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My DIY Alpa style shift camera

yongfei

New member
I am building an Alpa style DIY camera. I find the biggest challenge is to get the flange focusing distance correct. Right now, it can only focus at an object at 5 foot away when the focusing scale is set at infinity. I still need to shorten the camera body for 2-3mm.

It uses a CFV back, Rodenstock 55mm lens. So I should be able to get 3 stitched pictures.

Here are the photos:


 
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Jack

Sr. Administrator
Staff member
You may want to load your images to our gallery as your host site prohibits direct linking...
 

Guy Mancuso

Administrator, Instructor
Might have to use a router in the lens board area and mill that inside a bit and get it closer to the sensor. Than you could use shims inside.

Looks pretty cool
 

yongfei

New member
That is a good idea, especially for fine adjustment within 1mm. I have a Dremel tool. Thanks for the input. Never thought about that...

What will be the best shim material? Maybe some aluminum or brass plate from Hobby Lobby? BTW, I bought this aluminum sliding rail part from Home Depot for $5.

Might have to use a router in the lens board area and mill that inside a bit and get it closer to the sensor. Than you could use shims inside.

Looks pretty cool
 

robmac

Well-known member
From my #$%^& Canon 5D focus screen shimming days ($%^&) - metallic duct tape is 0.001" thick - BUT it is VERY sticky. Something low-tack would be ideal.
 

etrump

Well-known member
I would say humidity would cause problems with such tight tolerances. Once you get the prototype working you could always mill out of plastic, plexi or whatever.

Sweet!
 

yongfei

New member
I use a wood called "Paduk" for the body. The wood store said it should be quite stable. Also, I will perform "annual health check-up" and use shims to fine tune it. The birch plywood plates could develop an uneveness problem. But for a $50 camera, it should serve me well ;-)
 

Guy Mancuso

Administrator, Instructor
If it works really good than down the road you can maybe mill one out of plexiglass once you have all the tolerances setup and such. Fun project

Please keep us all updated
 

PeterA

Well-known member
The best material as far as stablity goes is that white stuff plastic stuff that they make bread boards out of. Router fences are often made of the same stuff - Rockler sells them. It is dimensionally stable and also easy to machine. Use machine screws with pre drilled pilot holes and threads, counter sunk in order to maximise rigidity. You can also try using medium density fibre board - as this is even cheaper and just as stable - standard practise in jig making. However - you will find thatthe tolerances for this type of jig - wont allow the type of exactitude required.

by the time you have deconstructed the elements of a basic tech camera analysed the quality of the materials and gone through a few iterations of a cad shopped copy - you will probably decide that buying a TC from Alpa is cheap.

Fun though!
 

yongfei

New member
I just went outside and tested it. The concept works and it is a lot of fun than using a standard Alpa! I took 3x pictures each time, which is very good:)

This is the result stitched from 3 cfv pictures. Now all I need is to do some fine tuning. As you can see, it has some minor lens shift from left to right. It needs to be a straight line.

 

Don Libby

Well-known member
Not a bad image at all considering your using a couple pieces of wood to attach the back and lens together. It'll be interesting to see just what the finish version willbe able to produce.

Don
 
J

jjlphoto

Guest
Your choice of the plywood for parts of it make sense, it minimizes expansion/contraction. The darker wood? Is that mahogany? Tool & die/casting patten makers use mahogany for patterns because it is one of the most stable woods available.

I use shim stock from the local hobby shop that caters to RC airplane builders. K&S brand, package #258 has .001, .002, .003, .005 sheets of brass. The .001 almost feels as thin as metallic wrapping paper.
 

Geoff

Well-known member
The wood you are using is Padouk, and is a good stable wood for this. Ebony and mahogany are also stable.

Corian (used for countertops) is available in big solid pieces as well, easily milled and glues well and strong together. Imagine the camera in solid white! Or the color of your choice!

For shims, I think Sinar makes the alum shim strips (already cut for their back) in alum strips. You could probably either use these, or cut them. They come in pre-assembled packets of several together, which I gather you peel off.

Great project. Keep going.
 

yongfei

New member
Thank you all for the valuable advice, especially the Sinar shim idea! Actually I have a spare Eyelike shim frame at hand. I will use it as a last resort if necessary (because it is not reversable). Last weekend, I already got some aluminum plates from Hobby Lobby. Ready to make some fine adjustment this week.

I am also building an Alpa TC style mini camera right now. If you like this shift camera, you will LOVE that new mini camera. I already cut the body out of Kiev 88. If the idea works, maybe the price of Kiev 88 will go up :) Still waiting for some parts to arrive. Will post pictures and ask more questions later.
 
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