Xplode

8.8 is a little stronger than A4, but the small difference doesn't matter for your use. Go for the A4 stainless...galvvanised is more for when you can't get stainless or you need a lot so there's a large price difference.

Go for either stainless steel or galvanized. I used galvanized threaded rods on a project where stainless got too expensive because of needing 10-12m of M16. https://www.speedyfixings.com/product/m16-stainless-316-a4-threaded-rod/ (A4 Stainless is more corfrosion resistant than A2) https://www.speedyfixings.com/product/m16-8-8-high-tensile-galvanised-threaded-rod/

M12 or larger would be fine, 15-20cm is more than enough and will be totally overengineered

How come people make greats images at 1000mm on tripods? I've imaged lots on tripods myself with a 8" newtonian. Usually the problem when it comes to wind is the mount itself, it will go back and forth on backlash.

To test the resonnance. The sand was added more as a peace of mind thing, i don't think it actually does anything helpfull other than to change the frequency of the resonnance. Most piers are way overengineered. Think about the crappy tripods people put their gear on that still works perfectly....

We filled his pier with sand to stop the ringing when hitting it. The pier has been in use for 2 seasons with a 10 Micron GM2000 doing unguided imaging.

As long as you have a thick baseplate there is really no need for fins. I made a 165cm pier pretty much the same as yours for a friend and he didn't want fins....we found we're not able to even budge it a little. Baseplate 10 or 12mm, collumn is 6 or 8mm. In total the collumn weigh a little over 90kg

The fixed rate for anything up to 1 cubic meter is because most of the cost is actually doing the delivery to you, not the concrete itself. My guess would be the prices on that site is price for the concrete alone so delivery is extra

Could you tell more about your setup? It's not easy to say for sure what the problem is from your images, to more easily tell i think you should take a sequence of subs and stack them, problems will easier show up then. Also do a 2nd sequence where you rotate your camera 180 degrees, this will make it much easier to compare as the FOV will be exactly the same.

Nice image Gav! One of them is definitely a distant edge on galaxy. I found this taken by Hubble

Thank you. It's captured in Spain at a remote observatory, altitude is around 550m

I didn't say small APO's are just for beginners. They are of course very good for wide field, but short FL reflectors for that too, Takahashi Epsilon, Celestron Rasa and a bunch other fast reflectors.

Thanks for the comments They certainly forget that smaller scopes just don't have the resolving power of a larger scope...to get small stars and increase resolution there's no way around a big reflector. Small APO's are nice beginner scopes that allow for mostly problem free astro imaging, that can't be said about the cheaper reflectors out there that often can't keep collimation from one side of the sky to the other.

This is first light from SkyEyE Observatory with our now AG Optical FA14, a 14.5" f5 reflector. Despite the bad collimation and no flats i'm pretty happy with this as first light for the scope. The scope was not collimated before first light as we had to figure out the imaging train first to get correct distance for the extremely short Optec Gemini focuser with only 12.7mm travel. Gear: AG Optical Convergent FA14 14.5" reflector (1855mm/f5) 10 Micron GM2000 Optec Gemini focusing rotator Moravian G3-16200 (pixel scale 0.67") ZWO ASI174MM Mini (OAG) Exposures 18x300s Lum 12x300 R 2x2 12x300 G 2x2 12x300 B 2x2 This was edited in around 10 minutes. To spend more time on it i want some more suitable RGB exposures, 120s 2x2 is way too much signal to get out color in the stars. Click for full resolution

I had a chance to test the ASI174mm Mini tonight, at 3s exposures there weren't a lot of stars in the FOV, in the area around M13 i got 2! With just 2 stars on the large large ASI174mm sensor there would be a big chance of 0 stars on a smaller sensor since they are 1/4 the area or even smaller. I will test more tonight and increase exposures and gain to see if i can catch more stars. I saw no hot pixels at the settings that were used, but they might appear at higher gain.

I'm having a scope being installed in Spain at the moment with 1841mm FL with an off axis guider, to get a larger sensor the ASI174mm was chosen for the task, if it works ok i will know for sure in a few days The scope is a f5 just like yours. I will let you know how it works out.

There's nothing to be afraid of. The protocol for communication between PC and the Autostar is exactly the same, they are based on the LX200 protocol, also others manufacturers have used the same protocol in their mounts. Astro-Physics, Losmandy, 10 Micron and some some Celestron mounts are based on the LX200 protocol. They do of course add more functions to their drivers, but the basics are exactly the same.

They have spread out a little and some of them have raised their orbits, remember i'm seeing them at an angle and not from right under so any satellites with raised orbits will look like they are parallel. Some of them are of course still in a train and at the same hight as can be seen from the brighter trail.

I got an image of the Starlink satellites this evening. It was taken from SkyEyE observatory in Spain (at e-EyE Extremadura) at 22.45-50 CET which is 45min before it gets totally dark. 5min exposure. FOV is 2x2.4° I can see 26 streaks, 25 single satellites and a brighter one consisting of several sattellites, there's also a few satellites that that passed outside the FOV. The galaxy in the middle which noone probably cares about is NGC4457 I might mention that i'm not worried about Starlink creating problems at all for astrophotography, they have a low altitude so they will only be visible during twilight, not high in the sky when it's night.

Firstly the luminace master is a RGB file, did you try to make a syntethic luminance file by stacking the RGB files? Stars are large blobs so all your images are unfortunately out of focus Looking at vignetting/donuts i can also say that your flats aren't fixing all problems perfectly.

How about posting som of your unedited lights, flats, bias and darks some it's easier for people to help at finding the problem? I'm not sure about what could cause the halo, but for the problem with flats not fixing it perfectly my guess would be that the scope just isn't stiff enough so one of the mirrors moves a little bit from the imaging position to the position you take the flats. A pretty large dither should fix problems like this if you dither every 1-3 frames. It can take up a lot of time to dither that often, but can at least give you some usable results. A way to test if the scope is stiff enough is to collimate the scope pointing straight east, then leave the collimator in and slew so it's pointing straight west, if the laser is missaligned you found the reason for the flats not doing their job 100%

I would say if you want good images with a slow scope like that you need a mono camera to get the high SNR from luminance and preferably a CCD camera to get hardware binning for RGB. A OSC camera will be very noisy and in my opinion not worth the time and money spent on getting it up and running.

The lens isn't very sharp then, i have a ASI178MC with a Fujinon lens and it has much sharper stars

Focus seems pretty bad, maybe it would be easier to pick out the Ha if you get perfect focus?

In my opinion it's a pretty big engineering fail to make such a sturdy concrete pier and have long extensions of threaded rod, it can create unwanted vibrations when guiding and during windy conditions. The pier is nice thou and smart with the through pier cabling, also the "camouflage" is a good idea