saiph

Hey guys.

Since I've received a few requests on this, I'm posting a few pictures describing the "what"s and "how"s on the afocal-photo use of 2 well known prime tele objectives / lenses.

Real stuff pictures by saiph_ro - Photobucket

I hope at least some of you will find these pics interesting and useful.

come on people, it's not like it hasn't been done few dozens times before...

i tried that already and i have to tell you, it works great!

now, sure, depending on your specific focal ratio, you get better or worse images, but you can't ask for more from an old lens; and by "old" i'm not being disrespectful, i only mean that the glass is made by old recepies, and there's no special correction for visual use, not at current standards at least - it's not what it was initially designed for.

Here:

Real stuff :: Visual Tair picture by saiph_ro - Photobucket

my Tair works great as a grab & go, but its 300/4.5 comes nowhere near the C80 ED which produces sublime views of almost anything (limited to its aperture, of course). the barlow lens cell can be attached directly to the diagonal mirror and get wider true field of view. three or four eyepieces are more than enough.

too bad it's quite considerably heavy and can't be used as a finder for my Alter M603 on EQ5. but even so, the soviets intuitively knew what their tele lens might look like and made it bulky and sturdy, so you can use it for almost anything from visual, to prime, to afocal photo (btw, the sun and moon look so nice, and eclipses are much easier to frame, even with a barlow lens cell inserted in a specially designed adapter for dslr photo).

by the way, when you are talking about converting tele lenses to anything else, it's all about adapters - don't live home without them, and think of any possible combination before going to the lathe workshop with your sketches. use the M42/1 thread to attach any other piece you might want. i sincerely don't recommend plastic/PVC improvisations or worse (duct tape), if you don't want to be disappointed from first shot.

all in all, converting tele photo lenses for visual observations is lots of fun, you get a compact package that can yield in anything you want (bird watching, wild-life, neighbor spying, night time surveillance, wide-field astrophoto, moon- or sunsets / rises, eclipses, landscapes), provided the right adapter/filter is used.

good luck and clear skies!