Ideal exposure time w/DSLR?


#1

So, after going through the sheer hell of trying to find the camera gain and readout noise for my D5200, I find myself stumped.

In the area where I’m supposed to input my gain values, there aren’t ISO settings, there are binning settings (1x1, 2x2 etc). How does this work for DSLR users? I’ve tried to puzzle this out through the manual and forums and haven’t found a good answer. What do I put in these boxes?

Thanks…


#2

The binning boxes change to ISO when the Nikon camera is selected.


#3

Fair enough, but I meant in the equipment manager dialogue…


#4

Your camera only supports 1x1 binning so just enter data there.


#5

Okay, that’ll work. Thanks


#6

Okay, so for my Nikon D5200, I’ve got a readout noise of 2.0 e-, and a camera gain of 0,56 e-/ADU, which is based on the gain at “unity ISO” of a little over ISO200.

First, do those numbers make sense, and how do I get SGP to calculate ideal exposure time? I’ve tried opening some old FITS files and running HFR on them, but nothing displays in the ideal exposure field in the image statistics. Am I missing a step?


#7

I honestly don’t know if those numbers make sense. I suppose you could look up similar cameras for Canon or the like and see if you find values near the same range.

You need to enter the gain value for the 1x1 binning plus readout noise. Then you need to take an image with the camera… usually 3-5 min is good. We don’t currently support ideal exposure times for images taken in the past (not much point).


#8

Okay, fair enough. Since we’re socked in here in Baltimore, I’m playing with settings and was trying to use an old image just to test. I’ll give it a go next time the weather cooperates. Thanks again.


#9

as a dslr user myself (Canon) I cant say i have ever added anything in the gain values in my profiles as it just didn’t seem relevant for a dslr.
I just set exposure length and iso values in the sequence…seems to work just fine so im not sure setting them in the 1x1 binning is that essential if your using a dslr??


#10

I’m doing the same thing, and have been able to very successfully image using SGP’s basic features, but now I’m looking at using some of the more advanced features like plate-solving and such.

You’re right, this is absolutely not essential, but for convenience, SGP can take those data values about your camera and calculate the ideal exposure time for your target. It’s more of a “nice to have” than something that’s essential.


#11

I have never been able to get the ideal exposure time for my D5100. I also entered the camera gain and readout noise but tried with current images. I’ve posted about this a couple times but never could get it to work. When I asked if anyone else could get their Nikon to provide the Ideal Exposure Time - I didn’t get any replies. Pse post again if you can get yours to work.


#12

I found some great resources for figuring your numbers. I’ll see if I can post them for you later today.

I think the Ideal exposure time only works when you’re actually imaging, not on stored photos.


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