Re: Re: [APML] Medium format wide field scopes

Loke,

I thank you for your suggestion. As for the light fall-off issue, Peter Ledlie sent me a pic with this condition, and it was relatively straightforward to flat-field. Not as well as Tony Hallas did for the same shot, but I'm not Tony, either :)

Mike

----- Original Message -----

From: lkt

To: astro-photo@seds.org

Sent: Wednesday, March 27, 2002 1:46 PM

Subject: Re: Re: [APML] Medium format wide field scopes

If you cannot find a Traveler, there is also the Tak FSQ106. I have seen a few of these on sale on Astromart for quite a significant discount. These have a flat field and are made to be astrographs, i.e. built in camera rotator, large focuser etc. With some of the other choices, you will have to add a field flattener which might not be available, and for 6x7cm fields, a field flattener is a requirement. It has been reported by some that the FSQ has noticeable light drop off in illumination. As such for very deep exposures, you might have to apply anti-vignetting masks to remove this.

Loke