autofocus scope. (1 Viewer)

I was pondering how to get didgscoped shots in focus with what I've got (see depth of focus post) and wondered if I played about with the autofocus system in the camera, would I be able to make the camera control the scope?
If I put a jack in the side of the camera that can disconnect the internal camera autofocus (when plugged in) and instead make it control a small motor attached to the focussing ring of the scope, would it work if I set the camera to the 'infinity' setting?
I can now hear a few of you asking 'why don't you buy some better gear' to which the simple answer is 'I'm broke'. I reckon the parts cost would be about ~£10 from Maplins.
Just wondered if anyone else had tried this sort of thing before.

colonelboris said:

I was pondering how to get didgscoped shots in focus with what I've got (see depth of focus post) and wondered if I played about with the autofocus system in the camera, would I be able to make the camera control the scope?
If I put a jack in the side of the camera that can disconnect the internal camera autofocus (when plugged in) and instead make it control a small motor attached to the focussing ring of the scope, would it work if I set the camera to the 'infinity' setting?
I can now hear a few of you asking 'why don't you buy some better gear' to which the simple answer is 'I'm broke'. I reckon the parts cost would be about ~£10 from Maplins.
Just wondered if anyone else had tried this sort of thing before.

Click to expand...

The idea sounds great, if it would work, but I have doubts. If you were to set the thing on Infinity, how would it work, the focusing mechanism would have to move to operate the system, just my thoughts of course. Could be worth a fortune if it works, Good luck Ernie

It's just at the ideas stage at the moment due to that whole 'cash' thing.
Maybe it would work better with a switch that rough focusses the scope, then the camera, the scope again and finally the camera on fine focus. That's effectively what I have to do by hand, but with a motor and the cameras auto-focus detection gubbins, that may still be a fair bit quicker and more likely to be in sharp focus.

Now this is a bit of guesswork...
The 'infinity' setting on my camera seems to have no problem with focus on anything more than ~ 12" away. Below that, it tries to focus and works ok. If the camera is pretty much always in focus and I hook it up so that the wires telling the internal lenses to move are hijacked and led to an external motor on the focussing ring of the scope, surely then the scope would be focussed by the camera?
That's assuming that it wouldn't just give up and say that it couldn't focus at all...

The other idea I had was to attach a removable arm to the focussing ring so that you can move the arm only a little and achieve a finer focus more easily than by moving the ring itself.

colonelboris said:

It's just at the ideas stage at the moment due to that whole 'cash' thing.
Maybe it would work better with a switch that rough focusses the scope, then the camera, the scope again and finally the camera on fine focus. That's effectively what I have to do by hand, but with a motor and the cameras auto-focus detection gubbins, that may still be a fair bit quicker and more likely to be in sharp focus.

Now this is a bit of guesswork...
The 'infinity' setting on my camera seems to have no problem with focus on anything more than ~ 12" away. Below that, it tries to focus and works ok. If the camera is pretty much always in focus and I hook it up so that the wires telling the internal lenses to move are hijacked and led to an external motor on the focussing ring of the scope, surely then the scope would be focussed by the camera?
That's assuming that it wouldn't just give up and say that it couldn't focus at all...

The other idea I had was to attach a removable arm to the focussing ring so that you can move the arm only a little and achieve a finer focus more easily than by moving the ring itself.

Click to expand...

I love your thinking, it all sounds very feasable, I hope you achieve your goals, get a cheap secondhand camera to experiment with. Ernie

Next step is to get onto my brother-in-law and see if he fancies a project for his masters in electronics...
I forgot he was doing that until the Mrs just reminded me.

colonelboris said:

Next step is to get onto my brother-in-law and see if he fancies a project for his masters in electronics...
I forgot he was doing that until the Mrs just reminded me.

Click to expand...

Way to go Colonelboris, great idea.

You really will make a fortune with this one.

Thanks, everyone.
Two other things occured to me in the past few days.
1: I taped a thin strip of paper to the focussing ring of my scope with a series of numbered marks on it and another slip of paper to the body of the scope.. I found which numbers corresponded to just going out of focus each way and took a lot of shots inbetween. It appears that all of them are progressively becoming more in focus, but never quite get there, indicating that the view on the screen is not quite what the camera is capturing.
2: A lot of cameras come with an AV adapter that slots into the USB port. This means that you can use any size TV you like to view what your camera is seeing. I may see if it's possible to buy a cheap ortable TV with the correct connection so I can see the image much, much larger than the 1.8" screen allows... Even a 5" battery-powered screen would be a massive improvement in focussing.
I'm still going to have a pop at the scope, though...

Right, the latest idea is...
Using the AV output, I can connect the camera to a laptop (courtesy of work...) and have a live feed of what the camera sees on a 15" screen. A marked improvement on the 2" camera LCD. I'm also going to make a 'fine focus' wheel to attach to the focussing ring. That may take some work, but not too bad, I think.
This means I have to get a TV card (or something similar) for the laptop to read the AV output. A quick look on t'internet reckons about £35.
This means that the limiting factor on the picture quality should be the quality of the optics. The bonus (apart from better focussing) is that it should all be pretty transferable if I get a much better scope and/or camera.
Obviously, not everyone is lucky enough to have been saddled with a laptop that was infected with a grotty virus that left it a shadow of its former self while the supervisor buys a brand new one for his use, but it should work just as well with a cheap portable tv if it has an 'AV in' socket. I think you may also be able to buy cables that go from the camera AV out to a traditional RF in socket, but I'll have to look for that, but it would mean that pretty much any TV could be used.
All sounds a bit cumbersome, but I'm not convinced that the camera I have would be able to focus the scope with the small amount of light coming through the lens. I think it'll be nigh-on impossible to also adjust the camera's programming so that it can reduce the sensitivity of the autofocus. However, I'll still have a word and see what I can do...
Watch this space...!

Couple of thoughts if you get full screen images on the laptop, you should be able to do the printscreen thingy and save them straight to the hard drive on the laptop and it would be fun to do it in a hide so that people could gather round the laptop and see in real time what you have got in the scope.

Mick

Good points. The image quality wouldn't be great from a printscreen as the output from the av isn't all that high as far as I know, but they'd still be nice to have and could also be done in the stab of a button, unlike taking the actual shot itself on the camera where you have to wait for the shutter/ccd to have a pop at it. It's a delay of at least a second on the vivitar I use, so that'd be a good thing to get the odd image from the laptop.
As you say, it'd be nice to let everyone share the images as ell.
One snag, though. All the TV cards I've seen are USB2 and I think the USB ports on the laptop are USB1. There is another port at the back which looks different from the other one, so I'll investigate and see what's doing.
There are some TV cards for about £15 on ebay, so that might well be an excusable expense...
Cheers!

I did a bit of research on USB1 and USB2 for a different reason and and far as I can see USB2 is backwards compatible so should still work albeit slower.

Mick

Ah, but does USB1 still supply power to an accessory? The TV card has no power source other than the port.

I have only got USB1 and it powers my card reader and also my broadband modem but not at the same time alas, I only have 2 sockets on my PC.

Mick

Awesome!
Now to see if it works altogether...

After speaking to my brother-in-law, he thinks it could be done but would be pretty difficult to make sure it works. It looks like the 'through the laptop' idea may have to be employed.
Now to buy a video capture or TV card cheaply...