How to Make a Flat Frame Panel for Dark Sites (Cheap)
Posted 28 March 2021 - 11:16 AM
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Posted 28 March 2021 - 12:54 PM
Brilliant idea. I'm wondering if the scope is necessary though. could you put a smaller EL panel on the end of a T-adapter and take the exposure with just the camera. I have an 11" SCT and building this to that scale could be prohibitive. I'm just learning astrophotography myself so please no rude comments.
Posted 28 March 2021 - 01:38 PM
I believe that Flats need to be made with the full optical train in place...telescope, correctors, filters, OAG, sensor, etc. Darks can be made with just the camera and a cap to block the light.
- nicedoggie, Michael Covington, bobzeq25 and 3 others like this
Posted 28 March 2021 - 01:45 PM
The electroluminescent panel lots of folks use is powered by the usb from your laptop and costs about 24 usd. Works on apertures up to about 260 mm. Not sure if larger ones are available.
Posted 28 March 2021 - 02:17 PM
Yes, flats need to be made with the full optical train in place so they can compensate for any blockage of light, including dust motes anywhere in the system.
- nicedoggie, bobzeq25 and Benschop like this
Posted 29 March 2021 - 07:17 AM
Nice job, always great to see people making stuff, a tradition in this hobby. Did you use 1/4" or 3/4" plywood, maybe the photos make the thickness look exaggerated. Can you post a few histograms of from your camera?
Posted 29 March 2021 - 07:28 AM
Do you have a link to the panel you bought? Also you said the panel was cuttable/scalable, has anyone actually cut one to size? I would prefer square, and the 10 x10cm is to small.
- Baron von Smoogle likes this
Posted 29 March 2021 - 11:19 AM
Does this put out white light or Blue? Does the color actually make a difference? I thought you had to use a white or very light colored source.
Posted 29 March 2021 - 01:06 PM
So let me answer a couple of questions posed. First, the blue light did create a bit of a problem. When taking flats with a CLS filter, in particular, I was getting zero red signal in the flat frames. So I replaced the blue EL panel with a white one, here:
Now that one does not have the battery pack (because I could reuse the battery pack from the first EL panel I purchased), so you'd need to purchase that, as well.
Posted 29 March 2021 - 08:58 PM
I tried the EL panel but the one I got had a black smudge (bad spot) on the screen and eventually the actuator (on-off) wore out and I never could get the whole thing working again (still tweaking because I can't just throw it out). I hadn't gotten around to mounting it due to the weight issue and material choice for the light block. I replaced it with this: https://www.amazon.c...uct/B07TPS9TQ1.. The USB cord that came with it is long enough to reach to my battery pack which has a USB charge port. I've also used it with a USB phone power pack which is similar to your battery. I do like your idea of the foam to eliminate stray light. May have to create a sleeve for the pad for each of my scopes. Great work.
- AstroAug likes this
Posted 30 March 2021 - 11:48 AM
Excellent idea! I have a new project that will be a great addition to my kit. Thank you for sharing!
Posted 30 March 2021 - 04:26 PM
If the color of the light is not white enough for you, you can filter it with a theatrical gel filter at very low cost. I wrote an article right here on Cloudy Nights something like a year or year and a half ago about that very thing.
Posted 05 April 2021 - 11:55 PM
Easier yet, is to buy "Fairy Lights" from Amazon that have flat watch batteries. You just tape them to a board and create a box out of foam board with a cloth defuser inside. They are much, much lighter than a battery pack and work well.
Posted 09 April 2021 - 05:30 PM
My flat panel came in a cardboard box, nicely held securely with foam packing around the edges. I simply cut out a circle in the middle of the panel (box ) to accomodate my dewshield, cut out a hole over the on-off button and one for the USB power cord then sealed it up like it arrived with postal packing tape. When it is in place and turned on, there is essentially no light leak. Just put it in place, turn it on, take your flats, turn it off and remove. I couldn't be happier with how simple and effective a solution this is.
Posted 17 April 2021 - 04:10 PM
1st, I love it. I'm a do it yourself'er guy.
What problem does all this work solve ?
Seriously, is all of this kind of mock up thing really necessary to get good flats? Are taking flats in this manner necessary.
Like I said, I really love it, I'm just not sure if this is going to be "better" than a simple translucent plastic or tshirt over and embroidery hoop.
Clear Skies !!
Posted 17 April 2021 - 05:14 PM
I gathered that when he said "no light leak" the point was to have something you could use at a star party without disturbing others. Is that the case?