Swillis

Thanks for all the replies, very useful. My next question was going to be about the different field flatteners, but it sounds like the Starzonia one would be the way to go. Also great to know there are several mounting options, which since happy-kat is using the original rings could always be implemented down the line if required. I like the diffraction spikes from a newt, but I'm not a fan of them from camera lenses. However, a used Samyang 135 is also on the possible list (maybe with a step down ring on the front to remove the spikes) but for a canon fit those appear to be as rare as hens teeth 2nd hand. But I guess that's a good sign as no one wants to get rid of them... Don't suppose anyone has experience of the Samyang and the 50ed??

Hi all, I'm wanting to upgrade my optics (from a Canon 75-300mm lens🤣), and have seen a few people have been using the Evoguide 50ED as an imaging scope. I'm not looking to upgrade immediately as since the clocks went back it gets dark too late for me now👶. There are a few other options I'm considering, but had a few questions about this first. This would be for use with a Canon600D on a star adventurer. 1) What is the effective focal length when using the field flattener? 2) Does this work well with a DSLR? I believe some of the examples I have seen are using a DSLR. 3) How secure are the mounting rings supplied with the scope once a DSLR is attached to the back? Would it be worth looking at a more secure mounting system? Maybe something where the DSLR can be supported also? I'd also be interested in any other general comments regarding the scope. Thanks for reading Simon

If you run the SA through the app (if it's the 2i) then you can set a number of exposures and also set it to turn off at the end. Not sure if that helps much if your using an ASIair

You were asking for a 'simple' deep sky kit, so I would recommend a star adventurer (or similar) and if you have room in your budget go for a samyang 135mm lens to go with your DSLR. The 72ED will be close to the weight limit of the mount, and the longer focal length will be more demanding on a good polar alignment. This may get very frustrating when your getting started, so I would recommend to keep it simple as there is lots and lots to learn.

The lens may not be perfect, but the best gear to get started with would probably be what you have. As mentioned above add a star tracker and off you go! There is plenty to learn and more cash to invest down the line, but using as much gear that you already have will give you time to learn the basics and let you decide what route you want to go down. If your not expecting amazing results at least the pressure will be off using that lens.

Hi, whilst you waiting for someone who knows what their talking about to arrive... The horsehead is much dimmer than Orion. So I imagine that 35min? (1.25h - 40min) would not be enough. I had I think nearly 3 hours of data and could barely see it (although with much worse optics). Could be that with the larger scope your getting closer to the limit of the equipment, and with the longer focal length it will be more demanding on a good polar alignment. Have you tried keeping all the subs? You can specify only the top xx% get stacked, and Siril will show you a graph of all the subs so you can guage the quality/variation across your session. If you've using a script, set cwd to process and search sequences. If you select r_pp_lights****, you should then be able to specify your parameters for stacking. (I remembered correctly that your using Siril? Sorry if not) Sure someone else will be along promptly...

What ever the budget you should spend as much as possible on the mount. Probably you are going to need the pro. The pro is the same as the standard version, but with the L-bracket and counter weight bar, which you are going to want for imaging DSOs to enable you to balance properly. I have the SA 2i pro and use a DSLR with 75-300mm lens you mentioned. And the mount performs well, the issues are with the lens. As has been mentioned previously you will also want a sturdy tripod. I have the SW one, which does the job asked of it.

I have that lens (and use it for AP) and alacant is right! However if you already own the lens then it may fit your requirements (££) as you get started, but you will soon want to upgrade to something/anything more suitable.

Thanks @vlaiv I was just writing that you can explain it much better than me, when your reply popped up. Also that I picked those pointers from you in the first place.

I'm by no means an expert at this, but have a couple of pointers I have picked up in my short time on here which may help. You said you are using the same set of flats for both sessions? I think this is generally not the way to go as dust can shift between sessions, but also you have added a Barlow which will change the optical path quite significantly. Also, it has been recommended on these forums that darks should not be used for canon DSLRs. Firstly, the temperature cannot be matched to the lights, but canons do some dark subtraction (even with that setting turned off), using a strip of masked off pixels down one edge. Also you didn't say if you used bias frames? So, flats for each session without removing the camera from the scope. Don't use darks but do use bias frames. Happy to be corrected about this by someone more experienced!

Hi, I acquired an astro modified 600D recently (upgrading from a stock 350D) and thought I would share the results. I had to wait a few weeks to get some clear skies, but last week was so good I got out 5 nights and got about 7.5 hours of data. 60s subs, ISO800, with a canon 75-300mm lens (@135mm), on a star adventurer. Stacked in Siril with 20-30 flats for each session, + 30 bias frames (reused for each). Post processing also in Siril. Any constructive criticism welcome... Thanks for looking

Electrical tape is your friend (or masking tape, but it doesn't stick so well). Same for the focus.

I think going up to the WO71 was a good idea, the star shapes look much better. Maybe it was your lens which was the problem with the star shapes previously. Zoom lenses are not great for AP, maybe there are some good ones out there but I have all sorts of weird star shapes with mine. I agree, I does look a bit blue. What are you processing in? In Siril you can do photometric colour calibration, which works brilliantly. Great work 👍

That's looking great for a first attempt! Well done 👍 I think anything I had to say has already been said. You should be able to get up to 60sec with that setup. I have a canon 75-300 lens which is notorious for zoom and focus slippage, but nothing a bit of masking or electrical tape can't solve, just make sure your focus is still good after applying. Also recommend giving Siril a look.

If you haven't already, the Samyang 135 thread is a good read. Imaging with the Samyang 135mm f2 https://stargazerslounge.com/topic/333381-imaging-with-the-samyang-135mm-f2/ As suggested above you should be ok to mount the camera onto the Dec bracket and should be able to achieve good results with this. But you may find you can achieve better balance mounting via a lens collar. There are a few suggestions in the thread. Enjoy, it looks like a fantastic lens!

Not much use now, but can you put graduations on either side of the part you are rotating? You would then have some sort of reference to get close to where it was. Assuming you note down the 'angke' from the first night.

I started out a similar way using what I have with a DSLR and lens (350d and 75-300mm lens) and invested in a star adventurer. The lens may not be ideal, but you can certainly start your journey that way and upgrade down the line once you have learnt setting up the mount, which will be more forgiving at shorter focal lengths. Take a look at the Samyang 135mm thread there are lots of great images with wider field of views. Good luck and enjoy!

Some great images on here. Here's mine. Orion, flame and horsehead nebulas taken on the 4th, 5th and 7th Jan (Bottle 5). About 3hrs of 30sec exposures (threw away 1hour) taken with a Canon 350d, 75-300mm lens @160mm on a star adventurer 2i. Stacked with flats and bias and processed in Siril. Had some strange vertical coloured banding, which was removed in Siril before stacking.

Thanks for all the advice @alacant, I've finally had chance to finish reprocessing this and its looking better now. HH is definitely clearer now. The debanding worked well before stacking, but it didn't cope with the Orion nebula well as there were dark vertical bands above and below it but another round of debanding on the stacked image appeared to sort that out. The manual processing was easier than I thought, and will use it again in the future. Thanks again!

Haha, hadn't noticed the original post date 🤣

Rotating by multiples of 90deg should be fine and not result in loss (pixels are square after all). Anything other than 90 and the software has to make a guess at what the pixel value should be. Presumably stacking software has to do this to some extent when rotating images? Happy to be corrected if I'm wrong, this is based on experience of a piece of equipment at work.

I'll pass this on to support my funding application 😅

@alacant thanks for all the tips. I have started looking into using Siril manually so hopefully better results will be on their way. Was that image using the snapshot I posted? Goes to show how valuable experience is in processing. I tried using per sub background extraction. Is this usually a good idea? @Astro Noodles yes, I am pleased with it 👍 Thanks

Hi, Thanks for the nice comments. @alacant sorry if my description wasn't clear, I used the bias frames for bias and dark. I think this is what was recommended for Canon DSLRs? Although I could have misunderstood. I will try the banding reduction in Siril, but might be a few days before I get chance to have a go. Also 500 subs takes a long time to stack. I don't have guiding so don't think I can dither? Although I probably have a fair amount of 'natural' dither from a fairly poor polar alignment due to no direct line of sight to Polaris. @Sterrenland it's great when these objects start to come out of the dark. The reaction from my wife when she saw the stacked image on the computer was 'its amazing what you can see that from our garden'. @RoloFanatic they are from the way the aperture closes is a camera lens. The 'classic' 4 spikes are from the secondary mirror supports on a newtonian reflector. @Astro Noodles it think it was the 4,5,7th Jan. That run of decent night's after all the cloud. No mods just stock. @Elp yes liking the wide field, might go a bit wider next time. I guess that's why the samyang 135 is so popular, and I'm very tempted to invest in one. Thanks again

Here is a snapshot of the autostretched image showing the coloured bands on the image. Happy to upload any other files if anyone thinks they would be useful in diagnosing the problem. Thanks