I'm not sure if Joe went with this one - but this is what I suggested to him a few months ago. I purchased the larger version. Admittedly, it is a bit pricey but it performs well (especially with the dimmer). Here is what I mentioned to Joe at the time: You may want to consider a Spike-A Flat fielder light box. They have a version for up to 12" scopes for $230 or a version that will work with scopes up to 16" for $350. Here is a link to it: http://www.spike-a.com/flatfielders/?gclid=Cj0KEQjwyIyqBRD4janGs5e67IsBEiQAo... It uses edge lit LEDs to give even illumination (to 1%). They also sell a USB controlled dimmer that you can add ($120) to give more brightness levels and it should help with repeatability. http://www.spike-a.com/USBDimmer/ I purchased their 16" light box for my 14" Edge HD a little while ago - but I've been too busy to really put it through it's paces yet. Clear skies, Dale. On Fri, Sep 25, 2015 at 2:28 PM, Ed <utnatsedj1@xmission.com> wrote:
Dave,
I trust you have googled a phrase like 'flat field light box' which yields a wide range of home-made versions.
Rather than a white reflecting surface, you might consider white Opal glass acting as a diffuser of transmitted light.
I gather the intent is to provide a uniform light intensity coming from all portions of the surface seen by the telescope. If that is correct, how uniform must if be? Within a 1/3 f/stop variation or more uniform than that?
Ed Stimpson
---------------------------- Quoting Dave Gary <davegary@me.com>:
For those that image?what type of flat-field setup do you have? Did you
purchase the setup or did you build your own flat-field box? What type of light source do you use? If anyone has instructions on how to build a simple flat-field light box any information (pictures would be nice) would be greatly appreciated. Make the descriptions simple. Something that someone who nearly failed shop class (really, I almost did) could understand. Failing that, give me all the technical low-down and I?ll get the wife to help me out so that it actually works when the project is completed.
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