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Pages: 1 | 2 | (show all) blueman Vendor Blue Sky Accessories Reged: 07/20/07 Loc: California Re: EL Panel uniformity [Re: blueman]       #5203876 - 05/03/12 02:07 PM Attachment (40 downloads) Edit   Reply   Quote Quick Reply   Here is a shot of the box. Blueman Post Extras:       blueman Vendor Blue Sky Accessories Reged: 07/20/07 Loc: California Re: EL Panel uniformity [Re: blueman]       #5203878 - 05/03/12 02:09 PM Attachment (29 downloads) Edit   Reply   Quote Quick Reply   Another showing the rheostat to control the brightess. Blueman Post Extras:       blueman Vendor Blue Sky Accessories Reged: 07/20/07 Loc: California Re: EL Panel uniformity [Re: blueman]       #5203884 - 05/03/12 02:10 PM Attachment (31 downloads) Edit   Reply   Quote Quick Reply   Finally, one showing the box lit up, full brightness. You are looking at the projection screen mentioned in the diagram, made from Stencil frosted plastic sheets, about the thickness of a thick sheet of paper. You can see the light is very uniform across the whole circle. This brightness is enough to take flats with the Ha, OIII and SII filters. I actually turn it down some for OIII and SII. Blueman Post Extras:       blueman Vendor Blue Sky Accessories Reged: 07/20/07 Loc: California Re: EL Panel uniformity [Re: blueman]       #5203901 - 05/03/12 02:17 PM Attachment (25 downloads) Edit   Reply   Quote Quick Reply   Last one, showing low brightness level. Believe it or not, this is bright enough to take luminance flats with my ML8300 camera at about 4 seconds. I usually have it set just a little brighter for this, so the flats are 3 seconds. Blueman Post Extras:       PGW Steve Pooh-Bah Reged: 10/03/06 Loc: Winnipeg, Canada Re: EL Panel uniformity [Re: blueman]       #5204142 - 05/03/12 04:13 PM Edit   Reply   Quote Quick Reply   I've got a Gerd Neumann Aurora panel and it is very uniform. The problem is the brightness, way too much for my LRGB even at F10. It's good for my NB stuff however. They say on the site you can vary the input voltage to control the brightness, but 6 volts wouldn't excite the foil. When I tried 9 volts it lit up, but was a bit blotchy. The manufacturer says to use sheets of paper to dim the display, but the only paper big enough is of lower quality and is kind of blotchy. Not to mention the logistics of keeping a bunch of sheets of paper around and factor in dew and such. I have to make it to a plastic place and get some white plastic to do that chore instead. I wish manufacturers would supply these things with variable supply and solve the known problems. Post Extras:       rainycityastro sage Reged: 03/29/10 Loc: Seattle, WA Re: EL Panel uniformity [Re: PGW Steve]       #5204221 - 05/03/12 04:55 PM Edit   Reply   Quote Quick Reply   Ditto on the Gerd Neumann Panel. Very uniform but bright. It also flickers so if you use a very short exposure, you will see uneven exposure. The best solution appears to be a white plastic or thin styrofoam cut to shape over the panel. But I am worried that this will make the output less uniform. Post Extras:       blueman Vendor Blue Sky Accessories Reged: 07/20/07 Loc: California Re: EL Panel uniformity [Re: PGW Steve]       #5204354 - 05/03/12 06:11 PM Edit   Reply   Quote Quick Reply   My pannel will light up with just 2v and will achieve full brightness with 12v. At 2v it is barely glowing and it just brightens up until you get to 12v or even 13.8vdc from my power supply. I just put the rheostat on the ground wire for the 12v input to the inverter that actually fires up the pannel. Not sure why your pannel will not light up on lower voltages. But, you can go down and buy some sign plastic that will cut down the light. Or use Vellium paper or Stencil plastic sheets, each ar available in 8x10". Blueman Quote: I've got a Gerd Neumann Aurora panel and it is very uniform. The problem is the brightness, way too much for my LRGB even at F10. It's good for my NB stuff however. They say on the site you can vary the input voltage to control the brightness, but 6 volts wouldn't excite the foil. When I tried 9 volts it lit up, but was a bit blotchy. The manufacturer says to use sheets of paper to dim the display, but the only paper big enough is of lower quality and is kind of blotchy. Not to mention the logistics of keeping a bunch of sheets of paper around and factor in dew and such. I have to make it to a plastic place and get some white plastic to do that chore instead. I wish manufacturers would supply these things with variable supply and solve the known problems. Post Extras:       JoseBorrero Carpal Tunnel Reged: 09/04/09 Loc: MI Re: EL Panel uniformity [Re: blueman]       #5227476 - 05/17/12 09:44 PM Edit   Reply   Quote Quick Reply   Thanks for light up my questions. I got an alnitak flat-man directly from the owner but just for a while. I works super nice! my goal is to make my own for a fraction of the cost. I got an EL Panel from a store I'll not mention and test it. But it seems not bright enough. The rheostat idea is super cool,that's on my plans. My design will be "framed" picture style, I guess is more easy to store and carry everywhere. For now, I'm thinking to buy from glowhut or ebay and let see. Post Extras:       JoseBorrero Carpal Tunnel Reged: 09/04/09 Loc: MI Re: EL Panel uniformity [Re: JoseBorrero]       #5251138 - 06/01/12 09:46 PM Attachment (22 downloads) Edit   Reply   Quote Quick Reply   Finally after checking here and there got all parts and assemble it. Here's a pic. Now my EL panel shows some un-uniformity as described at the beginning. Now, How I applied a rheostat here? Post Extras:       blueman Vendor Blue Sky Accessories Reged: 07/20/07 Loc: California Re: EL Panel uniformity [Re: JoseBorrero]       #5251329 - 06/01/12 11:56 PM Edit   Reply   Quote Quick Reply   The rheostat can be installed on the input side of the power converter. If you have a 12v adapter, place in in the ground wire, between the power source and the power supply for the pannel. Blueman Post Extras:       morten super member Reged: 07/22/08 Loc: Denmark Re: EL Panel uniformity [Re: blueman]       #5252209 - 06/02/12 03:12 PM Edit   Reply   Quote Quick Reply   Honestly Is this really a problem, doesn't the defocus take care of it. Advice. Take a series of images with the panel in one orientation, and flat calibrate them with flats with the panel rotated 90 degrees, My guess is that you will see perfect flat calibrated images. M Post Extras:       blueman Vendor Blue Sky Accessories Reged: 07/20/07 Loc: California Re: EL Panel uniformity [Re: morten]       #5252274 - 06/02/12 04:03 PM Edit   Reply   Quote Quick Reply   The Rheostat is used to control the brightness of the panel. If you do not have one, then you are using a very bright setting that is good for Narrow Band filters, but too bright for most LRGB flats. This is especially true if you have a shutter that requires a 2-3 second flat to keep from having shutter shaddows. Blueman Post Extras:       JoseBorrero Carpal Tunnel Reged: 09/04/09 Loc: MI Re: EL Panel uniformity [Re: blueman]       #5252354 - 06/02/12 05:18 PM Edit   Reply   Quote Quick Reply   Got it! but before this, I need to replace the power supply,at the beginning of the thread frostpaw mention that he solve it by replacing the power supply, but he doesn't specify which. Post Extras:       Tori sage Reged: 01/10/12 Loc: Somerville, MA/Warren, NH Re: EL Panel uniformity [Re: JoseBorrero]       #5415026 - 09/11/12 11:36 AM Attachment (19 downloads) Edit   Reply   Quote Quick Reply   For those of you with the non-uniform panels, I have a question: How are your flats working out? I too bought a Gerd Neumann Aurora Flatfield Foil and it's blotchy in a grid-like pattern, see the attached pic. Before I go through the effort of finding translucent plastic panels and building a box for this thing in an effort to make the light even, should I bother? Should I just return it? Or will it work fine as-is without trying to make the light more uniform? I thought the whole idea of this was to be a uniform light source, so I'm quite disappointed it's not. Post Extras:       blueman Vendor Blue Sky Accessories Reged: 07/20/07 Loc: California Re: EL Panel uniformity [Re: Tori]       #5415080 - 09/11/12 12:07 PM Edit   Reply   Quote Quick Reply   The use of diffuser sheets will eliminate the non-uniformity. But,I will admit my panel was not as non-uniform as yours. Still, mounted in a box with diffuser sheets should take care of it. Blueman Quote: For those of you with the non-uniform panels, I have a question: How are your flats working out? I too bought a Gerd Neumann Aurora Flatfield Foil and it's blotchy in a grid-like pattern, see the attached pic. Before I go through the effort of finding translucent plastic panels and building a box for this thing in an effort to make the light even, should I bother? Should I just return it? Or will it work fine as-is without trying to make the light more uniform? I thought the whole idea of this was to be a uniform light source, so I'm quite disappointed it's not. Post Extras:       Konihlav Pooh-Bah Reged: 03/05/09 Re: EL Panel uniformity [Re: blueman]       #5415127 - 09/11/12 12:31 PM Edit   Reply   Quote Quick Reply   I do not see such a pattern on mine (also have one of the Gerd Neumanns while I also have 3 other no-name brands that are pinkish, but not such a notable grid at all). hope more ppl shed some light on it Post Extras:       rainycityastro sage Reged: 03/29/10 Loc: Seattle, WA Re: EL Panel uniformity [Re: Konihlav]       #5415766 - 09/11/12 05:27 PM Edit   Reply   Quote Quick Reply   I dont have a grid pattern on mine either. (Gerd Neumann panel). But how long was the exposure on your camera when you took the above picture? Anything shorter than about 1/10 sec produces flicker in my experience. I use parchment/vellum paper to diffuse mine and to cut some light so that my exposures can be a nice 2 secs or so to eliminate flickering from the panel light source. Post Extras:       Frostpaw super member Reged: 05/17/07 Loc: Seattle, Washington, USA Re: EL Panel uniformity [Re: rainycityastro]       #5415837 - 09/11/12 06:09 PM Edit   Reply   Quote Quick Reply   I don't have a way to do a genuine scientific comparison. A scientific comparison would be to compare flats taken with my non-uniform EL panel against flats taken against a known uniform source. Unfortunately I don't have the known uniform source. I have noticed that if I shoot flats using the T-shirt method I get enough light leakage through the focuser that my flats are non uniform. This pretty much means that T-shirt flats won't do the trick for comparison. Here's one possible test: Show say 50 flats with your EL panel in one orientation, then rotate your EL panel 90 degrees and shoot 50 flats. Once you've done that, stack the first 50 flats into set A and the second 50 flats into set B. Now subtract sets B from set A and look at the difference. If you can see a difference then you know that the non uniformity will show up in your astrophotos. What do you think? Clear skies, -Geoffrey Post Extras:       Alph Pooh-Bah Reged: 11/23/06 Loc: Melmac Re: EL Panel uniformity [Re: Frostpaw]       #5416034 - 09/11/12 08:00 PM Edit   Reply   Quote Quick Reply   Quote: What do you think? How about drawing contour lines based on ADU values in Matlab? Post Extras:       John Wunderlin Vendor - Spike-a Focusing Mask Reged: 10/01/04 Loc: Mineral Point, Wi Re: EL Panel uniformity [Re: Frostpaw]       #5417147 - 09/12/12 11:52 AM Edit   Reply   Quote Quick Reply   Quote: Show say 50 flats with your EL panel in one orientation, then rotate your EL panel 90 degrees and shoot 50 flats. Once you've done that, stack the first 50 flats into set A and the second 50 flats into set B. Now subtract sets B from set A and look at the difference. If you can see a difference then you know that the non uniformity will show up in your astrophotos. I think that would work well. I suspect the non-uniformity will not affect your flats significantly since the panel itself is not in focus at the end of your telescope. Since it's so far out of focus, the pattern you see should be blurred and it will likely work just fine- give it a try! Post Extras:       Pages: 1 | 2 | (show all)

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