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Posts posted by Uranium235

  1. 7 hours ago, Adam J said:

    sounds horrific.

    I get your point but at the same time the Daws limit of a 65mm aperture is about 1.8 arcsecond per pixel, while you can sample that, separation I doubt you would truly resolve anything down to 1.18 and so you can probably still make gains by resizing the image without losing much in terms of detail.


    Quite right, the camera is trying to image past what the actual optics can resolve with a 65mm aperture. Its much better suited to the 130pds - being just slightly oversampled, and you have 20MP to play with, so its quite possible to bin the image. Though if im not mistaken - its not true hardware binning with CMOS so the same effect can be achieved just by resizing with software.... which is handy becuase instead of cutting it to 5MP (as you would with 2x2bin), you could reduce by 0.5 instead and have a 10mp image to process.... which is still pretty big!

    Though the image is a good example of both what the telescope and camera can achieve.

    Just wait until galaxy season swings around, you can have some serious fun with the 130/183 combo ;)

  2. I might add that Im going to do the milkbottle washer mod for my secondary, I feel there is a little bit of rotation - perhaps indicated by the off centre illumination im getting in my flats  (which is slightly shifted to the right). The degree of adjustment required is small - hence the mod because it allows for very fine adjustments.

  3. Welcome aboard :)

    If youre waiting for a clear night, you can normally bank on it being on the night of a full Moon :D I think the sky does that sometimes just to rub it in.. "fine here you go, a night with no clouds - but im going to stick a really bright thing in the sky to blot everything else out"...lol.

    • Like 1

  4. On 16/02/2019 at 10:25, RolandKol said:

    Hi, do you use simple Cheshire for collimation?

    I struggle a bit with my secondary... My Cheshire is just a bit Wobbly in and results are bit "luck" dependant. :) 

    Mine is the combined cheshire/sight tube. If its a bit wobbly, then you could use a self centreing EP adaptor - but even those have a small degree of inaccuracy. You could also wrap a single  layer of tape around the cheshire EP, thats another way to make the fit  bit more snug.

    As long as your secondary is at the correct angle (appears round) and directly under the sight tube, then just follow the normal collimation steps.

    • Thanks 1

  5. 6 minutes ago, Davey-T said:

    I've got the Star71s on 11" dovetails pushed right forwards in the clamps on a dual bar.


    Yeah, same here - Ive got the long geoptik bar and a spare clamp I could rig up. 

    I reckon a really good match for the redcat would be an atik 490. 3" p/p and a more than useable fov. 

  6. 37 minutes ago, Davey-T said:

    S'long as it's not a QSI683 :D


    Lol... I was thinking of shifting the samyang 135 (again), no doubt I will probably end up buying another in 12 months time :D 

    Come to think of it - that qsi is a heavy lump of a camera, I would definitely need to sort out a longer dovetail for it to balance out correctly.

    But the winner for the redcat will be zero focuser slop - probably the single most common cause of a tilted field.

  7. 1 hour ago, Xiga said:


    I will give it one last go, with another step-down ring to stop it down a good bit further and see if things become acceptable. If not, i'll consign it to the dustbin and just save up for that Samyang 135mm F2. 

    Hmmm I wouldnt bin it per se. If you eventually get the Samyang, you could use the Tamron as a spare portrait lens.  You could even aattach an EP to a camera lens and use it as a monocular...lol :D  (if you have the right bits)

    • Like 1

  8. Personally, I'd go with the 130pds every time, it will be much easier on your guiding and gives you a much more compact setup.

    The 200pds imo is too much of a handfull, and takes some tweaking to get if in the right place with a larger sensor. Plus it's quite restrictive in terms of what you can image.

    The 150... hmmm it's fl is just a little too long for me. The 130 is 650mm, which is a good spot.

    Oh, and in regard to guiding. The 50mm finderguider is the most cost effective. Plus it never fails to find a star.

  9. The way I set mine up is I have a little acer aspire netbook (win xp) running the imaging and guiding. Then use powerline networking to control it from the living room using a gaming spec pc (ryzen 5, m2 ssd, gtx1060) that makes short work of any processing or stacking jobs.

    The data transfer rates over powerline networking are excellent, way better than WiFi.

    • Thanks 1

  10. 5 hours ago, clitherowclan1 said:

    Hi, I'm a newbie to the forum but saw this post about the 178 camera. Don't want to take it over but thought I might show an ASI178MM-Cool image taken last  night with a William Optics Star71mm at 350mm focal length; helps with an idea of field of view of this chip? For info, this is a stack of 18 guided images at 240 seconds per exposure, no darks, no flats.

    Hope that's of some interest,

    Alan C.

    Your image gives a good indication of what the raw uncalibrated data looks like - especially that starbust amp glow in the bottom left. Thats why calibration (with darks at least) is mandatory with this camera. Once fully calibrated you will be able to make much better use of the data you have there.

    One word of caution, if you have yet to take darks - do it roughly the same ambient outside temperature at which your L frames were taken. Thats why with this camera (as the seasons progress) I periodically dedicate the last hour of each imaging session to taking fresh darks. Theyre short subs, so it doesnt take long to build a half-decent stack.

  11. Great sky out there tonight :) Shame ive had to pack up at a sensible time!

    Its been my first decent go at imaging something for a couple of months, maybe more. But glad I took the time to set up. I wanted a quick start so I went light with the ASI and f2 lens, which seemed to frame the whole thing quite nicely!

    Ive managed to calibrate out the amp glow, and for just 135mm focal length - the result turned out better than I had expected :) 



    50x240 (Ha)

    ASI 178MM Cool, Samyang 135mm @f2, NEQ6

    Thanks for looking :)



    • Like 20

  12. Ok folks, its time for the 2018 showcase :) 

    Please use this thread to showcase your best images captured during 2018. Just one post per member but you can include up to 5 images if you want.

    The thread is for all imagers, both novices and advanced.

    Please keep details to a minimum - scope and camera possibly along with a few comments.

    The thread needs to be packed with images so please don't respond to the postings 

    • Like 3
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