I am already thinking of one for the little ED72 as well as my Celestron one for my SCT. The ED72 does not seem to change focus much with temperature but for imaging, the fewer times you touch the scope the better, IMO. Hopefully something pops up in a reasonable price range.
I suppose with the rise in affordable cameras there's a growing interest in astrophotography. For this, motorising your focuser makes sense. With automated software like SGPro I can just let my scope run all night gathering a few targets and keeping focus throughout.
Guess I am a Luddite, as I am against them. I went through a phase of putting a motor on my TS APO, and letting SGP do the work but I was unhappy with both the outcome and the cost. I am trying to simplify my setup not make it more complicated. I found that often the SGP focus was not that sharp, and that my Batinhov mask gave much sharper results. Motorised focusers also waste a fair amount of imaging time and are another thing that requires power, cable management, etc.
For my setup, where I have matched filters, which are parfocal, switching them on the wheel does not alter focus in the image file. I can start a run and come back a couple of hours later and the focus is still perfect. I rarely bother checking anymore.
But hey, give it a go, if you don't mind the hassle.
Two caveats to note: you must have an excellent imaging capable focuser on your scope, which will not slip, twist, etc; and your equipment must be at equilibrium (adequately temperature adjusted). Scopes with poor focusers would obviously benefit from SGP focus checking.
If I can get auto focus to work reliably and repeatably on my SCT I am keen for that as it does change focus significantly with temperature changes. Even just having it make automated changes between subs based on a measured temp coefficient will get me better data.
I have used the focus motor for one night on the SCT and even for manually focusing I am sold on it. I am pretty firm on the idea that the less you physically touch the rig in operation the better.
I am already thinking of one for the little ED72 as well as my Celestron one for my SCT. The ED72 does not seem to change focus much with temperature but for imaging, the fewer times you touch the scope the better, IMO. Hopefully something pops up in a reasonable price range.
LOOK at JMI, I use this on my Edge HD Celestron, the only problem (which is why I made my own) with almost every focuser is that it is 100% ON, and has to be removed to use manual focus, where as mine you just slip the belt off, working on one for my celestron.
I did not see that one specifically, but I like the idea of either a stepper or a servo with encoder to make focus repeatable. The deepskydad one listed above looks interesting
I quite like the focusing that the auto focus does. And it only takes 3 mins to run. Takes me longer to do it manually. No backlash in my direct drive.
Cost
Stepper motor $25.
Flexible coupler $4.50
Motor bracket $5
Arduino $10
Stepper driver, a box and some leads and connectors, 3d printer filament - $20-30.
And a fun time designing and building it
Quote:
Originally Posted by glend
Guess I am a Luddite, as I am against them. I went through a phase of putting a motor on my TS APO, and letting SGP do the work but I was unhappy with both the outcome and the cost. I am trying to simplify my setup not make it more complicated. I found that often the SGP focus was not that sharp, and that my Batinhov mask gave much sharper results. Motorised focusers also waste a fair amount of imaging time and are another thing that requires power, cable management, etc.
For my setup, where I have matched filters, which are parfocal, switching them on the wheel does not alter focus in the image file. I can start a run and come back a couple of hours later and the focus is still perfect. I rarely bother checking anymore.
But hey, give it a go, if you don't mind the hassle.
Two caveats to note: you must have an excellent imaging capable focuser on your scope, which will not slip, twist, etc; and your equipment must be at equilibrium (adequately temperature adjusted). Scopes with poor focusers would obviously benefit from SGP focus checking.
Hi all just ordered the DeepSkyDad AF2 with all the bells and whistles for $308 posted can't wait to get it should be here in around 3 - 4 weeks from Slovenia
the fella that manufactures these units is very helpful and keen to provide a good service anyway when it arrives i will give a small review on it
cheers Pete
Hi Spiezzy,
Congrats, please let us know how it goes as the DSD AF2 certainly looks like a good option.
Quote:
Originally Posted by spiezzy
Hi all just ordered the DeepSkyDad AF2 with all the bells and whistles for $308 posted can't wait to get it should be here in around 3 - 4 weeks from Slovenia
the fella that manufactures these units is very helpful and keen to provide a good service anyway when it arrives i will give a small review on it
cheers Pete
Hi all just ordered the DeepSkyDad AF2 with all the bells and whistles for $308 posted can't wait to get it should be here in around 3 - 4 weeks from Slovenia
the fella that manufactures these units is very helpful and keen to provide a good service anyway when it arrives i will give a small review on it
cheers Pete
Can it be instantly dis-engaged for manual focus when needed
Hi Jeremy,
I agree being able to manual focus is an important consideration for many of us. That’s why I particularly like the steppers used by Avalon Instruments that enable manual focus when not powered: http://www.avalon-instruments.com/pr...e-focuser-focs
Quote:
Originally Posted by Ukastronomer
Can it be instantly dis-engaged for manual focus when needed
Hi Jeremy,
I agree being able to manual focus is an important consideration for many of us. That’s why I particularly like the steppers used by Avalon Instruments that enable manual focus when not powered: http://www.avalon-instruments.com/pr...e-focuser-focs
The problem with some is that they are permanent, with the one I designed for my scope the belt comes off in a second, I made the mistake of getting this for my Edge HD and it is not used
Ok I give in ... will buy one from TS for my focuser. The focusser is all set with a toothed gear for a belt drive and a slip clutch so manual focussing is still possible.
