Unknown mirror lens, ID needed.

SonicScot · Posted: Sun Feb 03, 2013 10:55 pm Post subject: Unknown mirror lens, ID needed.

I was watching a film from 1995 the other day called Heat, in it Robert De Niro uses a camera with a mirror lens attached, with what looks like a scope. I just wondered if anyone recognised it, all I now is it looks a lot bigger than my 3M-5CA.
(apologies for screen-captures but they were the best I could get)

WolverineX · Posted: Sun Feb 03, 2013 11:33 pm Post subject:

Celestron C90

ManualFocus-G · Expire: 2014-11-24

Looks like some sort of Celestron scope like this one:

http://usedbinoculars.biz/2012/07/13/celestron-c90-catadioptric-maksutov-spotting-telescope-telephoto-lens-eyepiece/

Edit: Beaten to it! Laughing

SonicScot · Posted: Sun Feb 03, 2013 11:41 pm Post subject:

Thanks guys Very Happy

Are they/were they any good?

WolverineX · Posted: Sun Feb 03, 2013 11:46 pm Post subject:

for 1000mm mirror telescope it should be good. i was eyeing this lens on ebay, but current lack of funds prevented me from buying it.
it's smaller & much lighter than russian 1000mm mirror

SonicScot · Posted: Sun Feb 03, 2013 11:48 pm Post subject:

Looking at the modern versions and their prices, I'm guessing not.

danfromm · Joined: 04 Sep 2011 Posts: 576

I had a C-90. Far and away the worst lens I've ever owned. Massive center hot spot with irregular (not circular) shape. Terrible astigmatism; when focused near its close limit on a window screen the vertical or horizontal wires could be made sharp, not both at the same time. Not sharp either, and that shouldn't be a surprise.

Turns out that the lens as delivered (brand new in factory packing) was missing an extension tube needed, Celestron said, for best performance. Celestron took it back, replaced it on warranty. The replacement was the second-worst lens I've ever owned. I never got a shot I'd show in public from either.

Celestron has made some very good photographic objectives, the C-90 isn't one of them.

ForenSeil · Joined: 15 Apr 2011 Posts: 2726 Location: Kiel, Germany.

There were many different Celestron C90 variants with partially different optics (for example 1000mm F11 or 1250mm F14) and builds made over the decades.

You can find some technically very good photos made with "the C90" on Flickr etc. but also many very crappy ones.
I don't know if it depends more on the different versions of the lens, more on the photographers (to focus and expose with an 1000mm+ lens isn't easy!), more on the technique (many people are using compact cameras and shoot through eyepieces) or more on the bad quality control of low-budget Celestron lenses - BUT it is possible to make technically very good photos with it, also in daylight!

The successor of the C90 in the movie is currently available very cheap on Amazon.com http://www.amazon.com/Celestron-52268-C90-Mak-Spotting/dp/B0038QYRDO together with an simple eyepiece.

I had the larger brother Celestron C130 2000mm F15 and I was pleased for the price I paid (less than 150�) but it was much too large more my taste. It was even too large to stay in my living room (my girlfriend nearly killed me Smile

). Here's a pic of the moon made through my window:

The C90 is much smaller though while it should have similar IQ

Celestron also has a high quality "Edge HD" cassegrain series specialised for photography
Look at this beast for example http://www.teleskop-express.de/shop/product_info.php/info/p3262_Celestron-Edge-HD-1400---356-3910mm-Flatfield-Cassegrain-OTA.html Twisted Evil

3910mm F11 Twisted Evil

SonicScot · Posted: Mon Feb 04, 2013 6:35 am Post subject:

Awesome moon shot Shocked

Gotta love the information this place can offer on all manner of equipment, thanks. Cool

ForenSeil · Joined: 15 Apr 2011 Posts: 2726 Location: Kiel, Germany.

SonicScot · Posted: Mon Feb 04, 2013 12:19 pm Post subject:

Wow

danfromm · Joined: 04 Sep 2011 Posts: 576