need a little help with my DIY 35 adapter

bmxbud4130

bmxbud4130

Active member
I finally got my first DIY adapter pieced together, but am having trouble.
I'm trying to build a vibrating adapter with nikon lens and a 10+ macro in a project box.

First, I can't get the image to fill the screen. I've got a ton of vignetting. I can zoom in, but everything goes way out of focus.

I'm wondering if the lens to ground glass distance is off. Or possibly the distance from my ground glass to the 10+ macro I have on my DVX? I'm not even sure what this distance should be???... any magic number to this?

Second, perhaps my ground glass isn't 'frosted' enough? I figured if you can use a dummy CD for a ground glass in a spinning design then I could use an acrylic sheet.


I have photos but wont be able to post them for a couple of days (i'm moving into a new place and don't have the 'net connected on my machine yet).

So anyhow...
-how far should the 35mm lens be from the ground glass?

-how far should the 10+ macro be from the ground glass?

-would adding additional macro lenses (+2, +3, etc) help me fill the screen with less vignetting and still allow me to focus?
 
my ground glass is just a sheet of clear plastic that i bought at lowes.
to frost it i put it between a couple sheets of 220 grit sand paper and basically clapped my hands on it for awhile.
doing this for awhile put fine little dots onto it rather than scratches. i thought this method might give better/less grain, and i was afraid that scratches might show up on screen more than a little grain would.

if you look at this photo you can see a little bit of the grain on my 'glass'.

http://i25.photobucket.com/albums/c54/bmxbud4130/DIY/PB250064.jpg


after looking at what a real ground glass is supposed to look like, i think i might need to get the sand paper back out...

here's what the inside of the box looks like without the motor:
http://i25.photobucket.com/albums/c54/bmxbud4130/DIY/PB250071.jpg

and this is what it will look like once it's finished:
http://i25.photobucket.com/albums/c54/bmxbud4130/DIY/PB250071.jpg
 
1. that plastic is not frosted enough. look at an slr's focus screen so youll get an idea.

2. if you intend to have a vibrating gg, that mount wont give you a sharp image as it will vibrate in the z axis as well as y and x.

what lens mount are you using? nikons have different flange depth from canons and so on.
 
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1. after inspecting what a real ground glass is supposed to look like, i feel like a dummy. i'll break out the sandpaper and go to town... or... i might just order a ground glass from here: http://www.sciplus.com/category.cfm/subsection/21/start/78/maxrows/11

2. how else can i mount it to limit it to vibrating only on the x and y axis?

3. for the lens mount i'm using the rear lens cap from the nikon lens. maybe life would be easier if i ordered a regular old lens mount instead?

4. should i just go back to the spinning design with the clear CD? ha


like i said, this is my first attempt at an adapter, so i appreciate you being patient with my ignorance. ha
thanks for all of your help.
 
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