is it possible to rack DOF using a 35mm adapter?

[kmper02]

I was thinking that because there are two aperture rings/dials when using a 35mm adapter (one on the camera and one on the lens) it might be possible to change between shallow focus to deep focus during a continuous shot. I have not yet tried it because you need a lot of light, but logically I think it should work.

The way I see it, Have one f-stop all the way open while the other one is at its lowest f-stop before closing. Now simultaneously adjust both aperture dials so that you close the iris on the one that started open, and you open the iris on the one that started one stop before closing. Because the focus on the HVX is on the ground glass of the 35mm adapter, it shouldn't matter if the f-stop is at 16 or 2.4, it should always be in focus. Therefore if you adjust the apertures simultaneously, the light should stay somewhat the same but the Depth of Field should change.

I would love to know if this works. When i have a good amount of lights, i would love to try this out.

Any opinions?

 

[robertwerden]

just tried it, I did not see any difference on my 50mm lens.

 

[kmper02]

can you be more specific? you didn't see anything at all?

 

[Andrew McMillan]

really it sounds like it would work to me, I can even do it on 1/2 inch camera although it gets dark. (no 35 adapter)

 

[Hans Moleman]

the problem is most 35mm adapters dont respond linearly to the 35mm lens fstops. Closing down from an f2 to 2.8 doesn't necessarily mean that the 35mm adapter plane is receiving half as much light.

 

[kmper02]

I see what your saying, but I would imagine there should be some change. I really need to just try this out. When I get some time this week I'll play around.