david_taurus83

Well folks, I've had a play this evening. I've removed the Hotech and put the Flat6 reducer back in. Configuration now is 2" nosepiece, tilt adapter, reducer, spacers, fw and camera. This enables me to dial in correct spacing without messing it up with an adjustment to the tilt adapter. I think I've got spacing correct. I started off by pointing at the zenith and then looking east and then west. The star elongation was pretty much the same each time so this ruled out flexure or sag in the focuser. I also tightened up a few brass screws in the drawtube before starting. It took about 4 trips out to the scope to tackle the tilt adapter with the allen keys but I think it's a huge improvement. Not perfect in the corners or edges, particularly the right hand corners but the edges get cropped out anyway after stacking. Across the middle looks loads better to my eyes. I will get things marked up tomorrow and measure the tilt adapter with some calipers and make notes! I'm going to get one of those TS t2 5.5mm camera rotators so the assembly can stay in the same position and I can frame the camera independently. The previous stack and a single sub from this evening below.

Yes, when I rotated the camera the elongated stars went from the side to the top.

When I started the other night with the reducer it wasnt this bad. I switched to the Hotech to see if it was any better but it looks worse. I'm thinking the SCA section isn't compatible with my scopes. They both have 2.5 inch drawtube but the 2" adapter isn't very deep. I had to arrange the rubber bands on the SCA to the centre, ie 3 together just so they seat within the adapter. I'm thinking this could be a reason. The focuser cant be this much out. More testing tonight I think.

Yes, pretty much!

Don't think I can carry on with this. Going to have to take apart and try and sort it.😓

Thanks for this tip Olly. I've always just tried to align them as central as possible as the foot of each channel is rarely the same width in my images. I will have a go with this next time round.

Have you calibrated/centred the polarscope? When I got mine the reticle was loose! I've never actually used it... With a very good polar align (digital aid via Polemaster or Sharpcap) you should easily get 2/3 minutes unguided as that focal length is forgiving. It's a good mount but still considered "budget". Have you considered guiding? I can easily get 15 minute subs out of my AZEQ6 which is essentially the same internals are the EQ6-R.

Altair version is a bit cheaper. https://www.altairastro.com/Starwave-102ED-FPL53-Refractor.html I have this scope and I'm very happy with it for observing. Jon @parallaxerr also has one and he is a more experienced observer than me so be interesting to find out how he finds it?

The stock R&P focuser on each scope. They're pretty good to be fair. Both the same so I can just swap my autofocuser between them. It's got to be a slight misalignment between focuser and lens cell, and then another slight shift in tolerance between flattener, spacers, filterwheel, camera and also the amount of glass photons have to pass through to converge at a single point on the sensor! No wonder Taks are so expensive! As much as I hate to say it lads, I'm glad I'm not the only one!

The only thing I can think of is to put a tilt adapter onto a nosepiece and leave in the focuser. Flattener, spacers and camera threaded to flattener. Dial out tilt. Leave nosepiece untouched from that point on. Framing of an image? TS 5.5mm camera rotator to rotate camera only?

As titled, how common is this problem? I tried the 102ED-R out for the first time last night and my old buddy, tilt, came along for the ride. That's 3 different scopes I've had now that have some sort of distorted stars at the edges. So trying to dial in the correct flattener spacing is difficult as you end up chasing your tail. Stars ok one side, coma on the opposite. I have a tilt adapter which fits in between flattener and camera somewhere but the problem with that is if it's in the focuser, as soon as you change orientation to frame an image any adjustments made go out the window. Example of last night, I started off with a 0.8 reducer, everything threaded connection. No good. So then I switched to the Hotech SCA and worked at F7. Still the same. Tilt on one side. I rotate the camera and flattener 90° in the drawtube, tilt moves from left side of image to top. So its definitely not the camera. Surely I'm not the only one to wrestle with this? Anyone got any tips or ideas?

None of those links show the mini ball head? Is that a separate purchase?

It don't need adjusting like a RDF?

How do you adjust it?

Not really a shot in action but it spends more time in this position than anything else! Changing things up from this: Some difference! To this! 102 EDR is ready! Chance of less clouds later. Hopefully get to do some testing. What's the chances of the flattener working straight off the bat?🤔

I use a WO GT71 420mm F5.9 triplet. I think the Hotech spacing is dependant on focal length more so than focal ratio. Alan's works at the quoted 55mm. Explore Scientific do a flattener for your scope. Have you considered that?

I have one of those. Yes, you can thread 2" filters into the nosepiece. Spacers, you'll have to experiment. Start at 55mm and see how you get on. It's not enough for my current setup. Its somewhere between 70/80mm for me. Still working on it!

Astro darkness ends soon for a few months and the bright evenings means you'll be limited to just a few hours from 11/midnight onwards. Also, going unguided means you'll be limited to shorter exposures, uncooled camera will be susceptible to noise especially with warmer weather. Is the 450 modded? If so you could try something nebulous like NGC7000 but youd need lots of short exposures. M13 might be a good target to try first. A good polar align and plenty of 60s exposures at ISO800 should work. Practice your polar aligning and see how long you can expose for without star trails.

How much input is needed to setup the SM? Is it easy to use? This is coming from someone who's only ever used Windows. Do you need Linux to run it? I have a laptop here that's in the drawer unused...

The ASIAir supports DSLR now and works off a tablet or mobile phone. No PC or laptop needed whatsoever. It has internal guiding and platesolving. Basically plug and play. But definitely tailored more to ZWO products. If it would support my autofocuser (DeepSkyDad) and offered more control over guiding and dithering I would be all over it. Don't think I can give up the functionality of APT for it just yet. The Stellarmate is probably much more functional with wider support options but it needs a bit more user input to setup, (from what I gather as I've never tried it) and I'm not sure whether you still need a PC to control from your 'warm room' side of things! So if you want a fully mobile setup and you have ASI or a DSLR cameras, I would say the Air is the way to go. FYI theres a very good group on FB for the ZWO ASIAir with plenty of support. I've joined it to keep tabs on development. The Air is not without its bugs and niggles but ZWO themselves are active in the group and do take stuff onboard. That said, even with a laptop the hobby isn't without its bugs and niggles...

Yes definitely a USB traffic issue. For ages I thought the issues with my 1600MM were because I use a Startech USB2 to CAT5 extender. It had a quirk where the 1600 wouldn't download images unless the 120 was looping frames in PHD!!! Every now and again it would also just give the dreaded BUSY message in APT and could stay that way for hours until I stopped the image plan and restarted it. Very infuriating as I couldn't take my eyes off it while imaging. Well, since moving to a modern laptop it works brilliantly. Downloads quicker and hasn't skipped a single frame. But then the 120 wouldn't work properly. It gives a split frame effect in both PHD and Sharpcap. Googling brings up results from CO and ZWO forums where it's a known issue for some. ZWO say they didn't anticipate such issues with USB3. As you have said though, the USB3 versions of the 120 and the new Minis have addressed the issue. I could have just swapped for one of those but it's nearly my birthday 😁

My 120MM works great in my old Win 7 USB2 laptop but I had trouble with the 1600MM. That's fixed now with the new laptop but the 120 wouldn't work!

New guide camera. The ASI120 is incompatible with my new USB3 laptop 🤷‍♂️

Yep. My routine is: Setup in home position Polar align in Sharpcap Take first image in home position Platesolve and sync Use the drift align tool in PHD to slew to meridian and celestial equator Calibrate Slew to target, platesolve, sync and repeat until on target. Run autofocuser Run image plan. Watch clouds roll in.

Thanks! I already pay for it! The reason for the demo version in the screenshots is because I wanted to do a fresh install of everything from scratch!?