Saturday, 5 April 2008

A DIY digiscoping adapter bracket for Minolta x20.

In an earlier post I had mentioned my experiments with digiscoping ,combining the "ALDI" spotting scope with the DSC H9. I had to give up as the effort just wasnt worth the images that it produced. however I went on to pick up a bargain camera on ebay for just 12 pounds. A 2 megapixel Konica Minolta X20 with 3x optical zoom. The reason I went for this camera was that it had all its zoom mechanism inside the camera and therefore I could place its objective right against the scope eye piece thereby avoiding vignetting.
The camera arrived in top shape and I`m really pleased with it. I now had to put together an adapter to hold it in place. My earlier adapter made from clamps was not ideal because it had too many moving parts coming loose at akward times. Besides it was heavy too. Thus I had to think up something else which had less joints and was lighter and worked better.
I though and thought and came up with all sorts of complicated ideas , each of which demerits enough to be dismissed. Finally as I was scouring the net for something else I happened across a site which suggested making a camera cable release bracket using aluminium strips. It sounded like that was just the answer to my simple light adapter/bracket.
Even as I bought a 1m long 2mm thick aluminium strip, I had little idea how I was going to make it. However, when all the materials came together it sort of just fell into place. All I needed to do was take advantage of the tripod holes of both camera and scope. Make two holes at either end of a carefully measured out aluminium strip and then bend it into the right angle . Then I would bolt the scope on the removable tripod plate with the strip sitting in between with the screw passing through the hole I made. At the other end I could connect the camera to the strip via its tripod attachment with a bolt of the right size ( I used the head of an old mini tripod).
The x20's objective is not in the centre but is actually in the top left corner and this made it slightly tricky with the placement of the holes.
I had no tools for the job so I punched a hole with a large nail and twisted a large scissors in the small hole and grated it into a larger size.... and hey my adapter/bracket was ready!
he camera when fastened in place rests tight against the eyepiece and is still adjustable by firm little pushes. What I like best is that this adjustment leaves the battery and SD card slot exposed so that I can remove/replace them without having to remove the camera once it is in place. Also such a positioning allows one to turn the eyepiece to adjust the zoom factor. This can be done without removing the camera unlike some designs of adapters.
A disadvantage with aluminium is that it has a tendency to become malleable under the weight of the camera and thus can swing about in position if not held in place tightly. I plan to overcome this by a minor adjustment such as giving the camera a support on the eyepiece so that it cannot be pushed upwards and away from position.
So does it work? unfortunately, when I did it the first time the holes were not in the right place and the camera was not touching the eyepiece of the scope, so i had to make more holes to rectify the errors and by the time I finished the sun was down and I couldnt test the finished product. However I did test the version with the wrong holes and here are are the results:
This one is of a pigeon, (probably the same as my previous post), which
came to my feeder. The focus is not perfect but this was only a test. The vignetting is huge since I havent zoomed in at all.

and these are of a couple of pigeons sitting on a far away roof antenna:
Once again, not really great focus and quite a bit of purple fringing, but still good magnification and scope for improvement.
Just for comparison this is what a camera image 3x zoom of the rooftop would normally look:

and this is if it is zoomed in 15x (Dsc H9):
So, atleast I`m getting clear magnified images, which is the whole purpose of digiscoping. I hope to test it out in field conditions this weekend. Till then watch this space.

No comments:

Post a Comment

Please leave a comment on what you liked or disliked about this post. Any thoughts on technique or improvements are welcome.