Shimonu

The point of the flat frame is to measure the uneven light across the sensor. The point is that these frames are then used to remove the dust artifacts you'll have in your picture so you don't have to remove the dust, because you're unlikely to remove all the dust everywhere and keep it clean. What is the result like when you have applied the flat frame?

This looks like a decemt flat frame to me, what are you expecting? It's showing the vignetting and dust particles causing the donuts.

I did it unloaded, thinking it would be easier to feel any backlash. But I suppose binding could occur if the load is different?

I've been working on the backlash on my SW NEQ6 to improve my guiding which I did quite successfully, I got quite stable guiding under 1" which I was very happy with. However as I reached a meridian flip them mount started slewing and suddenly locked up on the DEC-axis. I was surprised as I tested the axis before at home and verified it running fine. The only thing I could think of was the temperature difference or maybe I didn't really run through the whole range of the axis. So does temperature affect the backlash in any significant way? What is a good way to make sure the backlash is as tight as it can get? I read that you should ideally find the tightest spot and adjust the backlash there but is there a good way of doing that? Turn a quarter and repeatedly feel for where it gets tighter and then looser but is it really that noticable? Thanks

I'm looking at configuring Ekos to autofocus on filter change but I'm not understanding this "lock filter" option. It sounds to me like I would choose another filter to focus the one I'm going to use. From the indi library website: But isn't the whole point that the focus point can be different for different filters?

Just watched a bit of Cuiv and saw his video on the filter lottery. Manufacturers do not appear to have good quality control when it comes to the bandpass, sometimes it can be incorrectly offset and you're not getting the correct bandpass. There doesn't appear to be an easy way of finding out either, unless you do what Cuiv did and sent the filter to a lab for testing. I don't know if this is the case for you but I certainly wish I had known that before I bought my new narrowband filters.

Maybe I'll do more research on the UNC, if the springs are what I should fix first then that seems like a minor thing I could live with. I just want to feel that I can at least attach my equipment for a few sessions and get a good baseline before I start doing bigger modifications and taking it apart. I'm sure I'm handy enough and capable but I like getting comfortable and knowing the stuff first. Moving up to 100mm+ aperture refractors just feels too expensive at the moment.

So stepping back and instead of looking at my requirements. Is there a recommended scope if I want something around 600-700 mm focal length and 130-150 mm aperture that is well built, pleasant to use and gives good results out of the box? And let's say the budget goes up to around €1000

Wow! I had never considered the position of the secondary and now that you point it out it looks really far back and strange. This UNC would be much better then? https://www.teleskop-express.de/shop/product_info.php/info/p5881_TS-Optics-6--f-4-UNC-Newtonian-Telescope---Carbon-Tube---made-in-Germany.html It's certainly more expensive but that's less important in my mind if it works well and is more pleasant to use.

I'm currently looking at the TS Optics Photon 150/600. I'll likely ask more about disassembly if I get it, I'm sure it's easier once you have something in front of you to look at. Regarding a carbon fiber tube, are the benefits the reduced weight and not having to refocus with temperature change? I'm wondering if it's really worth essentially double the price.

Is this possible to do with the scope assembled or will it need to be taken apart?

Fantastic help, I feel like I understand the steps of collimation better now and it certainly doesn't feel as daunting. I always put my equipment in the car and go just 5-10 minutes away. Is it crazy to think the collimation would hold if done at home and then going out for a night?

I'm trying to convince myself that I wouldn't be too bothered with collimation of an f/4 newtonian even if it would be my first newtonian. I'm doing my best to read guides and understand the tools that are used but I'm getting somewhat confused. I've seen collimation cap, collimation eyepiece and cheshire. These all seem to be either a long or short tube with a hole in the center and an opening in the side(except for the collimation cap). Could someone please clarify what the differences between these are and how they are used? I'm also seeing some confusing discussion on if the secondary should appear in the center or if it should have an offset, or maybe some shadow should be offset and this appears to be different depending on if it's a "fast" or "slow" scope. Is there a clear guide for how to align the secondary and which references to use? Does the manufacturer provide any collimation information(likely TS Optics in my case)? How good of a collimation can you do at home that will then give you good stars? Some seem to feel that you always need to do a final star test.

That's a really nice version of Andromeda. I hope I can get one that good

Much appreciated. When you say the GPU is fussy, you mean even caliper measurements won't give you any guarantees, I'd likely need to fine tune it? Currently I'm looking at the TS Optics 6" f5. I see you have the f4, did you ever consider the f5? As far as framing goes it doesn't seem like you miss out on any targets. My thinking for the f5 was that the collimation would be easier. As it's my first newton I figured it would be a gentler introduction for me.

Birthday is always a good excuse to treat yourself to some new gear, right? I've had my eyes on a Newton and a 150/750 for AP which seems like a good balance for me. Talking to the owner of astro-art he recommended the Lacerta coma corrector, as I understand it it's a GPU-design? However I'm not quite sure what that means. The alternative would be the somewhat cheaper Baader MPCC Mark III. What are the differences here? I've also thought about the guiding requirements. I'm currently getting around 0.8" - 1.4" and I feel like I would need to improve that as my pixel resolution is going from about 2.2" to 1.3". Am I right in that my guiding error should not greatly exceed my pixel resolution? The options I've seen here is: Upgrade my guide scope to a better quality and maybe higher focal length. Get an off-axis guider. Use my Z73 on top of the newton as a guider. I mostly feel like option 2 and 3 are the most interesting. There's also the possibility that my mount is simply too worn and needs an upgrade or replacement. Otherwise, going from a refractor to reflector I'm thinking I'll have to manage collimation so I know some thumbscrews for the secondary is always encouraged. I have a laser collimator which I'll see if it works for me.

Yes, I'm realizing I don't have the overlay now. I don't understand why it isn't enabled by default? I know I've downloaded the images but then I could just never find how they are actually used. That's certainly going to make it easier.

Oh wow! That's more than sufficient for framing! It's not some plugin or extension you have to download that I've missed? I'll have to check that out!

What about if you want some custom framing that doesn't just match the center position of some object? I recently shot NGC7000 and if you want to get the cygnus wall and the pelican for example, there's not just some point you can slew to, you would have to guess and take a lot of test exposures while slewing aimlessly. I don't feel that the planetarium is very helpful as it doesn't show the nebulae outlines or have any pictures.

The point of flats is to capture the vignetting and dust motes, things that affect the distribution of light on the sensor. It's not expected to be flat, it's supposed to make your image more flat as an end result. How does it look when you use it in your stacking?

That nebulosity in the top-right, or bottom-left in the second picture, looks very interesting. I'm sure it looks spectacular from inside the galaxy.

Did you tighten the lock screw for the focuser? Not that I've ever experienced any slippage though. In my experience I've had to look quite closely at the spikes to find the center, they're not sharp themselves. If you're using the built-in mask I've heard claims that it's not really the best performing mask and I'd say there is some merit to that.

How do you approach the acquisition balance between filters? Do you analyze the target and which colours/gases it consists of and focus your acquisition on filters that should have most signal? My first real target with LRGB mono was the Crescent nebula I experienced that using less blue and luminance for example in the stacking would give me a nicer red. If I included an event amount of data on all filters then I felt the image was almost washed out and white/grey in the nebulosity while I expected it to bring out the nebulosity even more. Perhaps my issue is more of a stacking and post-processing problem but I suppose you could avoid it directly by choosing to balance with the filters.

The calibration frames are not affected by meridian flips but your flats might not be identical between sessions.

APP will figure it out. I think the multi-session option in APP is mostly so you can apply your calibration frames per session.