RyanParle

Thanks Ole, My guiding has been pretty good since giving the mount a tune up & belt mod back in Feb. I am typically seeing an RMS of 0.2-0.3 arc seconds and a peak of around 1.5 arc seconds My image scale is 1.76 Arc seconds / pixel so i am happy that the stars stay on the same pixel for the whole exposure. I may grab a load of shorter subs tonight if i decide to get more data on M81 & M82, I'm not sure that i'll stop using darks though, I have a pretty extensive library of dark frames containing 60, 120, 240, 300, 600, 900, 1200, 1500 & 1800 seconds, each of those is split in to different temperatures from 5 degrees C up to 25 degrees C in 5 degree increments and each group has a minimum of 25 individual darks, add to this the Bias frames & Flat Frames for every 45 degree of rotator movement bringing the grand total of all calibration frames up to around 1400, of course these have now been replaced by master files to save time & disk space. So I pretty much have a set of calibration frames for any temperature, exposure or rotator angle I may wish to use. You're right about imaging without a flattener, I never got around to buying one, and probably wont bother for this OTA, I'll be getting a Officina Stellare RH Veloce 200 MK2 AT some time this year, considering that it will be around the same focal length but MUCH faster at f/3 it will make the APO some what obsolete!

Thanks Alan, I've got another thread about the lens correction stuff where I am looking in to creating a custom Lens Profile for my APO. Here:

Ive recently started a little Imaging again after a few years away from the hobby. Back at the end of Feb I spent a few nights re acquainting myself with my kit and getting everything set up and working reliably, i took a few test images of the flame & horsehead nebulae as well as a few sample subs of M81 & M82, since then I have changed my light pollution filter to an IDAS D1 and on Wednesday night I had the opportunity to set up an get a solid night of imaging, I ended up with 24 subs of 15 minutes shot with my EOS 50d (unmodified) on my ED80 refractor, a few subs were discarded due to guiding hiccups, passing aircraft & satellites but most of the data was good and the highest quality i have managed to date. My Processing could probably do with some more practice as there was much more detail within the spiral arms of M81 which I couldn't bring out without messing up the background of the image, but here is my best attempt so far: I have used the Photoshop Lens Correction tool in manual mode to try and improve the stars on the edges of the field, but couldn't get away with much correction as it was messing up the middle portion of the Image. Last night I also got an additional 12 subs of 30 minutes I'm currently working on adding this data in to my image, I'm not really sure of the best way do do so, Would it be best to combine all the data in one hit with Maxim DL and process as normal in photoshop or combine the two sets of data separately in Maxim DL then bring them together in Photoshop? I feel that the data is similar enough in both sets that combining it all as one dataset would work ok, as maxim has floating point image depth it should cope with the dynamic range ok. Any comments or critique on the above image or advice on how to combine the two data sets would be greatly appreciated.

For some time i have been thinking of having a mini pc based system for driving my imaging rig, and recently saw the Primaluce Lab Eagle3 devices which look pretty good, i like that they have the power control features and that they have not tried to add stuff like focuser and rotator control as i prefer to use my existing controllers for those features. However the cost of the Eagle3 Pro with i5 cpu 16GB RAM & 500GB SSD is around £1700 and you can get a Nuc or similar with an i7 CPU, 16GB RAM & 500GB SSD for around £700-800. would you guys say that the pre installed software, power control features, PLUS mounting solution and the sleek anodized red casing (I appreciate aesthetics too) is worth the extra money? If i bought the Eagle3 I would also buy the ECCO sensor unit for intelligent dew heater control, but there are other solutions such as the Kendrick dew controllers or an arduino could do the job quite easily.