JSeaman

In case anyone else has to do this, my solution was this:

Pixinsight
    Debayer to RGGB as a batch
    Batch format conversion to TIFF 16 bit

Photoshop
    Added and action for hue adjust and close

    Batch automation with supressed colour profile warnings to all TIFFS

PIPP

    Join mode to create an AVI
    Input Options -> Colour Debayer -> Debayer monochrome frames (untick Debayer raw image files)

I'm just having my first play using a ZWO 224MC as an all sky camera. I have it working nicely with 8 second frames but I'm getting a green cast when I use PIPP to generate an AVI. This is due to the RGGB bayer matrix but I'm wondering what approaches people take, do you pre-process the FITS or post-process the video or something else?

Thanks

James

Correct on both counts. Two batteries in series for double the voltage makes the winch operate much quicker. I use one of the 12V cells for the relays (Which are less tolerant of 24V but often work OK)

The cheapo winches are a bit slow and very noisy, if you want to operate in the middle of the night then you could upgrade but if it can wait until daytime this works well

Yep I run it at 24V with no problems but you can do this with most winches

 It's really easy even if you're a novice, just grab some 1mm steel and hacksaw/bend to your heart's content.. You could probably do it out of wood/cardboard etc. in a pinch. Just expoxy it to the main drum of the winch and wrap your rope in opposite directions

Hi Steve, just buy any normal winch and then make a divider on it. 

Some pics of what I did ...

Bought a winch

Took the barrel out and drilled a second hole

Made a divider (cut a circle with a slit, bent it open then put it on the barrel and bent it back, was going to weld it but it was a good fit

Wound one rope one way and a second in the opposite direction then you have push and pull!

No, the coma corrector is only in the loop because I'm trying to minimise what I disturb to switch between my 1600 and the 224, I was hoping it wouldn't interfere and it doesn't seem to. The weird shapes are probably due to poor seeing and not much data. I was only pulling in a bout 2 FPS but I've fettled with the USB settings and dropped to 8 bit and it's now showing 20fps so I'll try again when it's clear

It has been a couple of years since I have even tried planetary but for £165 I couldn't resist a 224MC. This was my first go with my 12" Newtonian with a Coma Corrector and 2xBarlow all in the chain and it worked OK. I need to get plate solving working with this set up next but I'm happy to have taken a picture at least. This is the best 40% (I started at 5%) of a 3 minute SER video of 0.02 second exposures

09.tif

Yes the winch is push/pull, simply put a separator on the spool and wind one side in the opposite direction. This unspools one side while spooling the other to open and then reverse winch direction to close

I went for U section steel and nylon casters (~£70), works well. 

To automate it, I went for a winch (£60) and a few pulleys and some wire rope (~£25 for a large kit). I have the option of either a manual opening or Arduino to trigger the relays, it works something like this :

To open, I flick my rotary switch and press the button to start. To close it, I do the opposite.

Alternatively, driving the relay via a FET off an Arduino will do the same thing

Ha, what a feature - well found and congrats, fingers crossed it's plain sailing from her on out

Hey no problem, we've all been there. The night you accept you're going to spend the whole time solving the problem it tends to go away Just be methodical and you'll figure it

No sorry 450mm guide scope and PHD2 not a StarAdventurer

Good luck tonight, hopefully you can narrow things down further. The guide assistant is definitely a great place to start and will tell you what it finds, just ping up a screenshot

I think the 20 minute drift will be interesting too

You'd have to have some pretty sever imperfections. Try slewing the mount a long way on highest speed and see whether it is smooth

I'd definitely be inclined to do the guide assistant, it can reveal a multitude of issues

Pulse size change might make it react to the point it can catch it but there's an underlying issue to find

Yes, 8000 is quite big but fair enough

Cool, so if it's well balanced you will be able to nudge it around in RA and DEC and it will stay put - worth checking you can do that in a few places. Even the weight of cables can make a difference but the issue you have feels like something larger!

Yes your focal length will be a factor but I was at <1" with 450mm 

So does the motor start driving the scope when it runs away?

I'd definitely be inclined to give it 20 minutes running by itself and see what happens. You can potentially do that when it's cloudy too as long as you can measure the movement somehow

The star loss looks like a symptom, the mount moves so the star goes but the RA runaway happens first and the SNR of the star is good right up until then

Have you run the guide assistant? Did you increase the pulse size?

I can see massive spikes which the mount is recovering from then it fails at the end:

Have you checked your balance in the orientation the scope is on this target? With clutches off does it stay in position?

Guiding of +/- 5 arc seconds I wouldn't be able to image at all, that gives blobby stars for sure

If you sit next to the mount when it goes wrong can you hear the motor driving?

Have you tried leaving it without PHD to see if you get runaway?

A corrupt SD card won't do you any favours

It sounds like you should run the guide assistant in PHD and report back, it should give a good indication of what your issue is

Do you see these:

Do you have a log file?

Still drifting a lot in Dec?

Did you increase the pulse size?

Although you don't need ASCOM for the mount you still need a driver for the camera (ASCOM or otherwise)

Thanks, this is what I tried to show in the picture with the calipers above, 55mm to sensor

Thanks that's interesting, I have just spaced mine out a little further and will check that. From the first picture to the second was night and day so I'm assuming I have the lens correct now and, as you say, the other one doesn't matter. I'll try this tonight and see what happens!

Collimation looks very good, I did a tiny tweak on the primary but almost nothing

I've added about 0.5mm into the chain and will re-test that later but it's not a very scientific approach!

I got myself into a pickle last night! 

The night before last I tried my new coma corrector (Baader 2" MPCC Mark III) and found I had lots of dust and marks in my image. I popped it apart, cleaned out all the dust and tested it last night. The first image I got was terrible:

After a lot of back and forth I ended up inverting the second element of the coma corrector and that seemed to improve things:

All four corners have the same issue though, coma with the tail pointing towards the centre of the image (this is the bottom left)

I double checked my spacing this morning and think I have a correct 55mm: 

So this morning I downloaded CCDInspector, a tool I don't fully understand, and produced this graph which may or may not be ok?!

I found the following image which shows what the FOV is like when the coma corrector is too close:

So I'm looking for a little guidance, should I just start increasing the spacing and trying my luck? I will check collimation again in a mo but I think that's OK. The focuser (stock 300PDS) doesn't appear to be sagging so I'm not entirely sure where to go next, thoughts welcomed!

James

OK well just shout up if you want a hand, this is something I do fairly often with little trouble in PS

Ah right, the file was created but was empty. It had worked all previous sessions and no permissions changed so just a glitch I guess

Sorry not sure what you mean by w on?