lens it is going to look like a normal lens no matter how mush you crop the GG.
Click to expand...


Gotcha. Yeah, using a 28mm lens framed on a 1.7x crop sensor will not look the same as a 50mm lens on a full frame sensor even though the FOV is the same.

Where I really find trouble is that most lens makers produce fast normal lenses like 35mm f/1.4 and 50mm f/1.4 for relatively low prices. But you can't find cheap 24mm and 28mm lenses (which are normal when using an adapter or on a APS-C digital camera) in that speed.
 
I zoom into S35mm frame size on my gg, and my experience is that the DOF is the same as 35mm stills, but the FOV is reduced so that I have a tighter crop.

The net result of this, for me is that I have to seek out more and more expensive and rare wide-angle stills lenses (yeah - in Contax Zeiss mount too) to get anything like the same kind of range that Arri 35mm film-making have at their disposal. A set of Arri 35mm primes starts 10mm, 12mm, 14mm, 16mm. Now that is as wide as hell, and I am just trying to get myself a nice 20mm stills lens and a rectilinear (not fisheye) 16mm, but it is not so easy (or cheap).

Does anybody else share this experience?

Lucas
 
That's what I said before about wide angle lenses.

When I used to do photography I never owned a regular lens. I just don't like to see through the camera the boring stuff that I see every day with my eyes. (Portrait photography)

Now what I still don't get is why crop to anything that the lens was NOT design to do.

I can see that with some cases where you get some vignetting or you want to control DOF, but for most of my shooting it is FULL SLR.

I like to control where my audience has their attention and I know how to do it this way.

You may not like what I do. That is matter of taste. To each it's own.
 
Lucas Adamson said:
I zoom into S35mm frame size on my gg, and my experience is that the DOF is the same as 35mm stills, but the FOV is reduced so that I have a tighter crop.

The net result of this, for me is that I have to seek out more and more expensive and rare wide-angle stills lenses (yeah - in Contax Zeiss mount too) to get anything like the same kind of range that Arri 35mm film-making have at their disposal. A set of Arri 35mm primes starts 10mm, 12mm, 14mm, 16mm. Now that is as wide as hell, and I am just trying to get myself a nice 20mm stills lens and a rectilinear (not fisheye) 16mm, but it is not so easy (or cheap).

Does anybody else share this experience?

Lucas
Click to expand...

It's hard to find rectilinear primes, I'll tell ya that. I mean, they're out there, but that' an extra 200+ Per lense.

Honestly, if it's a huge issue then move away from Super35 framing? I haven't seen it as an issue myself although I still want a 14mm prime to have.
 
And 14mm SLR prime gives wider field of view than 10mm Zeiss Ultraprime for S35 cinema frame size for given proper frame size for SLR lens so it would be wonderful if an adaptor sported regular SLR frame width without vignetting and soft edges etc...
I don`t know if I should trash that 35mm lens adaptor business altogether or invest another $2000 (when imported to EU) to get flipped Brevis that hopefully will give me the actual field of view without vignetting or edge softness with lens that extreme as the 14mm f2.8 FD L rectilinear that is absolutely wonderful when used for photography.

With all the "blah" about 50mm lens to get as normal starter lens it would make no sense when used on Academy (1.7x crop) frame size. So there we have all the people having 50mm lens as normal lens on 1.7x cropped field of view. In terms of photography theory it would only give DOF properties and perspective but not the field of view, still or moving images. If one wants to get a wide shot with SLR lenses one gets 24mm or 28mm for normal wide shot when used on full frame but if you crop it as much as 1.7 or so you`ll end up with a medium shot instead - what would director say about that.
And let`s say you are a director who is using 35mm still photography lenses for movie making with cropped field of view you must be aware that you can not get the same field of view and to get the same you must use wider lenses. Cine lens are always marked with smaller focal lengths just because of that as are our camcorder lens marked with something close to 5-50mm (instead of 35-350mm) because we have such small sensors in our camcorders when compared to film. And that 35mm equivalent marked besides most camcorder specs is the focal length (field of view) equivalent of 35mm still photography lens and not cinema/Academy lens.

Cheers,
T
 
I'll tell you what I've heard from directors: Uhm, we're not using SLR glass. We'll spend the money to rent Zeiss PL Glass.

Which is why I bought the mount. I'm just sayin'... =B Get a Brevis, though. It's SLR FOV.
 
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