Minolta dimage as prime focus camera.

[mill (Martin)]

I started a couple of weeks ago with modifying my minolta dimage 7i.
Man what a pain in the you know what.
The lens is supposedly non removable but i got every lens element out starting from the front.
One by one the element groups came out with great difficulty and i had to check everytime if the camera was still working.
When i got to the second last assy i broke one ribbon cable and you didn't wanted to sit next to me when that happened.
Checked the camera again if still working pfooeee!!! it still worked.
Then another ribbon cable snapped and after this one the camera stopped working.
That cable was connected to an optocoupler (need to resolder that one).
Alas for the last lens i had to disassemble the whole camera
One tip for anyone who wants to try it , do not touch the power board, man that was a nice tingle trough the hand.
Now i am on my way to reassemble the thing and yes another tip, Just don't try to modify an fixed lens dslr.

Had to get another assembly because the soldering didnt work


Today my luck turned around.
I did it!!!!!! whoohoo
The engineers at Minolta told me that there was no way to modify the 7i to do prime photography.
Had removed all the lens elements untill i had only the bare ccd chip left.
It didn't work The camera didn't even start up.
Then after some hard thinking i thought that if i take the lenses out of the last element cell and only leave the focus motor and the optocoupler in, it should work.
Just finished putting the camera together and switched it on.
Pointing at a light i had a very bright pic so on to the 10" dob, wacked it in, and could focus on an distant tree, made a pic and behold, sharp as hell, the only thing is that the pics come out a bit bleuish (might need an uv filter).
So i have an cheap camera for prime focus now and the best thing is that i have proved some engineers wrong.

Now if only someone knows what the flat piece of glass is on top of the ccd.

[Dennis]

Wow Mill, 10 out of 10 for innovation and 20 out of 10 for having the guts to do this!

I suspect the flat piece of glass serves 2 functions:

• An IR block filter to prevent IR reaching the CCD sensor
• A physical barrier to protect the delicate surface and components of the CCD sensor.

I have a Minolta DiMage 7hi on which the battery case has gone kaput, making it difficult to operate, as I have to manually press the battery cover to hold the batteries in whilst also taking a photo. I paid $1900 for this 5 Mega Pixel beauty when it first came out around Xmas 2001 I think?

Cheers

Dennis

[mill (Martin)]

Hi Dennis.
I use an external powersupply and batteries.
You could make an clasp over the battery lid that goes under the battery compartment.
Here is an photo made prime focus.

[bojan]

Hi Mill,
how big is CCD chip?

[mill (Martin)]

Hi Bojan the chip is 2/3".
And $#%^#&# still no clear night to try it out

[mill (Martin)]

Took a pic today at prime focus on my 70mm refractor.
Not sharp because i did it by hand.
The weather is still bad.

[bojan]

Frustrating, isn't it?
I am also waiting for couple of hours of starry sky to try my new equatorial for wide-angle photos....

[Glenhuon (Bill)]

Just about to pull apart my webcam and try a similar thing. Glad its not as expensive as the Minolta, would have to double the dose on my blood pressure pills.

[mill (Martin)]

Originally Posted by bojan

Frustrating, isn't it?
I am also waiting for couple of hours of starry sky to try my new equatorial for wide-angle photos....

I wished it was just for one hour, would make me happy