Another 35mm adapter question (have searched for answers)

H

huckfinn

Member
Hi,

I've got a problem with my diy 35mm adapter. Maybe someone can help me with it, cause I couldn't find answers or relevant info in those thousand topics on messageboards about this subject.

My setup is quiet simple:
Camera (Sony DCR-TRV50e) || +10 Macrolens || double opaque plastic focal screen || Canon 50mm 1.8

I focus the camera on the focal screen, zoom in and move the Canon lens so that I get a sharp image when the lens is set to infinity.

So - My LCD correctly shows the typical static grainy, upside down image , but: somehow I can't focus on specific objects (the whole reason why we build the dof-adapters). Nothing much happens.

I've put a video on youtube that shows what I mean. In the video I'm turning the ring of my Canon lens from 2ft to 10ft and back, yet most of the picture remains in focus: http://www.youtube.com/watch?v=0Qg3Ke7NYaE (I've reduced the quality much).


Anyone knows what I'm doing wrong, or someone had the same problems that I have and knows how to solve it? Of course this is the result I wanna get: http://www.youtube.com/watch?v=Y4QiTHRQbfA

Thanks!

P.S. This is my first post. I'll introduce myself later!
 
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post a pic of your set up. shoot from the side so we can see the relative distances of the elements of your diy rig.

what aperture is your canon lens at? your youtube vid is too lossy to guage it cleary.

Ted
 
I already deconstructed the adapter, so on this photo I'm holding together the pieces exactly as they were glued.
picture0012gb3.jpg


The aperture of the lens is 1.8. I'll try to upload a better version of the vid.

Thanks for the reply.
 
The distance from your Canon lens mount flange and your imaging plane needs to be 44mm for EOS and 42mm for FD. My guess is that it's a few mm off, which is placing the focus range of your lens in front or behind your opaque screen. You're probably not getting sharp focus at infinity!
 
Dennis is right. if that line pointer you labeled focal screen is exactly where your "focal screen" is then you need to check your focus at infinity.

another thing for us to better help you. Try to measure in mm the image size that your camcorder is capturing on your "focal screen".

Place your setup on a stable surface.
make sure you tape down your adapter to a stable support that will support it when you remove yoyr camcorder.
Shoot a grid pattern. take note of the framing in your monitor or lcd, then mark with a pen the grid pattern to correspond to the edges of the frame you see on your LCD. Take off your camcorder leaving the adapter. look through your "focal screen" and measure the image size of the pen marked grid pattern on this screen.

You should be getting an image around 24+ mm across.

From here we will work on the quality of your +10 macro then to your screen.

Ted
 
Dennis Wood said:
The distance from your Canon lens mount flange and your imaging plane needs to be 44mm for EOS and 42mm for FD. My guess is that it's a few mm off, which is placing the focus range of your lens in front or behind your opaque screen. You're probably not getting sharp focus at infinity!
Click to expand...

Sorry to stray from the focus of the topic, but do you know what this distance would be for Nikon AF Nikkor lenses? Or where I might find this information?
I'm about to attempt my first adapter build and I've got a few Nikon lenses laying around that I'd like to try it with.
 
theres a definite measurement for that, i believe is also roughly 45mm, but to be precise, look for the film plane indicator in the nikon body, thats the circle with a line through it. like a saturn. that line measured to your lens mount rim is your distance.
 
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