Subject: [Tweeters] What equipment?
Date: Jun 30 17:36:58 2009
From: Jim Greaves - lbviman at blackfoot.net


I made comparison of straight (400mm) versus mirror (500mm) on
Chestnut-collared Longspur, and of hawks using scope+digital SLR
(DSLR) versus straight lens (lower power)+DSLR. Sometimes the donuts
are "interesting" if not pleasing, other times...who knows? I liked
straight lens results of the longspur "foray" [a relatively sedate
bird which cooperated when I left to get the mirror for "closer"
looks], but for some subjects I've found the mirror did better on
contrast, when feather detail (for instance) was not important;
others might not like mirror for any subjects due to those issues
Kevin Purcell mentioned; diversity in results is what keeps
photography interesting and fun! Personally, I do NOT recommend
scope+point and shoot OR DSLR (I have used the latter, with mixed
results, some excellent, others not worth the time), and I don't
recommend point-shoot umpteen-x power because they are generally too
small to see the subject sharply (having to wait for CPU analysis
later = just like film!), and they tend to focus where THEY want to
rather than where the shooter is interested... that, and they're just
too slow in response time (advantage of ALL digital is the ability to
keep shooting, before the subject does something "exciting" right on
through that "instant" sometimes to even better than anticipated,
like taking off after feeding, wings spread, water dripping from feet
-- hard to anticipate with any set-up). Here are links to my comparisons:

http://blackfoot.net/~larkwick/ChestnutcollaredLongspur.html
http://blackfoot.net/~larkwick/Merlins.html
http://blackfoot.net/~larkwick/MoreMerlins.html [first shot of
comparison - the scope on tripod+SLR plus greater power obviously
wins!] [but that is due to a dining, relaxed individual, who might
not have spent as long in such repose otherwise]

and, for "proof" of mirror lens' versatility, notice the results on
Red-naped sapsucker, a very cooperative and approachable individual
owing to having been looked at by many people while wintering in that
tree -- second of the 3 species posted below [not much donut to worry
about once one gets that close, and especially if clear sky behind].
Most if not all 400mm to 600mm straight lenses cannot close focus to
12-20 feet [though I did not do that with RNSA - BUT, it's great for
butterflies, snakes, lizards, flowers, spiders, and other crawly
things], but Tamron is STILL known for doing what others don't, won't
or can't -- though Sigma seems to be trying):

http://blackfoot.net/~larkwick/Sapsuckers_Woodpeckers.html

Jim Greaves, Montana -- I hope this is useful to someone out there
[I have no financial interest - other than $$ out and copyrights - in
products named above, or on above-mentioned web pages]