Using a lens as a basis for a digiscope? (2 Viewers)

NickAgain · Feb 17, 2004

I hope none of these questions are _too_ stupid. I have dabbled in theroy with telescope building, but it was some time ago. I have used telescopes of the smaller type. I inderstand the relationship between a film placne area and the length of lens needed to provide certain magnification, because I used SLR cameras.

Now suddenly I am using a non SLR digital camera (Oly C750) and I find that the take real tlel shots I do not wory about film plane size and distance, but use the camera as my "eye" and actually take a picture of an eyepiece. I was starting to think about removing the lens of my camera, to use ity as an "SLR" with DIY lens mounts. Do not _ever_ tell my wife <G>

I actually did this with a 50mm lens and a little webcam I have. It gave respecatble magnification, but of course poor shots. The colour was also all wrong, as the webcam's little lens had a red-coloured filter in front of the sensor, I suppose for light balance.

So. I have looked thiough a reasonable pair of Nikon 9 * 25 binoculars (well one half anyway) with the 750 zoomed all the way in. This gave me a small amount of vignetting,with an effective eyepiece dimaeter of about 13mm. It also gave a phenominal magnification! Quality? not sure, as I was hand-holding the entire thing. (No drinkies the previous night, and I could actually see something <G>)

I gather this is 10X (zoom) by 9 X (binocs) to give about the equivalent of a 4500 mm lens. I am therefore looking further <G>

I have also tried a rifle scope. It has a huge eyepiece, but is unfirtunately set up so that your eye is a way from the eyepiece when you get a decent image. This has to do with having to hold the riflle.

I have a reasonable Tokina 50-250 zoom lens..This has an object aperture of 52 mm and would therefore be quite bright at say 5X as a telescope or telephoto setup for a digicam with a power of 5:1..

Jay Turberville · Feb 17, 2004

Last time I looked, the moderators of the digiscoping forum had expressed a desire to keep digiscoping discussions limited to the use of conventional birding scopes. I can't seem to find the "sticky" that stated that policy (I'm probably looking in the wrong place), but I don't recall any notice of a change.

I find these lines of inquiry interesting, so if you send me an email directly, I will be happy to relay some of my experiences with this concept. The technique can work very well. But it definitely does not result in a conventional birding telescope and I'm pretty sure that makes it an innapropriate topic on these forums. If I'm wrong, I'd be happy to tell you more here. But it would probably be best if you simply email me at:

[email protected]

assayer · Feb 17, 2004

Nick,

Jay is the expert, but I have a couple of comments I would like to share with you.

I would be careful about removing the fixed lens from your camera for two reasons: 1.) it will likely void the camera warranty...although this might not concern you, and 2.) it will expose the camera sensor to dust and dirt which can be difficult and risky to clean.

Secondly, since you mentioned telescopes, there is an inexpensive and simple little book put out by Edmund Scientific, "How To Use Your Telescope" No. 9055 that sells for $5.50. The last two pages treat Photography With Your Telescope" and describe with diagrams the four systems for connecting cameras to telescopes. Only one of these uses a camera w/lens, that is an AFOCAL system. If this book is no longer in print, contact me and I will help you get these pages.

I have taken photos using an AFOCAL system that turned out pretty good. However, these photos have not been of birds. AFOCAL systems are a bit Rube Goldberg, awkard. and inflexible.

The other three systems described by the book do not use a lens intended for the camera and all require an adapter which may or may not include internal optics (eyepiece or barlow) depending on the system.

I hope this is of some use.

Regards,

NickAgain · Feb 19, 2004

assayer said:
Nick,

Jay is the expert, but I have a couple of comments I would like to share with you.

I would be careful about removing the fixed lens from your camera for two reasons: 1.) it will likely void the camera warranty...although this might not concern you, and 2.) it will expose the camera sensor to dust and dirt which can be difficult and risky to clean.
------------------------------------------------------------------

Thank you for your reply
My message appears to have been truncated. I was not intending removing my lens from the camera in the end. I was interested in using a tele lens from a 35mm camera as the basis of a scope, using an eyepiece, and was asking about that.

I had a heap of trouble joining this group, then I was logged out when I simply tried to see a new list of messages when I finaly did manage to join,

Now "Steve" has "shouted" inaccurately at me in a reply to my query about what was happening. My message appears to have been cut off. It seems that I should not have posted it anyway????

I can't see any point in hanging around, for all that I may have had useful feedback.

alan_rymer · Feb 19, 2004

NickAgain said:
assayer said:

Nick,

I was not intending removing my lens from the camera in the end. I was interested in using a tele lens from a 35mm camera as the basis of a scope, using an eyepiece, and was asking about that.

Click to expand...

There are people on this group taking pictures with Digital camera's though a 35mm SLR lens with ascope eyepiece attached. It works well. Unfortunatley you have to get used to an upside down reversed image!.
Its easy to try out. Take a plasic cape of aproximatley the right diameter at the open end. Bore a hole the right diameter at the closed end for the eyepiece, tape the large end over the end of the 35mm lens, test how far the scope eyepiece needs to be a way from the lens for Min/Max focusing. Tape it in place and voila, a trick scope!.
HTH

assayer · Feb 19, 2004

Nick,

What Alan is describing is an AFOCAL system and a method for determining the proper distance, between the camera lens and the scope eyepiece, for focus. Although I have no idea what a "plastic cape" could be in this example.

Sorry you've had some problems with BirdFourm. I find it a very good and reliable site; with many knowledegable and helpful members.

Dick

dacol · Feb 19, 2004

NickAgain said:
...Now suddenly I am using a non SLR digital camera (Oly C750) ...
So. I have looked thiough a reasonable pair of Nikon 9 * 25 binoculars (well one half anyway) with the 750 zoomed all the way in. ... I gather this is 10X (zoom) by 9 X (binocs) to give about the equivalent of a 4500 mm lens. I am therefore looking further ...

Nick,

Not quite an aswer to your question but just a remark regarding comparisons with SLR lenses. I also have an Oly c-750. The specifications indicate focal length vary from 6.3 mm to 63 mm and state that its SLR equivalent is 38mm to 380mm. Thus, with a 9X binocular in front, the effective focal length is 9x380 = 3420 mm not 4500 mm .

Dalcio

alan_rymer · Feb 19, 2004

assayer said:
Nick,

What Alan is describing is an AFOCAL system and a method for determining the proper distance, between the camera lens and the scope eyepiece, for focus. Although I have no idea what a "plastic cape" could be in this example.

Sorry you've had some problems with BirdFourm. I find it a very good and reliable site; with many knowledegable and helpful members.

Dick

Dick

Its just my typing

. "plastic cape" should have read "plastic cap" as in the top off a can of aerosol spray deoderant ( Mens Gillette ).
I am using a 200mm lens from my 35mm camera and a 25x eyepiece from a 52mm scope.

Using a lens as a basis for a digiscope? (2 Viewers)

More options

NickAgain

New member

Jay Turberville

Well-known member

assayer

Well-known member

NickAgain

New member

alan_rymer

Well-known member

assayer

Well-known member

dacol

Well-known member

alan_rymer

Well-known member

Similar threads

Users who are viewing this thread