Jump to content


Photo

Did Questar ever make photographic solar filters?

  • Please log in to reply
6 replies to this topic

#1 RichA

RichA

    Mariner 2

  • *****
  • Posts: 220
  • Joined: 03 Jun 2010
  • Loc: Toronto, Canada

Posted 09 November 2013 - 07:59 PM

I tried using an off-axis unit on a Q-7 but the image of the sun was far too bright. It was like the kind of filters Thousand Oaks made for photography. The brightness was uniform so I doubt it was deterioration of any kind, no pinholes.

#2 ColoHank

ColoHank

    Vanguard

  • *****
  • Posts: 2295
  • Joined: 07 Jun 2007
  • Loc: western Colorado

Posted 09 November 2013 - 09:00 PM

My Questar off-axis solar filter yields very pleasing orange images. Definitely not too bright.

What shutter speed are you using?

#3 Les

Les

    Viking 1

  • *****
  • Posts: 888
  • Joined: 22 Apr 2006
  • Loc: Maryland

Posted 10 November 2013 - 10:02 AM

I don't see anything on the Company 7 site for white light work. If you are doing eyepiece photography, maybe adding a polarizing filter or Moon filter will help.

Actually most photographic filters pass more light not less, hence the prohibition against viewing directly through a photographic solar filter.

If you are handy, you might try making your own aperture mask out of Baader Solar film. I have used a Solar film filter for a Televue 85 on my Q50th and find it delivers all the resolution I get from my Questar filter, although the sun's disk appears white instead of yellow. Actually, that is a help for my old eyes as it enhances contrast.

It does seem odd that you can't photograph something that you can comfortably view visually.

#4 nytecam

nytecam

    Voyager 1

  • *****
  • Posts: 11432
  • Joined: 20 Aug 2005
  • Loc: London UK

Posted 10 November 2013 - 03:21 PM

Don't use Polaroid or acetate (theatre) gells - although in combo they may appear dark to the eye, they TRANSMIT IR/heat virtually unimpeded ! ! :<(

#5 Les

Les

    Viking 1

  • *****
  • Posts: 888
  • Joined: 22 Apr 2006
  • Loc: Maryland

Posted 10 November 2013 - 05:08 PM

I certainly wasn't suggesting using eyepiece filters WITHOUT a solar objective filter in place. But the mylar solar filters work well and are used by many.

#6 Billydee

Billydee

    Viking 1

  • *****
  • Posts: 671
  • Joined: 23 Jan 2008
  • Loc: Winter Haven, FL

Posted 10 November 2013 - 10:07 PM

RichA,

Questar makes a Variable Polarizer Filter for the Questar 3.5 or for the Questar 7 Axial Port (PN19276). The filter costs $453.00 (2008 price list). This would be the way to go for photo work. You should call Jim R at Questar and find out what the max % of transparency is. I would guess that you could use it in addtion to the OTA solar filter.

They also have a 30% polarizer filter that screws to the bottom of the Brandon EPs or the Camera Coupling Set that is part of the 10 piece filter set (PN19235)(set price was $276 in 2008).

Bill

#7 RichA

RichA

    Mariner 2

  • *****
  • Posts: 220
  • Joined: 03 Jun 2010
  • Loc: Toronto, Canada

Posted 22 November 2013 - 12:47 AM

Actually, I'm not trying to do photography. I've seen an off-axis Q7 filter that yielded images FAR too bright to be used visually, so it reminded me of photographic solar filters from other manufacturers. I wanted to know if it was made purposely this way since it didn't appear faded or damaged in any way.






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics