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Just got a Questar 700-very nice lens

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#1 smithkent

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Posted 11 August 2010 - 02:07 PM

Just got back from the latest eclipse in the South Pacific, and was tired of lugging around my C5-which is a super eclipse scope, but still a heavier setup than I'd like for the next eclipse in 2012. I saw a Questar 700 for sale and snapped it up. My preliminary photos show a very nice image sharpness over the entire field. It shoots at f/8 which is just fine. While the focal length is a bit short for the inner corona or prominences, it will be super for a nice full frame corona shot. In my investigations, this lens was made in rather limited quantities- maybe it just never had much advertising so questar didn't continue making them. As a portable eclipse scope I think I found a gem!

Any one else here have experience with the Questar 700?

#2 Larry Geary

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Posted 11 August 2010 - 03:08 PM

I have two, one a bit sharper than the other. The less sharp one was used on two eclipse trips, and produced very nice pictures. Even shooting the diamond ring there was no evidence of internal reflections, unlike a Canon 300mm f/4 L lens I used for a third eclipse, which showed lots of internal reflections from the multiple lens groups. I thought the focal length was ideal in that I was able to get good detail on limb features like prominences and the chromosphere, and still have enough field of view to capture an extensive corona. All this was on 35mm slide film. I would definitely recommend it for eclipses, but you might want to try it on the moon and terrestrial targets with your camera and decide for yourself.

#3 smithkent

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Posted 11 August 2010 - 06:10 PM

Good idea- I'm going to give it a shot when we get to full moon- similar exposure conditions to totality

#4 Larry Geary

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Posted 11 August 2010 - 06:41 PM

But also shoot other phases to check the sharpness and see if it meets your needs.

#5 Rat8bug

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Posted 12 August 2010 - 01:41 AM

The Q700 was one of the best mirror telephotos, based on a 70's review in Modern Photography. At the time, I could not afford one, so I bought the Vivitar Series I 600mm Solid Cat instead. Had a hard time getting one, as the rumor was the CIA was buying 'em up. One can increase FL easy by using a 1.4, 1.7, 2x or so teleconverter. In my case, I chose the Kenko Teleplus Pro 300 1.4x. This TC preserves detail and you only lose a stop in exposure.

http://www.barrie-tao.com/apex127.html

Ciao...Barry






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