Small glass, big glass
An interesting thread came up in Flickr TechTalk on digiscoping.
Digiscoping
Basically the concept of digiscoping is adapting a camera to use a spotting scope. You can see this as a variant of doing telescope astrophotography (where you connect a digital camera back or a pocket digital camera to a telescope). Or perhaps it came from the old Eagle Eye OpticZooms that people used to screw into the filter mounts of their pocket digital point and shoots: most notably the infamous swivel-bodied Nikon Collpix 4500 and the Olympus C-*0*0Z series. (I have a friend into astrophotography. The fact that his Olympus C-2020Z was a great camera for digiscoping factored into his purchase and hobby.)
In any case, digiscoping is most commonly used 
Riverstone Townhomes, Mountain View, California
Nikon D70, Nikkor 70-200mm f/2.8G VR, Gitzo 1228LVL tripod, RRS BH-55 ballhead
1/800 sec @ f/9, iso 200, 200mm (300mm)
Riverstone Townhomes, Mountain View, California
Nikon D70, Nikkor 70-200mm f/2.8G VR, Gitzo 1228LVL tripod, RRS BH-55 ballhead
3 exposures @ f/9, iso 200, 200mm (300mm)
All these photos have been highly sharpened. Now you might be think these exposure times are short and the apertures are small, but you have to remember the moon is extremely bright: it is a white surface reflecting the sun! Also, the first photo is a crop.
The biggest big-name promoter of digiscoping is Leica. It makes sense because they make the cat’s meow of APO spotting scopes as well as sell a digiscoping kit for cameras like the Leica D-LUX 2 or the Panasonic Lumix DMC-LX1 (essentially the same camera). They have some photos on their site which might give an idea of the typical subject matter and the quality loss of digiscoping.
(I don’t know if it relevant, but the D-LUX 2 is a pocket camera with a 16:9 (2/3″ style sensor, a 35mm frame would be 8/3″ in this metric).
A lot of astrophotographers do use dSLRs for stuff similar to digiscoping (as mentioned above). This explains the short-lived but uber-cool Canon EOS 20Da.
Big telephoto
Whenever someone mentions a big telephoto (like in the TechTalk thread), they bring up a picture of the legendary Canon 1200mm f/5.6 L USM lens. It’s that big lens you see in every Canon EOS lens photo
Now since Paul has corrected me, I am surprised that people talk about this lens but nobody gives a nod to the 1200mm-1700mm f/5.6-8s P ED IF Nikkor.
This stuff is just to drool over. They’re both by special order only (I’m told that the Canon 1200mm was discontinued last year) and only movie studios, spy agencies and sport magazines can afford them. Canon and Nikon wheel this glass out for trade shows in order to measure penis size. Sort of like guessing who’ll make the biggest LCD at the latest consumer electronics show.
Bringing this back to digiscoping, people have done digiscoping with even these lenses: video digiscoping. Counting the multiplying effect of a 1/3″ sensor and adding a 2x teleconverter, you have a 35mm equivalent of 17280mm!
June 24th, 2006 at 11:59 am
Frank Jr. points out an interesting article on digiscoping. I think my guesses are in line with their conclusions, but read for yourself.
June 25th, 2006 at 4:28 pm
Mike Johnston coincidentally mentioned a bird rig from a digiscoping page. From the looks of it, that’s not a digiscoping rig though.
June 26th, 2006 at 4:06 pm
Nikon Sport Optics has a section devoted to digiscoping. On interesting thing is they show a setup that leverages the WiFi features of the Coolpix P1 (and P3).
July 15th, 2006 at 4:31 pm
[...] In tests, painting a lens white doesn’t even create more than a couple degrees difference for a 35mm telephoto lens after an hour of shooting in the Death Valley sun. One or two degree difference isn’t going to make any difference optically for even the largest 35mm telephotos, or with the wave motor action, or whether the rubber parts melt. [...]