jm_rim

I'm could not find one specific problem when testing different stacking combinations. However, while assessing my scope I found a massive light leak, which I'm quite sure is causing some of the problems. But if it has affected my flats or light frames (or both) I'm not completely sure of yet. I will try and do some more testing and optimize my scope as...

Hi, I'm fairly new to the processing part, as I first recently have had success with getting useable frames. I have tried to stack both using DSS and APP with a similar outcome. I have attached an overprocessed image where there are clear strange colours. Am I doing something wrong in the stacking process, or I this due to gradient, or are some of the calibration frames to blame? Nikon D5300 Dark, Bias, and Flat

I hope I did. My RA clutch is not working optimally, which one of the things I need to fix. If it is because of the worm gear, can that affect the frames - besides the drift? Or do I have to change it?

I was able to do some testing last night. First, I ensured that no cables could be the cause. Then I polar align using SharpCap, and finally I balanced my mount a little east heavy. I have, again, made a small animation of the first 4 hours from last night. Running east heavy seemed to have help quiet a lot - or is it just me hoping to see an improvement 🙂 The frames are drifting in the RA tracking direction, I this do to polar alignment error? And in the end, I look like the telescope went out of focus (hoping to my autofocus motor today). There is still barbell/elongated stars, which I assume is most likely do to periodic error, as I seem to be a repeating pattern. So I guess that my next step is, to check for backlash and shorten my exposure time, for now. And when there comes a period with bad weather tune my mount.

Going through my setup, I could see that it was almost perfectly balanced. So tonight I will try to test if running it east heavy will help. Going through my setup, I could see that it was almost perfectly balanced. So tonight I will try to test if running it east heavy will help. Else it seems that guiding is properly going to be needed to compensate for these errors - based on your earlier comment @vlaiv

Okay, I have made a small animation of the first 4 hours from the last two nights. The elongation is in the RA direction, but looking closely, it seems to "wobble" in both directions. Could this mean that it is backlash do to the RA being in perfect balance and random swaying back and forth?

Guiding is definitely something I will begin to prioritise higher. I have been looking at Sky-Watchers own GOTO upgrade but also belt drive kits such as the EQStarProEQ5. Hopefully, I will be able to get a guide camera, guide scope, a GOTO upgrade, and the needed accessories for £600-750. I know that with my current setup I am pushing my mount to its limit - I'm hoping to change my scope to a 500mm refractor after the summer. This will at least lower the total weight and make guiding a bit easier/more forgiving. I was thinking of upgrading my mount, but I think I will with that until a can afford one load capacity greater than 20kg.

Is there still are some low clouds - despite all my weather app was promising a completely cloudless night - I will try to go thoroughly through my set-up tonight. To at least rule out the more obvious or visible tings that could be the cause.

It is aligned with RA axis Shoot objects closer to NCP/Polaris - how close? I mostly shoot above 30 DEC (currently between 45-60) I have thought about "tuning" my mount as you describe - just hoped that i could avoid it 😀 I have also thought of upgrading the mount with GOTO, possibly with a belt drive kit, as I can't afford a new mount yet. Would auto-guiding help with minimizing these kinds of errors?

I will try to re-balance the scope again tonight, hopefully it will have an effect yes the direction of movement is the direction the mount is tracking with something loose and knowing the direction of the movement - does that mean i can narrow it down to the RA axis?

Going through my images from the last two clear nights, I see that many of the frames had small barbell shaped stars. The direction of the elongation is following the RA axis. This is not on every frame, in some, the stars are as perfect as I can get them, see the images. My setup: SW EQ5 with RA motor, SW 150PDS, and a Nikon D5300. I don't have auto-guiding (yet) so this is not the problem - only using a single RA motor. My mount is on my balcony - quite protected against the wind - it was -12c to -15c and there was absolutely no wind. So I don't think it is due to "external" factors causing vibrations. I polar aligned using SharpCap and took successful 200sec test shoots, but used 120sec during - just to be safe. Anyone have an idea of what can be the problem - backlash, Periodic Error in the RA, or something else...? And how to fix/minimize it?

Sorry, it is in the RA direction. If it is the RA drive that is sticking, how can this be solved ?

I was shooting IC 348 (RA: 03h 44' 36", Dec: 32º 10' 00") and the image i attached is very cropped in. No guiding (still on my wishlist 😁) No wind and -12º

After many frustrating nights, I'm finally beginning to have some success. However, then going through my images from last night, I noticed that many of the frames had small star trails (I guess), see the image. This is on every 3rd to 6th exposure, in all the others the stars are “perfect”. I polar aligned using SharpCap and took a successful 200sec test shoot, but used 120sec during the night - just to be safe. Can this be do to backlash? My setup, SW EQ5 with RA motor, SW 150PDS, and a Nikon D5300.

I’m using SharpCap with a 750mm and and aps-c sensor with no problems.

Hi, My apologies for asking the same question as many already have. I have done an extensive search on this forum (and others) about DIY modifying a Nikon DSLR. One thing that I can't find the answer to is whether it is possible to use a Baader BCF 1 in a Nikon D5300? I read that some buy a 50x50mm Astronomik L-2 UV+IR Blocking Filter and then cut it themselves. But, the BCF 1 is half the price of the L-2 filter - and no risk of breaking the filter when cutting it. Does anybody know if the Baader BCF 1 can be used in a Nikon D5300 or do I have to get an L-2 and cut it my self? Any advice is appreciated.

I finally had a successful night 😁 wuhuu I managed to get short exposures in Shapcap and could polar align to excellent in 5-10min. I “solved” my Backyard Nikon issue - don’t know how, but it is not just reporting busy after an exposure. I tighten the RA motor extra hard - witched solved one of the tracking issues. I did some test to see how much I could push my setup. On the EQ-5 with a RA motor, a SW explore 150pds with CC, and a Nikon D700, I managed to get good 300sec exposures one 500sec turned out ok... But I had it running all night, with no problems, and would just like to say thanks for all the help and good advice...

I don't have a guide camera - only a RA motor. However, between each frame there is a very small downward shift (not start trails), maybe this can be consider as a kind of dithering? :-)

Yes, I'm using a D700 which have can close the view finder. This is a good question - I started taking the dark frames about a half hour after my last light frame. However, the dark frames keep getting brighter, which, at least in my logic, does not indicate a light leak. If it is a light leak should all the dark not look the same and not gradually get brighter?

After a whole night of (hopefully) successful imaging, I started my early morning by finishing up with calibration frames. But know, after getting all the files into DSS, I noticed that my dark frames look very strange. The first 4 looks fine (though with a circle in the middle), but the rest keeps getting lighter with a circle in the middle (no change in ISO or shutter speed) - which really annoying since the last 21 dark frames cannot be used. Have anyone else experienced this or somebody know what the reason for this might be? Since I'm using a DSLR and the dark frames shall have the same temperature - can I try do take new darks tonight when the temperature is roughly the same as last night? Thanks, Jesper

I will try and have a look at this, thanks 😁

This i will definitely try, thanks. I really don’t understand why it the error occurs. In the fall there was no software issues - just alignment issues 😩

Thanks, I will try to look there. Good to know

This is good to know. But I need to find a way to lower the exposure length, 30s is to long and is making the PA to long when using Sharpcap... I was hoping to go down to 4s (max 8s). Are you using a dslr or a guide camera?

I actually tried PA with Sharpcap using the DSLR for the first time last night. It made it so much easier - although I struggled with having enough visible start, and ended up with having to use 30s exposures which made... But ended with excellent PA and this was using my 150pds + 2x converter... When I finally was done and wanted to test what the max sub length could be - BackyardNikon just said ”busy” every time, with nothing happening no matter how long I waited...