Swillis

Thanks @vlaiv for the description. That makes sense.

I took a look through the lens with the stepdown ring on and I can see the effect described above So convinced this was the cause, I did a bit of a test the other night, single image with and without the stepdown ring. The image shows one star from the top left (upper images) and one star from the bottom right (lower images) The effect appears different in each corner, but the stepdown ring doesn't appear to be the cause. I should have tested the lens at f2.8, so the aperture was similar but that would have meant removing everything as my mounting bracket obscures the aperture ring. (Maybe one for the next test) I guess Vlaiv might be on the right track with something closer to the sensor. If the effect was caused by a hair would this restrict it to one side of the image rather than all the edges? Could it be something with the construction of the camera? Thanks again Simon

Thanks, could it be the step down ring that's causing it then? I will have to see if it happens again. I have checked the lens and camera, and can't see a stray hairs sticking anywhere. I reprocessed the data and only cropped the very edge out this time There are a few stars at the bottom which have a strong vertical spike, and two fainter spikes in a cross. Thanks again Simon

Thanks for all your replies. The image was cropped more on the bottom and left, so might explain this. I will have to go back a check the uncropped image. If only my original framing of the target was better... But I will check the back of the lens just in case. This was one thing I considered, but I believe others are using similar stepdown rings, but could be using smaller sensors. I will see how it goes next time. It was doing very well in deed, I am very pleased with it. Thanks Simon

Hi, I got out for three nights in a row with with my (new to me) Samyang135 (+600d on SA2i). All went well and I got just over 2hours of 60sec subs. Stacked and processed in Siril. After processing I noticed a couple of the brightest stars (near the edge) have odd diffraction spikes. I was using a 49mm stepdown ring so was not expecting any spikes at all. The lens itself was set at F2 The issue appears that it may be mainly near the edges but hard to tell as the brightest starts are at the edge. Whole image for inspection, but needs some better processing (something to do while it's so cloudy I guess) Thanks Simon

Great work and dedication. I agree with Clarkey, a tracking mount will enable you to get longer exposures and therefore more signal. The star adventurer or similar will easily be able to cope with the lens you have and those you have suggested. Going to 135mm without a star tracker will reduce your exposure time even further. Probably to the 1-2sec range. The astro classifieds section on here (you need a certain number of posts to get access) is a great source of second hand astro kit. I got my modded DSLR from there, and recently got a Samyang 135 but just waiting for a clear night... Keep it up and don't be afraid to ask any questions you have. The folks on here are very knowledgeable and very keen to help

I highlighted the relevent section and then selected 'quote selection' You can also quite a whole post, with the button at the bottom of the post you want to quote you can also @ a specific person @Dark Adaptation DSO astrophotography usually uses multiple long exposures >30sec (upto several minutes) these are then stacked in software and then edited further to bring out the detail. Without a motorised mount you will probably have to limit yourself to relatively short exposures before star trailing becomes apparent (check out nebulaphotos on youtube, who has some great videos using a static tripod). At your focal length this may be <1sec. It would be an option to consider a wide angle lens to get started with. If your interested in planetary, then you would be taking millisecond exposures using a video which can be done without tracking as the object moves through the field of view. Software can the extract the best frames to use for stacking. (disclaimer, I have no experience of planetary AP, and relatively little for DSOs!)

Is there anything in particular you are mostly interested in imaging? DSO or planetary/lunar? As mentioned you will probably be looking at a used DSLR for that budget, not sure what a used planetary camera comes in at. What is the scope and mount you are intending to use? Others would be in a better position to comment on their suitability. On the software side, there is different software for DSO or planetary. +1 for Siril, it's a great bit of software. There is a bit of a learning curve (as with everything) but there are some good tutorials out there to help, and SGL is a great place to ask those 'stupid' questions (there are no stupid questions) good luck with your journey

I got this from Amazon. https://www.amazon.co.uk/dp/B072F8T5FH?ref=ppx_pop_mob_ap_share It appears to work well with a few sheets of paper to dim the screen. I have seen others recommend this or similar on SGL.

I have seen this before with my DSLR. Not sure what caused it, but it doesn't always appear. I used the deband option in Siril, and (de)select the horizontal/vertical tick box. It worked well and the banding was more pronounced than on your image.

If you get the pro kit, which you will need to balance properly, the ball head may just add an extra point of flexibility into the setup. But it would give you flexibility in terms framing your target, and for a wide field, lightweight setup such as this may be ok?? I had forgotten to mention plate solving. This is something fairly high up on my list to add. I took several hours of images of the heart nebula only to find it was in the bottom left corner of the image. 🙃 @ollypenrice I think a lot of people find DSLRs as the 'easier' route into AP as they don't need anything extra other than an intervalometer to run them, and as a beginner the options (and cost) can be a little bewildering. If you have a DSLR then that is one less thing to learn (and budget for), so it becomes easier from that point of view and you can always build on what you have. The equation changes quite a bit if you don't have a DSLR, and then maybe you are a little more inclined to make the right choice and go the astrocam route. Add in an ASIair and and it sounds like it becomes a relatively painless, quick and reliable process, not to mention plate solving. If only I had the budget to start this way... @lankywolf I assume you don't already own a DSLR since you are considering buying one?

Looks like you have a pretty good plan for starting with. As has been said above all or most of those items would likely be with you for a long time even after upgrading to a larger scope and mount that would be a nice portable setup. One thing to add to the list might be a Bhatinov mask to help with focus on the Samyang. Finding dim targets through the viewfinder can be a little frustrating at times. I'm sure your experience in star hopping will be useful, and you can always start with the easiest to find targets. I find that the live view is only really useful for focusing, as I can see much more through the viewfinder. If your worried about not being able to contort yourself into the right position I have seen a right angled adapter for the viewfinder (don't know what you call it) which may help. I'm very happy with the SW SA2i, and it suits me just fine so far. One day I will look to upgrade, the one main thing missing is the second motor. Not necessarily for the goto function (althought that would be useful) but I can see that I would want to start guiding at some point and I would only be able to guide in the one axis currently. On the question of DSLR Vs astrocam as mentioned above astrocams will outperform DSLRs (not that I have any experience, that's likely a while down the road for me). Personally a DSLR was an easy route into AP, its something I'm already familiar with and didn't require any further equipment/ software to learn. At the start with some much to learn, keep it simple. Also with an astrocam you need to download the image to a laptop/pc to see the image, which would mean a very slow process of lining up your target, so you would need a guidescope/finderscope of some description to go this route. One other thought is to consider how comfortable you will be with polar alignment. This will require crouching down to look up through the polar scope, there are some polar alignment aids out there (which I don't have experience of), but I think they would all need a laptop. Others may be able to help with this more. Good luck with YOUR journey. Simon

@woldsman I think the astrodynium ring system has a mount for an EAF. https://astrodymium.com/products/astrodymium-ring-system-with-zwo-eaf-adapter-for-samyang-rokinon-135mm-f-2-lens Not sure if anyone has experience with this or not? I don't have one myself, don't even have a Samyang 135 (yet)! Good luck with finding something that works for you Simon

Also... I have a 600d and use ISO 800. Which is recommended by these two sites, https://astrophotography.app/EOS.php http://dslr-astrophotography.com/iso-values-canon-cameras/

Good start and you've got lots of good pointers there. I would stick to that focal length with that lens or not much further, as you will notice the chromatic aberration gets very bad (you can see it when focusing). My first (and so far only) attempt at the heart nebula ended up with the nebula in the bottom corner 🙈 so you've done a good job getting it in frame.

You're very quickly away from houses up there so should be a few spots about. Unfortunately looking south would be over the town and all the lights I lived in Binfield for a while, but before I got into astro. There is a house with a brick (probably disused) observatory in the garden...

Welcome to SGL and Bracknell! I'm in Bracknell myself. Depends where in Bracknell you are/how far you want to travel. I've never gone mobile myself but there are a good few clear(ish) views in Swinley forest where the trees have been cleared. Somewhere near ///oiled.parts.global (lookup on what3words). If you've only got binoculars then easy to move from spot to spot.

I do the washing up and clear up after the kids! Then maybe watch something on TV if there is time before packing up and bed! All very rock and roll🤘

An image of your setup may help others diagnose the issue? And possibly rule out something simple...

There was another thread recently discussing the merits of a field rotator, or not. Good luck on your journey into AP!

Thanks @tompato that looks useful @alacant yes that is exactly what I meant. Will edit above

Thanks @alacant, it's difficult to know what lenses are good for AP. That one you linked doesn't ship to the UK, but there are ones which do. I assume most adapters would mean that infinity focus cannot be reached? I will have to look for some examples on astrobin, but not looking to make a purchase straight away and I still like the sound of the 50ed thanks Simon

Yes @ollypenrice your correct. Sorry prob poor choice of words. I meant since it is sold/marketed as a guide scope rather than an imaging scope. So wanted to know more about it and what would be required to use it for imaging.

Thanks @ollypenrice, the post was to get a bit more info about the 50ed since it is a guide scope rather than an imaging scope. I have not quite made up my mind on which way to go, but ultimately (given time and budget) there could be a space for both the 50ed and the Samyang.

Thanks again all @tompato that is an expensive flattener... But thanks for the heads up on the offer. @happy-kat I think that pushes me towards a 3d printed mounting option as suggested above, or the WO 50mm guide rings I have seen suggested in another thread (it may have been your thread). @LaurenceT I forgot I had seen you post about the Samyang previously. I have almost been excited a couple of times when a Sony one comes up for sale... Cheers Simon