Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.



  • Content Count

  • Joined

  • Last visited

Posts posted by Prolifics

  1. Thanks for the info. I will try longer exposure again. Having huge problems with all these Elon Musk satellites wizzing across my frames so thats why I shortened them. :)

    I am wondering how to get more colour in photshop do I increase the saturation?





  2. Hi I have uploaded my highest scoring Lum file from a couple of nights ago. There is some funny star shaped in it especially around the edges.

    I am using A TS 107 Triplet with a 2 inch TS optics 0.79 focal reducer. EFW filterwheel and a Zwo asi1600mm pro Cmos camera.

    By using the the adapters and adding them all up I get 56mm backfocus. According to this chart from TS Optics I need an extra 1mm.

    Information from them here....

    Back Focus - distances from the T2-thread to the camera sensor

    depends on the focal length of the telescope:

    ♦ Focal Length to 350 mm .... 70 mm
    ♦ Focal Length to 420 mm .... 65 mm
    ♦ Focal Length 450-500 mm ... 61 mm
    ♦ Focal Length 510-600 mm ... 58 mm
    ♦ Focal Length 610-700 mm ... 57 mm
    ♦ Focal Length 710-790 mm ... 56 mm
    ♦ Focal Length from 800 mm .. 55 mm

    My scope is 700mm So I am rigth on the end of one of those calculations.

    Today I stripped everything down and checked everythintg. I was using a 1.2mm washer to get the extra 1mm distance but the washer was a hard plastic type and when I measured the gap it was more than 2mm. 

    I managed to find some soft type washers in my old ZWO box remove the old one and put a thinner one in which is giving me around 0.9mm gap. Giving me a total of 56.9mm. Instead of 58.1mm

    Do you think that should fix the problem? Can 1.2mm out make my stars look like this or have I got another problem. Not had chance to take the scope out to test the new configuration due to the usual clouds.

    Any help would be great. Single frame is of M3.

    Thank you for any help in advance.






  3. It's all looking good! I appreciate the time you have put into this.


    Thank you for that. It was all about producing better and better images which has happened. But perfecting each thing you do is very time consuming :) This is why this hobby is so fantastic. I need to spend more time watching whats going on rather then spend lots of time setting up and then leaving it on a plan for several hours doing nothing.



  4. my scope is F6.5 or F5.13 with the focal reducer.

    I have the Pegusus power box so the dew heaters come on and off automatically when the due point gets near the temperature point. That would make a difference if the tube was getting slightly warmer by .5c would expand the tube?

    Maybe having the due heaters on all the time would be better when its cold outside?

    Regards David


    • Like 1

  5. 48 minutes ago, vlaiv said:

    Indeed. Flat darks are just darks for flats - same way you take darks for regular lights - you do the same for flats. Same exposure duration, same settings, everything the same as flats except you put scope cover on to block any light.

    Great all understood!


    I have had a look at all my frames and I do not see any out of focused doughnut stars. Maybe deepskystacker was the culprit? The HFD is between 0.50 and 1.37 for the whole starfield.


    Here is a sample of a frame.


    Regards David


  6. Hi Red Dwarf


    Thank you for all the information. I have taken in everything you have said and that all makes perfects sense. I guess that means all my RGB filters must be Par focal and my LUM not matching with them?
    Next time I will refocus for each filter that I use.

    I will try next outing to re-focus and use the magnifier in apt on the stars to make sure there is no circles and make sure they are solid and round not fuzzy.

    I am a bit confused with flat darks are these bias files? I will do a google search and research the flat/darks.

    I am really happy you brought these points up. This will make me move further forward in the right direction. I am quite new to Astro photography this is my 5th image. Althought I have been into astronmy for 4 decades :)

    So better focus and dark/flats next on the menu for me :)

    You have done a great job on the image can hardly wait for the colour version :)

    KIndest regards David


  7. Hi Geoff wow you don't messaround :)

    Not too hot with Photshop I coverted the files to 16 bit and then applied deep space noise reduction.

    Adjusted levels and curves bit by bit and then added a new layer and copied the RGB over and then added the LUm channel next to the background and adjusted to luminosity.


    Thats about as far as I got.


    Unfortunately I had some sort of image that I wasn't very happy with so quit photoshop.


    I really need to go on a course or something for post processing.


    Regards David


    • Like 1

  8. I took 

    60s x 90 Lum
    120s x 20 RG&B
    50 Flats & 50 Darks

    I have stacked the L R G and B data in deepsky stacker along with the darks and flats. But I don't seem to be getting much from the data via photoshop.

    I am wondering if the data was any good? Bortle 5 sky, good seeing and guiding was excellent last night.


    Files are located here https://www.dropbox.com/sh/rzkkbbbokj5fqei/AAAR-Jfsyvd3_6gDr3qGCyhwa?dl=0        if you fancy a play and can get anything with it.


    Kindest regards in advance David



    • Like 1

  9. Hi I use eqascom (eqmod) and APTEverything was working fine last time I set up.

    However when I slew to say Polaris it's not in APT live view window the RA is always 3.5 more on APT and EQmod then on the plate Solve coordinates. It will not synch either comes up with cannot syncg to coordinates exception occured.

    Using Astap here is the screen with Polaris centered. Platesolv RA and Dec is correct but APT and EQmod althought the same are not.


    Using Eq6 Pro and tried the hand controller and the direct Lynx astro cable and they are botht he same so ruels the cable out.


    Screen for reference. Ignore the ghosting in middle this is actually a large antenna in the way :)






    2020-03-22 (1).png

  10. 1 hour ago, alan4908 said:

    I had a look at your data and used Pixinsight and Photoshop to process the result (below). As you can see you've captured quite a lot of detail. 

    On the vignetting issue this seems to be mainly in the RGB data, your Lum data is much flatter. I eliminated both with the use of Pixinsight's DBE function - you can do a similar function in PS but you will require the use of the plug-in Gradient Xterminator. 

    I also noticed that your lum data is very slightly misaligned with the RGB data, so I realigned this to get better stellar profiles.




    Hi Alan thanks so much for doing that for me. It was the first time I used my scope with the focal reducer. I think stars are fairly round now. Use to be elongated near the edges. 

    Like I said flats didn't come out right on the night was very tired from 4.5 hours of data :) I tried taking the flats 3 weeks later and I think the issue with the fluffy bits is the reason. Not sure about the RGB data.

    Not sure why deep sky stacker does not align properly its like a little bit off any settings you recommend to fix that. I use one of the LUM lights best score for the Reference frame as i shot either side of the Meridian and I don't have a rotator installed.

    Kindest regards David


  11. 1 hour ago, wornish said:

    Thanks for sharing the data which is very good.  This was processed in APP ( integration) and PI (background removal)then tweaked in PS.


    I am certainly no expert but here is my attempt.

    OMG thats amazing you can really see the detail even in the little galaxy in the north west of picture. So at least my stacking is fine :)

    First thing I do in photshop is convert them all to 16 bit. LRGB

    Then I level and curve adjust them all several times until I get better details.

    Make a new layer and copy and paste the RGB data

    Then I add the lum to the same layer.

    Thats about as far as I got sometimes I play with saturation on the RGB too.


    Kindest regards David




    1 hour ago, wornish said:





  • Create New...

Important Information

By using this site, you agree to our Terms of Use.