A while ago,I asked if my 70-200 F 2.8 could be used for astrophotography,as I had made a few attempts,but with so much glass in the lens I got reflections.Some of you suggested 'step-down adaptors' to eliminate this problem and thus be able to use this fine lens.
Here is a few of the ones I found on ebay,there is plenty similar.
http://cgi.ebay.com.au/77mm-52mm-77-...tn%3D4%26po%3D
and
http://cgi.ebay.com.au/77-72-67-62-5...I%26otn%3D4%26
Some even suggested a piece of cardboard with a hole in it.I think I might like to get a step down,has anyone here used one similar to these ebay offerings.One goes straight from 77-to-52 mm,the other has a range,do I need such a range for what I plan to do?As astronomy photography is something I seem to be less and less off,just wondering which item I should get for the task.
Any pointers?thanks Chris