Jp114

I saw this too, I was kicking myself for not grabbing a camera before it faded.

Thanks Stu, do you know whether it's possible to use Vixen's flatteners/reducers with a 2.5" Moonlite? They're a bit unusual (to me at least) because they're fitted inside the focuser shaft.

I've got an old Vixen ED114SS with the original rack and pinion focuser, and I'm hoping to make it easier to fine tune focus for astrophotography. I've seen that Vixen do an eye wateringly expensive dual speed upgrade kit (£169) but I've also seen a JMI Motofocus (£130) available. I've got an Atik AP setup and the weight of the filter wheel means that I've had to increase the focuser tension, so I'm wondering whether that will cause issues with the JMI? Also, does anyone know whether I can still manually focus using this? Their site mentions "electronic braking" for fine focussing, so I'm not sure whether that means I'd have to do all focusing using the Motofocus. As a side note, I bought a 2" Moonlite focuser (which is so nice) with the scope but it only had 1.5" travel and it was a pain to use with spacers. If I could afford to get one that better matches the scope, it would be decision made. Thanks, Jon

Hi, I'm based in Lydney, so it's good to see a couple of locals here. If you're on Facebook it's worth checking out the Forest of Dean Astronomy Group. If anyone knows of any decent locations away from the light pollution, I'd be really interested to hear about them. Thanks, Jon

I know my Vixen Skysensor 2000 (from the 1990's) has a feature that allows you to polar align without using Polaris. I've not used it, but I think that after alignment it'll slew so the alignment star is where would be if you were aligned, and you can adjust the mount to recentre it. I'm not sure whether any other controllers do anything similar though.

I'd agree with all that when you're talking about observing - but imaging is another story. When I've finally got the first clear night for weeks and spent ages setting up - something like hardware/software issues with guiding/acquisition has sent me to a very dark place in the past. When it works though, it suddenly seems worth the occasional anguish and financial cost.

If you can't collect the item, PayPal (not friends and family) is the only safe option. If it's a lot of money, I'd rather cover the fee myself for peace of mind. I was recently targeted by a scammer on SGL from a Wanted ad, I think it's my fault the classified ads are now hidden from newer users (including me)... The first contact was quite convincing, with pictures and detailed information but I had a couple of doubts and did a Google Reverse Image search. This revealed that he'd pulled the images and text from US based Astromart adverts, which meant he initially sounded like he knew what he was talking about. On ABAS I'm wondering whether the lunar eclipse question helps filter out the lazier scammers - I've never had a problem on there. Cheers, Jon

The first time I used DeepSkyStacker I opened my darks with my lights using "Open Picture Files", instead of looking at the line below, which is "Dark files" (Bias is two lines below). Needless to say, the image wasn't great... Is there a chance you've done the same? It might be worth trying it without Bias frames, just to see what happens. Regarding the darks, did you discard them because of their focal ratio (f/6.3 vs f/5.6)? If so, as long as the time and temperature match your light frames they'll be fine. Jon

I have to say, although a DSLR is a good choice, if you're planning to use a laptop (perhaps for autoguiding) I'd be inclined to pick up a dedicated camera if possible - there are bargains available on used cameras. I moved from a Canon 7D to a used Atik 314L+ and the difference is night and day. On the 7D, any stretching brought out loads of ugly green noise but the Atik 314L+ subs are really clean.

I can see the results of my guiding issues, hopefully now resolved... My sampling status is based on CCD Tools calculator. Apart from the guiding, the stars looked ok to me.

I recently tried using a Canon 70-200 f/4 at 200mm, with and Atik 314L+ (6.4 micron pixels), so I was severely over sampling. I think this was 7 x 300s through a Ha filter, I was planning to grab some Oiii but the clouds rolled in. I’m happy with it though.

I’m not too far from that area, I’d definitely appreciate a heads up on some decent dark sky locations.

I’m glad I stumbled on this post, I hadn’t even considered binning in PHD.

That would definitely point to CA being the culprit then.

This was the image that initially revealed the problem. The thing that prompted this question was when I was imaging M16 (using an inappropriate SCT focal reducer) the issue was worse but I couldn't see this at the time (I didn't have any stars bright enough to see decent diffraction spikes using the Bahtinov mask). Using my quite basic setup, I'd have to slew to a bright star, refocus and slew back to the target and manually recompose the shot. I haven't tried focussing OIII first yet. It's a full moon so my only recent chance to get out was just using Ha. Hopefully I'll get a clear night this week so I'll give it a try.

Thanks all for taking the time to answer. I don't think that temperature is the issue here, although it's definitely something I'll bear in mind in future. I've attached some subs (with crops) that were taken a few minutes apart. Obviously I'm only comparing the stars here and I'd expect the Ha stars to be a bit tighter. When I get an opportunity I'll grab an image through the each filter using a Bahtinov mask, that should hopefully show where things are falling over. Ha OIII Ha vs oiii Thanks, Jon

Thanks for the reply, motor focusing sounds interesting. I try to keep setup as simple and fast as possible but this could be a worthwhile step. I have to say, I've been drooling over a scope upgrade for a long time so I'd better make a decision there first.

Hi, I've been using a mono camera (Atik 314L+) over the Summer (weather permitting) and in my first attempts at LRGB I noticed that the blue channel was a bit soft. Since then I've been shooting in Hydrogen Alpha and Oxygen III (HOO). I've started by focussing on a bright star (using a bahtinov mask) through the Ha filter, grabbing the Ha data and switching to Oiii, but when I'm processing the Oiii images they're definitely slightly out of focus. Before I tried narrowband, I suspected that the blue filter might not be parfocal, but now I'm thinking that the scope might have a significant amount of chromatic aberration. The Ha and Oiii filters are next to each other in the filter wheel so I don't think something's out of line there. Sometimes I can refocus the Oiii without moving off the target but mostly I can't see stars bright enough to check the diffraction spikes. I would do some testing (now I've got an idea what to look for) but Clear Outside is just showing clouds for the foreseeable future... I'm using an Orion ED80 and all of the filters are all Astronomik, so they should be parfocal. Is it normal for channels to be that far out? I'm wondering whether it might be time to get a higher end refractor... Thanks, Jon

I’ve never seen The Dumbell looking like this, it has to be worthy of APOD.

I've been on the lookout for an Atik 314L+ and I've been offered one at a good price but I've been thrown a curveball. I've also been offered an Atik 450M, which is a bit more but still a good price. Thanks to both sellers, if they're reading this. My scopes are Orion ED80 (used most often) and Meade LX90 8" (used @f/6.3 when imaging). The Astronomy Tools CCD Suitability Calculator puts the 314L+ (6.45µm pixels) as slightly under sampled on the ED80 but right on target on the LX90 (both binned 1x1). The 450M (3.45µm pixels) places the ED80 right on target and on the LX90, with 2x2 binning, that's also in the right place. According to the maths the 450M would be most appropriate but I'm wondering about the loss in sensitivity with much smaller pixels (although binning can address that). Also, I can't really find much online about this camera and that particular sensor doesn't seem to be used in other CCD cameras, so it's a bit of a mystery. The Atik 314L+ has loads of great images attributed to it and also can double up as a guide camera if/when I upgrade. It's worth mentioning that both sensors are 2/3" format. I'm really struggling to choose. Does anyone have experience with both of these cameras? Thanks, Jon

Good work. Is the camera modified?

I’ve also recently got my Mintron (the 1/3” version) and an ancient laptop going, mainly for auto guiding at the moment. I used to image with it using: https://www.coaa.co.uk/astrovideo.htm I hope this helps. Jon