Clarkey

That is really impressive for 90 minutes of data. 👍

Just to add to my earlier comment. To manually dither you can just use the hand controller to move the image in the camera a fraction at a time every few frames. This will get rid of the walking noise. If you have dozens of frames you only need to do it every few minutes. Alternately I would suggest a laptop with some basic control software which can dither for you even without a guider. It will also help with things like focusing and framing.

I'm not sure how you find Gimp, personally I did not really get on with it. I purchased Affinity Photo which I find excellent. At the moment it is 50% off at 24 pounds which is a months rental of PS. Also, the developers seem to be getting on the AP bandwagon and are starting to add useful tools. There are also some macros available from James Ritson which can help.

Slightly better version - slightly better processing (I think).

Thanks for the comment. This was taken using the ASI1600 mono.

Despite my head saying 'forget it', with 3 nights of clear skies forecast I felt I had to image something. Narrowband would have been a better option, but due to available targets from my garden I decided to have a crack at M51. In total I managed 17.5 hours integration, unfortunately a large proportion of this was in the blue channel as I put the wrong filter in my sequence. In addition, on the first night I got my gain setting wrong on the calibration frames and the following night the mirrors were covered in dew by the morning. I ended up having to use one set of calibration frames for all 3 nights. I guess the usual frustrations of AP🤬. Anyway, given all the challenges I am quite pleased with the result. (I know the collimation is out on the RC8 but as yet I have not been brave enough to try an re-align in). Any feedback welcome - especially with regards to the processing as I still have a lot to learn. Thanks for looking. 68 x 3min Lum 59 x 3min R and G 117 x 3min B 30 x 5min Ha Processed in APP and Affinity

Maybe the Iris nebula is like the place in the sea where all the rubbish collects! It's unbelievable the amount of space junk.

You best option will be dithering the images. Even if you don't guide, some software allows dithering (APT and NINA I think do this). If you are just using an intervalometer and saving in the camera, just shift the image by a few pixels every few frames.

I had some similar issues with my flats last night. The previous day with exactly the same set up they were completely fine (I ended up using the previous days flats as nothing had moved and I ran the same image plan for two nights). I have put it down to condensation on the mirrors or camera. It looked similar to this except the centre of my flat was dark. Could this be something similar?

Really nice image. Great colour. Whenever I see this I still struggle to see the monkey though! Definitely one for my 'things to do list'

Looks like dust in the image train on a reducer, flattened or filter. It will be tricky to pick up on calibration frames but it should be removed by flats. You will only notice them on stacked images because they are so faint on a single sub.

You need to move to Penrith for the clear skies and sunshine😉 The delights of F4 imaging. That detail would take me a few hours......

I have a similar issue with my new RC8, although it is not as bad as this. I believe it is due to tilt on the focuser - this effect is exaggerated by using a reducer inserted in the focuser tube. Although the collimation is pretty good, the focuser alignment is definitely wrong on mine. (You can see the offset reflection on a very bright star shown by the mirror reflection being out of line). I put a simple laser collimator in the focuser and this shows the reflective plane of the secondary does not line up with the focuser. Rotating the collimator shows the offset is consistent. I am hoping to get an M90 tilt adjuster to compensate. Unfortunately this is down to focuser being attached to the primary mirror - but very slightly out of alignment. I would wait for some 'expert' opinion on this though. I am new to the RC8 so I might be wrong!

It might be - I got two of a faulty batch of FF / Reducers from SW in the summer so it does happen. However, as the stars seem to be pointing out to the edge of the frame it could be the distance from the FF to the sensor that is slightly out. Difficult to tell in the top right as there are no big stars to look at in detail. Maybe try altering the spacing slightly and see if it improves. Ian

Regarding the cooling question - cool to the same temperature regardless of the external temperature. I normally cool to -20 but in theory it would be possible to go lower. I have my Darks library at -20 so it make sense to keep at this temperature. Below this temperature you will not see much improvement in the amount of noise from the sensor. Having said that, you could try it and see. The only possible benefit of not cooling so much is if you were running a mobile unit from a battery. If it was warm you might want to save power by reducing the cooling current. Not really a problem in Cumbria!

As has already been mentioned, longer subs and much more integration time will really help. But a good start none-the-less. WRT the vignetting, this should be removed by the flats. I assume the stacking has been set up correctlty? I'm not sure of the size of the 533 sensor, but I can use a 1.25 connection on my 1600mm without issue (although this is right at the end of the image train).

That was my thought. Or it sees a GC as one big star. Unfortunately meridian flips are tricky. Using the RC8 the cluster does take quite a bit of the FOV.

Looking for some guidance from the SGL collective. I was trying to image some star clusters the other night due to the full moon. I normally image nebula and galaxies so this was a bit of a 'new' thing for me. I was using ASTAP to platesolve the images as normal, but for some reason it would not solve. I had a number of tries, but it would just not do it. I was wondering, is this a common problem with platesolving software specifically for globular cluster? Is there something in the settings that I could do to help? Any suggestions gratefully received. Ian

As rl states above a bit more detail of what you are looking to image and your kit would help. For around £500 personally I would go down the small refractor route. I image with an Evostar ED80 which has been really good for the money. With hindsight, if I was to change anything I would probably want to have a slightly wider field of view for some of the larger nebulae. You can easily crop a larger image. The other option you have is to buy a camera lens such as the Samyang 135mm everyone seems to use these days. I think keep an eye of ABS and something will probably turn up.

At least it was in focus🤣 But more seriously, we have all done daft things before. If AP was not so frustrating it would be too easy!

Just one set at the end of the night as close to the 'normal' focus as possible.

In theory as long as you don't move the focuser or anything else. For the amount of time Flats take I would do them in situ, but it's not critical. The other benefit of doing them before bringing everything inside is you can take them when it is dark and there is less risk of light getting in your image train - especially if you take dark flats too.

I'm glad you asked. I didn't dare....

I use a tablet with a 'white screen' app for my ED80 and an A4 LED panel for my RC8. It does not quite reach the very edge but it does not appear to affect the flats. You do need to careful not to buy a side lit LED as the brightness is uneven. I think mine, which has variable brightness and is USB powered cost about 30 pounds.

I warn you now, AP is a slippery slope.... I have a modded DSLR (Canon 600D) which takes reasonable images and I do sometimes use it as a OSC. I have not done it yet, but I intend to use it for some planetary and Lunar in the future. However, for DSO's a cooled CMOS or CCD is always going to be better. I have a ZWO 1600mm and filters and the Canon cannot compete. I would still be torn between colour and mono, but I quite like narrowband imaging too so mono was the choice for me. The other big benefit is the use of a darks library which does save time and effort. I would say if you can stretch to it get a dedicated astronomy camera. The one thing a good astronomy camera cannot sort out is the rule of sod. Just different ones!