I'm gonna reply, but not about astrophotography.
I have two mirror lenses, both 500mm f8: Lentar and
Spiratone. the Spiratone is much smaller than the Lentar.
I shoot the Lentar a lot. It is not a good lens, particularly
with regard to contrast. But it _is_ a 500 and it was cheap.
I've found
I would say generally that mirrors are never quite going to perform
like
regular lenses, however if you can provide a stable platform that will
help
considerably.
You know, I've seen this opinion expressed many times. It's a very
common opinion within photographic circles. I've
On Tue, 10 Dec 2002 17:53:28 -0600, Dan Scott wrote:
I suspect bokeh is a not a common topic in Astronomy.
Hmmm. I hadn't thought too much about all of the subjects being at
infinite distance. So, how far away does a star have to _be_ to be
rendered out of focus. :-)
TTYL, DougF KG4LMZ
On Wed, 11 Dec 2002 09:33:08 EST, [EMAIL PROTECTED] wrote:
In my experience [mirror lenses] seem to lack contrast.
Hmmm. I don't really need, that. But I would like a long lens that's
lighter. Refractive 400's and above get a bit heavy.
TTYL, DougF KG4LMZ
Also I think folks with less photographic experience than those
here might be tempted to use the lens hand held - given the low
weight that is a likely possibility.
Gee, I, er, um, will bet that, errr, even some of us here might
possibly, maybe, perhaps do something as, ah, dumb as that...
In my experience [mirror lenses] seem to lack contrast.
Hmmm. I don't really need, that.
I think that catadioptric lenses will always suffer a little
contrast loss, due to the central obstruction of the secondary
mirror. However, in my experience, this varies a lot from mirror
lens design to
So, how far away does a star have to _be_ to be
rendered out of focus. :-)
About 10 or 15 feet... ;-)
Fred
Good one Fred!
Steve Larson
Redondo Beach, California
(There's more than one way to [design] a
cat.)
Fred
(There's more than one way to [design] a cat.)
Good one Fred!
Don't encourage me, Steve - g.
Fred
On Tuesday, December 10, 2002, at 07:54 AM, Doug Franklin wrote:
Howdy, Peter,
On Tue, 10 Dec 2002 04:20:10 EST, [EMAIL PROTECTED] wrote:
I would say generally that mirrors are never quite going to perform
like
regular lenses, however if you can provide a stable platform that
will help
Howdy, Peter,
On Tue, 10 Dec 2002 04:20:10 EST, [EMAIL PROTECTED] wrote:
I would say generally that mirrors are never quite going to perform like
regular lenses, however if you can provide a stable platform that will help
considerably.
You know, I've seen this opinion expressed many
Hanimex used to make a 300mm mirror telephoto lens in screw mount. it
wasn't a very expensive one, but it worked OK. are there any 300mm reflex
lenses out there for K-mount that aren't too expensive? i wouldn't use the
FA* 300 f4.5 to justify the cost of buying one.
Herb...
I had the Hanimex 300mm f5.6 mirror (k-mount) for a short while. It cost
me about 50 Euros. I tested it against the FA*300/f4.5 and a Revuenon
300mm f5.6. The flare of the Hanimex mirror was horrible and made it
almost unusable. I can even send some bw scans, but that would take a
while
Hanimex used to make a 300mm mirror telephoto lens in screw mount. it
wasn't a very expensive one, but it worked OK. are there any 300mm reflex
lenses out there for K-mount that aren't too expensive?
Herb.
Seek out the Sigma 300mm F4.5 Apo (from probably the 80s I suppose) or the
Tamron
Message text written by INTERNET:[EMAIL PROTECTED]
Seek out the Sigma 300mm F4.5 Apo (from probably the 80s I suppose) or the
Tamron SP 350mm F5.6 Cat. Sig for preference - a stoutly built number with
APO glass.
Kind regards
Peter
OK, thanks. i need adequate quality glass, at least for now.
Herb Chong wrote:
OK, thanks. i need adequate quality glass, at least for now. any idea what
the going rate is for one in good condition?
I have an SMCP 400mm f5.6 which I could be persuaded to
part with if you are looking for a quality long lens for
a reasonable cost.
Message text written by INTERNET:[EMAIL PROTECTED]
I have an SMCP 400mm f5.6 which I could be persuaded to
part with if you are looking for a quality long lens for
a reasonable cost. Contact me off-list if you like.
Bill
want reflex for weight and size reasons.
Herb,
I tend to carry my FA * 200/2.8 + 1.4X-L converter. Gives me 300mm
reach and the weight/size is not that bad. That is one of the reasons
I would consider selling my A 400/5.6. Just a thought.
Bruce
Monday, December 9, 2002, 11:25:07 AM, you wrote:
HC Message text written by
Message text written by INTERNET:[EMAIL PROTECTED]
Herb,
I tend to carry my FA * 200/2.8 + 1.4X-L converter. Gives me 300mm
reach and the weight/size is not that bad. That is one of the reasons
I would consider selling my A 400/5.6. Just a thought.
Bruce
i'm thinking of a used converter
There are a number of brands that represent that type. You could check e-bay
they show up occasionally, usually in t-mount so putting a K adapter on one
is not
a big deal. I've seen them new under the Ritz house brand. (I don't
remember the
price but I wasn't even tempted so I guess it must
Message text written by INTERNET:[EMAIL PROTECTED]
I've seen them new under the Ritz house brand. (I don't
remember the price but I wasn't even tempted so I guess it must have been
too much).
Ritz is selling a 500mm f8, but that is too long for me. also, at $129, how
cgood can it possibly be? i
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