safariranger said:
Hi Gasman, Please also fill me in on how things go for you with this combination. I also have the 20D and want to use it with my Swa ATS 80 HD, but still need to buy the adaptor. Not sure if I am making a mistake by doing this, but am really desparate to start digiscoping.
From South Africa it is not easy to get the necessary adaptors for using the smaller compant digital cameras and this is frustrating and also means a lot of time waiting to get parts sent over from abroad.
If you have success then I may very well just settle with using what I have.
Regards
Robert
Hi
Recently tried experimenting with the Canon 20D on a Kowa 663 hooked up with a 50mm 1.8 lens on a Kowa TSN1 adapter, eyepiece is the new Kowa 20-60 zoom.
It is indeed a challenge, but so far I have found there are three problems:
First, the light reading from the camera hooked up to the scope is inaccurate, generally over exposing by about two stops, possibly even more.
Next the auto focus, well, forget it, this will not function properly through the scope.
Third problem, vignetting creeps in if the aperture is set smaller than f4.
The best approach appears to be working fully manually as even using exposure compensation gives inaccurate metering.
Working like this it would appear the camera can be used on ISO 200, probably even 100, aperture f3.5 or larger and the shutter speed increased to underexpose by 2 stops or more.
Taking a test shot, then reviewing this and checking the histogram will confirm that in spite of the camera readings correct exposure is being achieved. Shooting in Raw you can then check and adjust the exposure on the computer and confirm how close you are to correct settings.
Have attached a couple of snaps; both on ISO 200. T1 using AV priority and according to metering correctly exposed (AV4.0). T2 shot on manual (AV5.0, TV1/50) and seriously underexposed and showing the vignetting.
Not sure if this proves anything, but the possibilities are interesting.
Sidor