Flats and rotators

Is it possible yet to preprogram a series of flats, where SGP will command the rotator to move to proper angle before starting the flats for that target? Right now I have to tell SGP to move the rotator before the flats for each target, so if I’m taking flats for, say, five different targets, I pretty much have to sit at the keyboard the whole time. Can it be automated?


1 Like

It is possible, but not in a great way… meaning that SGPro must have access to plate solving to do it right now… obviously not ideal unless you have a mechanized flat panel. We have this on our list for 4.0, but I am still not 100% sure how to expose it to the user without creating a confusing experience. I’ll need to think about it a bit. Right now I am leaning toward event options that allow a mechanical angle to be set prior to execution. The choices would be any number between 0 and 359, but also a list of targets that contain light frames where choosing one would use the mechanical angle that corresponds to that target’s sky angle.

1 Like

Ken, thanks for looking into this. If the second option would pull the mechanical angle (and maybe the filters also) straight from the lights in the same sequence, so that the user doesn’t have to enter it, that would be fantastic. That eliminates yet another source of user error, which I always appreciate since I can break pretty much anything I touch. :slight_smile:

I may be an idiot but as the flats are to eliminate sensor dust and dust close the focal plane the rotation angle is irrelevant but for lopsided vignetting issues and central obstructions, it does make sense: which I why I swore off complicated optics and stuck with refractors and a clean objective. I use a Pyxis rotator during acquisition and typically shoot sky flats the next day without changing the rotation angle but preserving the focus for each filter at acquisition time. Of course Pixinsight spoils me taking care of that during calibration with the bias and darks.

@astrovienna: I use an Alnitak Flip Flat and a NiteCrawler WR 25/35 RotatorFocuser and my workflow is like this: Slew and center Target, take Lights then Flats with same rotation angle, Slew and center/rotate the next target and again lights and flats. when everything is set up properly I can sleep whole night its all automatic. regards from vienna ; )

drcr: I image with a C11, and the dew shield has an inside diameter of about 14", so my only real option for flats (other than sky flats) is a large flat panel. As far as I know, there’s no way that can be operated by SGP.* If it could, I could basically do it the way you do it with your Flip Flat, which would be great.

  • BTW, a solution that includes terms like “RaspberryPi” or “Arduino” wouldn’t work for me because as I understand it the former is a dessert and the latter is related to those critters that we find dead on the side of the road in the southern US. :slight_smile:

:grinning: I use Eagle3 Pro!

Me too :slight_smile: I actually lived not far from PrimaLuceLab in Italy. They make solid products.

Just checking back in on this. Is SGP4 now able to automatically read (or permit the user to manually enter) the mechanical rotator angle, so that we don’t have to platesolve before each set of flats?

I just made a list of all the targets I need flats for, and I’m looking at a couple hours of babysitting my setup to get through all these. (Yes, I’ve been neglecting my flat-taking duties!)

A related question: how do I know what mechanical rotator angle to use for flats? Right now, I set up my filenames so that SGP automatically writes that angle into them, so I just read that angle from the file names. But I’d prefer to shoot flats in advance. How can I know what angle to use?