Starflyer

Can I ask why you moved the spider to a 90° orientation from 45°? It's probably a personal preference thing, but I much prefer X shaped diffraction spikes to horizontal / vertical spikes.

Cracking camera in its day, take a look at the planetary images people were taking with it.

Hi Brendan, That bit is a quote from @Avocette post further up. I haven't tried this yet, I need to get the hardware together and then I'll probably try it with Mire de Collimation, I don't have much experience with SharpCap. Cheers, Ian

Thank you so much Ed, I had no idea that flange was 2" fit, great stuff. Cheers, Ian

I use an OAG with both my scopes, a 1200mm fl newt and a frac at 332mm fl, it just works and I don't need to worry about differential flex. I have a pier but have to set up the scope and camera each night I image. Using an OAG means that the camera, with the change of one adapter, is ready to attach to either scope, no moving a separate guidescope from scope to scope. The main reason for me moving to an OAG was that I was plagued with differential flex, I tried for a couple of years to get rid of it but gave up in the end. I'm so glad I did, I know people image very successfully with separate guide scopes, I couldn't make it work and a couple of years of throwing valuable subs away was enough for me. I have mine set up as; coma corrector or reducer / OAG / filter wheel / camera, that way I get nice round stars in the OAG to guide on. I guide with a Lodestar and always have at least a few stars to guide on, often many more.

@Avocette I know this is an old post but I'm interested in trying your method with an ASI120 MC-S. I'd have to buy the camera and the CS mount lens, can you show me how it fits together with a 2" nosepiece please, and is the 2" nosepiece supplied with this camera, from FLO's page I can't see that it is? Pictures would be great if you can, your description is good but I can't get my head around how I can have a CS lens and a 2" nosepiece attached at the same time. Cheers, Ian

Watch that doesn't mark your scope. Rubbery / plasticy things tend to leach pigment over time and may stain your lovely white tube. I know this from experience when I made some rings to stop a newt sliding downwards when rotated, the marks didn't polish out either.

I don't see halos, they're more like concentric rings to me. The bottom right star looks smeared by sensor tilt or spacing with some hint of triangular stars in that part of the image in general.

I always struggled with getting the secondary exactly centred and appearing as a perfect circle, that's why I bought the concentre device Craig. I always struggled with a Cheshire on the secondary, and found a laser to be worse than useless. Treat yourself to a concentre for xmas 😃 Concentre for the secondary, decent cheshire for the primary and then star test.

If you replace the stock focuser you should definitely check it's square to the tube before collimating. This means removing the secondary and taking measurements to enable you to make a mark on the tube exactly opposite the centre of the focuser opening. I can't find the procedure now, but it's documented somewhere on SGL. Once you've marked your tube (Tipex is good for this), use your Cheshire in your focuser, still with the secondary removed. The crosshairs should exactly point at the mark you made on the tube opposite the focuser, if it doesn't then your focuser isn't square to the tube. I have a feeling that this is your problem. If your secondary mount is central to the tube and your secondary presents as a circle, but your secondary is not centred when viewed through your colli cap / Cheshire then it's a tilted focuser.

And the fact that they add nothing to security. Burglars love to be able to see where they're going, makes their lives much easier than either carrying a torch around or falling over stuff.

A dew shield made from a rolled up camping mat, closed with duct tape, will really help reduce stray light. Make it so around eight inches sticks out from the end of the scope, and tight enough so it doesn't slip off under its own weight.

My 460EX will be up for sale in January 😉 I'm not expecting more than 50% of the new price for it even though it's pristine.

I'm a die hard CCD user, even twelve months ago I was wondering what all the interest in CMOS was and truly believed it was all marketing generated hype. CMOS = DSLR type sensors right? This is absolutely not the case any more. After doing a lot of reading and research I believe that CMOS is now, not the future, the technology has matured to the point where it makes no sense to buy a new CCD camera. I'm waiting for the ASI2600mm to be launched and then I'll be moving to CMOS. Sure, everyone has the right to their own opinion and to buy what they want to. If I was the OP I'd welcome advice like this, I know it's not what they asked but the advice is sound and the latest CMOS cameras have huge benefits over CCD. That said there will be more and more CCDs coming onto the second hand market, grab yourself a secondhand bargain if CCD is what you want.

Thanks Julian, I should have mentioned that it's for my 10" newt, it'll be mounted on my obsy wall. Looking at the price of Electroluminescent panels at that size I may try a tracing pad first. I'm also wondering how big the panel will need to be to give even illumination from around two feet away.

I came across this project and wondered if anyone here had built one. https://www.blackwaterskies.co.uk/2020/03/cheap-diy-remote-controlled-flat-panel/ I see loads of A3 led tracing pads on Amazon but have no idea from the listings how they're illuminated. I was hoping someone could point me in the direction of a good 'un. Cheers Ian

I really need to try it under the stars, I've had it set up and looked around a few times. I currently use SGP but won't be upgrading to their subscription model. Everything works, albeit with the odd SGP connection problem at start up that I've grown to expect. Next year should be obsy build year for me and I'd like to get automation set up for the roof from the off. How are NINA's observatory automation controls, can you use rain / cloud sensors to flag unsafe conditions and park the scope / close the roof? Cheers Ian

There is a way to get an accurate home position with EQMOD in daylight, using a spirit level. It's been a while since I did it, but it goes something like this. Click once on the little button beneath the ASCOM logo (it has a window and a plus-sign). The display changes to the two rings Unpark, rotate RA so it shows 12:00:00 or 00:00:00, choose whichever gives you a flat surface on your mount casing. Place your spirit level on your now (almost) horizontal mount, unlock the clutch, set it level and lock the clutch again. Park, unpark and then slew DEC to 180:00:00 or 270:00:00, choose whichever gives you a flat surface on your scope. Place your spirit level on your now (almost) horizontal scope, unlock the clutch, set it level and lock the clutch again. Park, clear any alignment data and you're good to go. I used this for years before changing to a mount where I can't use EQMOD any longer. If your PA is good, your location and time is correct and you set an accurate home position your life will be much easier, well your alignment anyway 😃

SGP is paid for, I've used it for a few years now, it can be temperamental at times. I tried NINA recently, it's open source, so free unless you want to donate, and is every bit as capable as SGP. I'd say try NINA first.

I'm not sure how autofocusing works in APT. SGP, NINA etc generate a focus curve Like this, the shape of the curve can help diagnose what isn't working properly.

Back to the original question, I've imaged successfully in a near gale with an 80 frac and an EQ6 Pro. With my 10" newt I lose frames in anything above a slight breeze.

Best to try and fix it in the longterm, autofocus isn't just about getting you best focus at the start of a session, it's about keeping you in focus as the temperature drops. With my frac I need to refocus every 1.5°C temp drop or the focus shifts noticeably. Even at this time of year it can drop a good few degrees in the first couple of hours. What software are you using, maybe you can post up pics of a V curve or two?

You need premium support to get any answer now 🤣 I feel Main Sequence Software will be no more within a year or two.

Great thread Craig, you'll be able to help me out when I build my obsy next year.

I've been hanging onto CCD for years now, the 2600MM will be my next camera though.