Rodd

I wish I could polar align that well. I use a RAPA scope that claims it is pretty accurate. But when phd2 calculates PA, I haven’t been under 5 arcsec but once, at 2.3. Usually it warns me it could be better.

I find I have to do that even with my mount when imaging the planets or the Moon. Kind of frustrating

Ahh. I assumed all mounts track. I guess that’s not true.

How do you track without stars?

I had similar issues-a deluge almost washed away my observatory. I keep my power converters in a cooler beneath the tripod. Like a fool I did not think to place the drain plug on the downslope side, and I left it open! Naturally, the cooler filled with water and sediment and ruined my power converters. The observatory roll-off tracks were buried in mud. No fun imaging in Southern CT.

Regarding filter cycling. I don’t think there would be much difference in my case because I collect allot of data. At least 2 nights per channel. So for each channel my target progresses from about 30 degrees to an hour (sometimes 2) past the meridian. So each channel has data from the various declinations—just at different times. I check PA nightly, but often I make no adjustments

I have nog tried other TV software. I thought it might be due to old darks, but new ones are no different. I guess I could try maxim DL. Good idea.

I fouynd an alternatlyt registered SII stack that I used Windsor sigma clipping to register. Itr was smaller in dimensions, but teh same scale. I guess I must have registered to a cropped master. Dont remember. Seems to have worked. Thanks! C11 .7x ASI 1600 about 13 hours SHO

I found an alternate stack registered with Windsor sigma clipping that doesn’t have the grid. But the FOV is smaller. I think I must have cropped out the right hand area and registered to a cropped stack as the ha, SII snd oiii combine well. thd other issue I have is my amp glow does not calibrate out. Others don’t have this issue. It is only apparent in 300 sec subs (NB). I took new darks recently to see if the darks were the problem, but the same glow is visible. The amp glow is supposed to calibrate out. The best answer is to get a 2600, but I can’t

Out of luck. I checked and only have the registered SII subs and they all have the grid pattern.

No. Only on SII subs

I’ll have to see if I still have the original subs. I usually delete subs once I register and keep the registered subs. I guess I can reregister the registered subs but I only saw this this time. All other channels were collected over the same time and my PA was the same. I typically register all subs to the same sub.

I use PI. I have not seen this before or since. I use either Windsor sigma clipping or linear fit stacking. These are the 2 out of about 10 the software indicates are best. Does it mean there was rotation of the camera or tube or some other part of the system?

Does anyone have any idea what cuased the grid pattern visible in the lower right hand corner? Its in the SII stack. Very odd. Only had this issue once. The prominence of the lines makes nme think it is not one or two subs-but all of tghe SII subs. Rodd

This a particularilly fiendish fellow, no? Perhaps a bit on the cartoonish side (think Pink Floyd The Wall movie).

I started this while waiting for my target to rise. It may seem ironic that there could be slim pickings for Ha targets at this time of year, but I have shot most of them and many others are not suitable for the FOV I am using. I fret over traget selection, because completing an image for me requires significant dedication due to the sky. At .79 "/pix, seeing is critical, so even the darkest, cloudless nights can be a wash. Seeing was good this night, the stack had a linear FWHM of about 2.0, with at least half the subs coming in below 2.0. After the Moon set, luminance subs were coming in at 2.2". There is only about 3.75 hours, so not complete by any means; but I posted at Bin 1 anyway as the level of noise is not too bad. The bright star artifact reminds me that I simply must find a way to get my hands on a 2600 sensor. TOA 130 with .99x flattener and ASI 1600. Ha: 40 300 sec.

Adding ha to the red channel is easy in PI using pixel math. You just have to know the method.

Yes but there is a big difference between an Ha stack and a red stack. If you remove all but Ha from a red stack, it does not equal an Ha stack. For one thing, in my sky my red exposures are 1-2 minutes and my Ha exposures are 10-20 minutes. Many structures that are made from ha frequencies do not have enough signal in that frequency in a red stack. A good example is Ha regions in galaxies-like m106. One adds ha to galaxies because the red channel doesn’t have enough ha signal to do them justice. One would have to collect way to much red to see the same structures, and they wouldn’t be the same, anyway. You’d have to remove non ha signal to see them. Otherwise, narrow we band filters would be worthless

Hmm. But if you compare a red stack with an Ha stack there are obvious differences. The red filter won’t pick up all Ha. There is an overlap in frequencies, for sure, but they are not equal. Maybe I misinterpreted what you said?

Well, certainly not a glistening gem, but at least it is a pill I can swallow. I foreswore all aggression (unless cropping is considered aggressive). Poor seeing, poor transparency, a full Moon, wind, and shaky guiding conspired to make this a thoroughly tortuous project (inclusive of processing. I will not be revisiting this target to try and improve the image. 17 hours is enough. TOA 130 with .99x flattener with ASI 1600. About 17 hours of Ha, SII, and OIII

Part of it is faintly visible in the stacks. I am hoping to capture lots of lum.

I knew this one wouldn’t be finished, but I have been up for 5 straight days, imaging this target from 2 am to 5:30 am each night. It was torture. But I could not waste the clear sky. It’s just RGB, about 10 hours. I’ll double the RGB and pile on the Lum over the next few months. No tail yet, which I am hoping to catch. I really want to portray this one bin 1, but it will take many nights of good seeing. The red channel was collected in decent seeing. Blue and green not so much. I collected 10 sec subs to improve star color. TOA 130 with .99x flattener and ASI 1600 120 sec and 10 sec subs Bin 1 - it almost makes it

It probably didnt help that I shot most of the Ha during a full Moon, and 1/2 SII during very poor conditions. Still....

I'm not sure I have ever been this dissapointed in one of my images. I just don't understand it. This is the first narrowband image I have completed with the TOA and .99x flattener. I had high hopes. With 17.5 hours, you'd think there was 5. Noise was off the charts, and there is what I believe to be incorrect red dust around the upper and right perimeter. Conditions were very poor when I shot the SII, so maybe that's what it is. I was hesitant to post due to the quality of the image, but I am done with it. If 17.5 hours looks like this, 17.5 x 2 won't look much better. So it is what it is. The problem with adding data would be that all channels are weak; I would need to basically redo the shoot. TOA 130 and .99x flattener/reducer with ASI 1600.. 137 300 sec Ha; 60 m300 sec OIII; 63 300 sec SII. Bin2 Edit-decided to add another version. The first is for lighter screens and the second is for darker screens

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