tooth_dr

I agree that Venus shot is phenomenal. If that was in a text book and labelled as taken by a satellite i wouldn’t have batted an eyelid.

Thanks for this info guys. If I can indeed check for camera tilt this would be fantastic and eliminate/correct that aspect. I wont be getting time for a couple of weeks to do this but will update once I get a look at it.

I don’t think you’ll have trouble finding stars, you just won’t have as many with the 120MM. From personal experience with my current setup, the 120 wasn’t quite adequate for OAG, but the 290 gives completely hassle-free OAG guiding. I’m using it with a 1200mm F4.7 Newtonian. I just wanted to share actual practical experience rather than theorem.

I'll check my packaging later on if it's on it. What do difference do you think that might make?

I'm not sure, sorry! What OAG are you using, I've seen 10mm but not 12.5mm prisms.

Thank you! QHY268M for lum and NB, and a ZWO2600MC for colour. I also just purchased a labelling machine, so you can see that practically everything got labelled 😂

There is so little difference I dont think it really makes much difference between these two, but if you go larger eg 174, then you will get vignetting from the small OAG prism (typically 8mm x 8mm). I have no personal experience, and have found the 290MM works great. Incidentally I still use the 120MM with a guidescope and it works perfectly as the demands are much lowers in terms of sensitivity.

Yeah same part of the sky, I think it was M51, which is notoriously bad for guidestars. I've been doing imaging long enough to compare apples with apples 😉

Hi Vlaiv No theoretical analysis on my part - I found 1-2 stars with the 120MM with gain at 100%, switched to a 290MM getting 20+ stars to choose from, even with gain turned down, at times to 50-75%. Both work fine as a guidecam with a short focal length guidescope, but as an OAG, the 290MM is just better as it works.

It’s the sensitivity not the size of the sensor. The 290MM is just better despite having smaller pixels.

I switched from a 120MM to a 290MM due to lack of stars in OAG. I would disagree with vlaiv. I found the 290MM to be 10x (or more) better compared to the 120MM. I also think the 120MM is flaky in terms of usb connectivity.

Cheers. No it’s not new, I bought it used a couple of months ago. It’s a 2015 scope. I hadn’t heard about the new delays. Flip that is 18 months

@LeftyAstro wow now that’s a halo

Here mine 😜 APM LZOS 105/650 with 0.75x RR reducer, 3.5” FT focuser with motor.

Sorry to hear this, must be extremely frustrating and disappointing that you havent had your mount for several months and are out of pocket.

Very high quality work Alan, definitely click and zoom in to get most out of the superb images

I agree that the 3.5nm Ha is the one to go for, as you can image around the moon more, well worth the extra £ given that most nights that are clear seem to have the moon around. Actually when the moon isnt around and it is clear, I tend to gather broadband data (and occasionally Oiii data) anyway and not NB in general! I live in a decent/low Bortle 4 location too.

Thanks again Alan. Going to take time to read this properly later. The Tak doesn’t have a built-in internal flattener, it’s screwed into the focus tube but is removed for collimation. It’s spacing is in fact is very critical, with a quoted spacing of 55.2mm required!

Is it possible to adjust the front plate of the QHY268M, I thought it was but cant seem to find any info.

Hi Alan Thanks for doing this. I've no idea exactly what the figures mean, but it looks pretty bad! I had a very short imaging session last night, and spent some more time tweaking the autofocus routine - I added more points and this seems to have helped. I dont want to upload any more images as I dont want to take up any more of your time, but the tilting looked less obvious (but still there). I'll look into getting a trial version of CCDI, as it seems quite costly 😫 The camera is screwed onto the flattener, which in turn is screwed into the focuser tube. Is it possible the camera chip could be tilted?

There are a few members following this thread, you might get into/images in there or a better response?

Nightmare. It may or may not be relevant but I’ve found it impossible to use my 120MM mini and 2600MC in APT together. Lot of weird stuff happens - random disconnects and recently I connect to the 2600 and take an image with it, but the image size is that of the 120! I’ve always had trouble with ZWO stuff and still of the opinion it is a bit flaky when you connect >1 camera. I own several ZWO cameras - 120MM, 120MM-mini, 290MM, 178MM and a 2600MC, they are good cameras but software/driver-wise I'm on the fence in terms of compatibility.

I can see what you mean now, maybe a processing anomaly

It is an oblate spheroid because it spins so fast, it looks flattened out.

100% agree Stu. I think I just found the comment a little inflammatory, and assumed moderators werent supposed to take sides