ATIK Conversion

[StevieO]

Pinch me, guys, my new ATIK 383L+, filter wheel and filters  have arrived and today is the day I convert from unmodded DSLR to NB. I confidently expect the learning curve to be vertical. Miraculously, the forecast around here (Somerset) is clear tonight, so I'm in a race against time to install software and read documentation before getting out to my dark site. I don't expect much in the way of results to start off with, but will post some first lights if they're any good.

Cheers

StevieO

[belfieldi]

Good luck with the new toys!!

[JamesF]

It's a brave man who believes the weather forecast for this end of Somerset, at least.

At 9am today the forecast was for clear sky all day.  By 11am we had 100% cloud cover

James

[ChrisLX200]

Once you get it focused it's all plain sailing :-)   Processing the data on the other hand....

[only joking, it's easier than OSC data from a DSLR that's for sure]

ChrisH

[Stratis]

Good luck mate!

Recent convert myself from 6D DSLR to QSI 583, with the same sensor as yours. 

My early advice is take many darks at many exposures and temperatures. Do this on cloudy nights. I'm building a library of darks at -10C, -20C and -25C and 3, 5 and 10 minute exposure.... that seems to cover the most bases. Now if only I can figure out how to eliminate hot pixels....

[StevieO]

Good luck mate!

Recent convert myself from 6D DSLR to QSI 583, with the same sensor as yours. 

My early advice is take many darks at many exposures and temperatures. Do this on cloudy nights. I'm building a library of darks at -10C, -20C and -25C and 3, 5 and 10 minute exposure.... that seems to cover the most bases. Now if only I can figure out how to eliminate hot pixels....

Thanks, in the end there was too much setting up and reading of manuals to do to go out last night, so the Atik spent the night in the fridge gathering darks and will probably be there at least for the rest of today and for several days when I'm not out imaging.

StevieO

[carastro]

Why did you need to put the Atik in the fridge, it's a cooled camera with set point cooling?  

Unless you have the central heating on and want to set it to a ridiculously low temperature.

Carole 

[StevieO]

Why did you need to put the Atik in the fridge, it's a cooled camera with set point cooling?  

Unless you have the central heating on and want to set it to a ridiculously low temperature.

Carole 

True, but it's also dark in there with the door shut, and Atik recommend a dark environment to prevent light leaking in through the mechanical shutter. It's also where I used to put my Canon when I was collecting its darks and the habit stuck - there's a handy shelf for my laptop next to it.

[swag72]

I have found that it's much easier to have just one working temperature - I use -15 degrees as mine. I can achieve that temperature all year round summer and winter, day and night. That way, I only have to take darks at one temperature and so I only have to bother about exposure length. Even then, I generally use 30 minutes subs and so just need a 3 sets of darks in total - 1800s for narrowband, luminance (probably 600s) and then a set for RGB (300s) ....... job done!

[beamer3.6m]

True, but it's also dark in there with the door shut, and Atik recommend a dark environment to prevent light leaking in through the mechanical shutter. It's also where I used to put my Canon when I was collecting its darks and the habit stuck - there's a handy shelf for my laptop next to it.

 Your assuming the light goes off when you shut the door - The age ol'question. 

[StevieO]

 Your assuming the light goes off when you shut the door - The age ol'question. 

It does, I've checked by taking an exposure inside!

Here's a question: My setup shown in the photo, is quite rearwards heavy, though it's as far forward as I can get it without fouling the focuser on the dovetail.

Would the tracking performance of the mount suffer, even though the setup is much lighter than the 18kg imaging limit of the NEQ6?

Regards

StevieO

[StevieO]

I have found that it's much easier to have just one working temperature - I use -15 degrees as mine. I can achieve that temperature all year round summer and winter, day and night. That way, I only have to take darks at one temperature and so I only have to bother about exposure length. Even then, I generally use 30 minutes subs and so just need a 3 sets of darks in total - 1800s for narrowband, luminance (probably 600s) and then a set for RGB (300s) ....... job done!

That's occurred to me too, Sara, I'm doing all my darks at -20 degrees and will see how it goes. This being the UK I'm assuming it'll be colder here than in Spain! 

Regards

StevieO

[swag72]

In my experience, decent balance makes a real difference. I have a scope that is probably 75% less in weight than the load capacity stated. I was surprised to see what a difference in guiding accuracy decent balance had even at this margin.

[StevieO]

In my experience, decent balance makes a real difference. I have a scope that is probably 75% less in weight than the load capacity stated. I was surprised to see what a difference in guiding accuracy decent balance had even at this margin.

I thought as much. I'll try rotating the scope by 180  to clear the focuser and move it forwards more. It'll look all wrong, but what the hell?

StevieO

[Uranium235]

I have found that it's much easier to have just one working temperature - I use -15 degrees as mine. I can achieve that temperature all year round summer and winter, day and night. That way, I only have to take darks at one temperature and so I only have to bother about exposure length. Even then, I generally use 30 minutes subs and so just need a 3 sets of darks in total - 1800s for narrowband, luminance (probably 600s) and then a set for RGB (300s) ....... job done!

I can second that, I do -15 in the summer and -20 during winter months. Having said that, I dont use darks (I sigma clip or use kernel filters) - but temperature also has an effect on the flats with the 383 (higher temps give a false ADU reading when taking flats).

Also, when focusing - remember to use the subframe tool in artemis to draw a box around your star of choice, select "pre". Then hit loop (1-2 sec should be enough) and only the selection you have made will be downloaded, it makes for pretty quick focusing feedback (though not as fast as a shutterless camera).

[Stratis]

I have one word of caution about putting things in the fridge: the fridge can be an extremely moist environment and that can be *very bad* for your electronics if it has a really cold CCD in it somewhere.

Make sure your fridge is well-sealed and you haven't just put a load of veggies in it!

[StevieO]

Also, when focusing - remember to use the subframe tool in artemis to draw a box around your star of choice, select "pre". Then hit loop (1-2 sec should be enough) and only the selection you have made will be downloaded, it makes for pretty quick focusing feedback (though not as fast as a shutterless camera).

Thanks for the tip, I'm expecting to miss the Live View facility of BYEOS and Canon Utilities, but that sounds almost as good. Presumably with a reticle in place the same 1-2 second looping technique can be used for star aligning.

StevieO

[Uranium235]

No prob

Another neat feature of Atremis is the marker function. Use that to mark the bigger stars in you images and that will allow you to reframe on the same spot over multiple sessions.

[beamer3.6m]

It does, I've checked by taking an exposure inside!

It was a joke (based on an old fashion sketch I think). I realise the light goes off in a fridge.

[JamesF]

It was a joke (based on an old fashion sketch I think). I realise the light goes off in a fridge.

Unless the fridge belongs to a certain Mr Schroedinger.  Then you can never be sure...

James

[ChrisLX200]

Unless the fridge belongs to a certain Mr Schroedinger.  Then you can never be sure...

James

Nope, you can only be sure if you actually look to see whether it's on or off... :-)

ChrisH

[Stratis]

One quick focusing tip if you're using an OAG is to pick one filter (I use green from an LRGB set) and achieve perfect focus, then lock your OAG to be precisely parfocal with it. 

Now you don't need to use your large CCD for focusing and mess about with ROI, you can just focus with the guide camera.

If you want to be truly pro, mark off all your other filters as dispersion from that central point; neglecting temperature variation for a moment you should be able to get close-to perfect focus with a single focusing pass and some careful knob-twiddling (if you know what I mean)

EDIT, and if you want to plunge utterly off the deep end, you can start comparing the dispersion curve from an RGB filter set for each of your scopes, and actually be able to define the difference between 'Apo' and 'Semi Apo' etc....

[ChrisLX200]

One quick focusing tip if you're using an OAG is to pick one filter (I use green from an LRGB set) and achieve perfect focus, then lock your OAG to be precisely parfocal with it. 

Now you don't need to use your large CCD for focusing and mess about with ROI, you can just focus with the guide camera.

If you want to be truly pro, mark off all your other filters as dispersion from that central point; neglecting temperature variation for a moment you should be able to get close-to perfect focus with a single focusing pass and some careful knob-twiddling (if you know what I mean)

EDIT, and if you want to plunge utterly off the deep end, you can start comparing the dispersion curve from an RGB filter set for each of your scopes, and actually be able to define the difference between 'Apo' and 'Semi Apo' etc....

One slight problem with that - the OAG needs to sit in front of the filters otherwise you're having to guide _through_ the filters (try that with an Ha filter...). However, if your OAG is in front of the filters and focus is being necessarily adjusted for the main camera, you'll find each filter needs different focus offsets unless all are exactly parfocal with each other (and they won't be - mine certainly are not anyway), so the OAG cannot be in focus for all the filters at the same time. You may be able to get away with using an OAG that is not in good focus, or you may not. They can be frustrating things to use.

ChrisH

[StevieO]

Well, I got my first light, choosing the Crescent Nebula for the honour. I did an hour each of Ha, OIII and SII, in 10 min subs unbinned. I was going to get another hour of Ha but the nebula was directly overhead and the mount started to foul the camera and I lost tracking.

I stacked in DSS and combined into an RGB image in PS using Anna Morris' excellent video  as my guide. It's very rough and ready, and I'll do a better job of it when I have more time, but, for what it's worth, here it is, my first NB effort. Any comments about how to stretch it better will be welcome. I'm amazed at how much colour has come out, although I may have been a bit heavy handed in the processing.

Cheers

StevieO