Idea for a lens/camera test - thoughts

[Johnny Liu]

I had this idea to try a test with a Bolex handheld 8mm camera such as a C8/B8/D8LA.  These all take D mount lenses and I thought of using a C to D mount adapter - and then stack it with something like an EF to C mount adapter or a PL to C mount adapter.and then rent a modern cinema lens like a Zeiss CP.3 prime lens -- and then use a good film stock like Vision 3 50D - to run a film test.  I would also use a base plate, support rails, and a lens support to support the weight of this modern cinema lens.  I'm mainly interested to see how far one could push the sharpness of 8 mm film.  Any ideas, thoughts, or comments you have about this test plan - please let me know!

Edited March 24 by Johnny Liu

[Mark Dunn]

Of course the lens would be very long on 8mm, but maybe that wouldn't matter for a test. My thought would be that a modern lens is sharper, but not all that much sharper, and that the limiting factor is a frame smaller than your little toenail. 8mm. can look very good with a modern high-res scan; maybe it doesn't get much better than that.

Edited March 24 by Mark Dunn

[Dom Jaeger]

I think a Bolex H8 RX with H8 RX Switars, properly serviced, will give you about as sharp an image as 8mm can achieve.

Using a pocket Bolex like a B8/D8 you’ll be relying on the lens focus scale, which could easily be out using stacked adapters. And the pocket cameras don’t have the same registration stability as a H8 with a fixed sprocket-driven loop and better gate and pressure plate.

If you really wanted to test the resolution capabilities of an 8mm sized film frame, you could just crop such a frame from the centre from a high res scan of 16mm footage shot on something like an SR3 with Ultra 16 lenses, or an Arricam with Zeiss Supremes. Then compare it to the H8RX footage and see if it looks any better.

[Johnny Liu]

3 hours ago, Mark Dunn said:

Of course the lens would be very long on 8mm, but maybe that wouldn't matter for a test. My thought would be that a modern lens is sharper, but not all that much sharper, and that the limiting factor is a frame smaller than your little toenail. 8mm. can look very good with a modern high-res scan; maybe it doesn't get much better than that.

Thanks for your thoughts on this!

[Johnny Liu]

2 hours ago, Dom Jaeger said:

I think a Bolex H8 RX with H8 RX Switars, properly serviced, will give you about as sharp an image as 8mm can achieve.

Using a pocket Bolex like a B8/D8 you’ll be relying on the lens focus scale, which could easily be out using stacked adapters. And the pocket cameras don’t have the same registration stability as a H8 with a fixed sprocket-driven loop and better gate and pressure plate.

If you really wanted to test the resolution capabilities of an 8mm sized film frame, you could just crop such a frame from the centre from a high res scan of 16mm footage shot on something like an SR3 with Ultra 16 lenses, or an Arricam with Zeiss Supremes. Then compare it to the H8RX footage and see if it looks any better.

Thanks for your insights into this.  Didn't think that focus might be affected by stacked adapters.  I just thought that if someone made an adapter, they probably measured/manufactured it correctly, but I guess that would be an assumption!

I was thinking about getting an H8 to run the test with, but I already have a serviced/CLA'd B8 on hand, so just though of using the B8 for my test instead of spending the time and money to buy an H8 and get it CLA'd.

Edited March 24 by Johnny Liu