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Astrophotography with an Astro-Tech-102ED

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4 replies to this topic

#1 Andre Moutinho

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Posted 30 June 2020 - 09:24 PM

Hello all,

 

Does anyone here have experience with the AT-102ED for astrophotography usage? I would be nice to see some pictures taken with this refractor.

 

Best,

Andre



#2 cst4

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Posted 30 June 2020 - 09:54 PM

Here’s a single 30 sec shot I took through my 102ED with my Sony a6000. It’s a great scope and with a nebula filter and some post editing is capable of some good AP shots. But still it’s not a true apo and your camera sensor will show it... bright stars have pink halos as you can see. Wonderful scope for visual use but you either need a triplet or FPL53 glass doublet to get more natural star color. The second shot was with a neb filter which turns stars bluish and hides the pink.

 

582A71A9-9C6F-4624-A64E-583717FED01B.jpeg

 

59388917-6171-457A-A581-B589919C4445.jpeg


Edited by cst4, 30 June 2020 - 09:57 PM.


#3 Andre Moutinho

Andre Moutinho

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Posted 30 June 2020 - 10:23 PM

Hi, thanks for your reply.

 

What nebula filter you recommend? What about narrowband astrophotography? Think it will give better results?

 

Here’s a single 30 sec shot I took through my 102ED with my Sony a6000. It’s a great scope and with a nebula filter and some post editing is capable of some good AP shots. But still it’s not a true apo and your camera sensor will show it... bright stars have pink halos as you can see. Wonderful scope for visual use but you either need a triplet or FPL53 glass doublet to get more natural star color. The second shot was with a neb filter which turns stars bluish and hides the pink.

 

attachicon.gif582A71A9-9C6F-4624-A64E-583717FED01B.jpeg

 

attachicon.gif59388917-6171-457A-A581-B589919C4445.jpeg



#4 cst4

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Posted 01 July 2020 - 02:36 PM

I will admit I do not know too much about astrophotography so I am not the best source on this subject.  I am mostly a visual observer but my AZ-GTi mount tracks well enough that I sometimes like to hook up my DSLR and try to capture a picture of what I am looking at.  That's how I obtained the pictures above.  I originally assumed you were considering getting an AT102ED for astrophotography but I see now from your signature that you already have one.  And you also have a couple of good mounts that should work for AP.  So my advice would be just to start trying it out and see if you like your results.  The 102ED is not the best for AP due to residual chromatic aberration but it can still work.  I bet there are some forums on here that have some info on how to do AP with an achromat.  Following those techniques would probably work well.  I bet you are correct that narrow band imaging would provide better results.  With an achromat or semi-apo like the 102ED all of the wavelengths of light do not focus to the same point and you see chromatic aberration, but if you could photograph just one color at a time then I don't think that would be an issue.  Even with narrowband filters, there is less overall light energy hitting the sensor and pink halos and such would likely be reduced or colored differently like in my second pic.  I do not know what filters would be best... again I'm sure there are some forums on here with that question answered.  The one I used in the picture above was just an older Orion UHC filter (made in Japan) that I purchased in the classifieds here for about $25.  I'm sure there are better ones out there but it provided the results that I wanted.  I also bet there are some good photoshop techniques that could help make your shots look more natural.  But even still, the 102ED can take pretty decent shots so you may be happy with it as it is.  Or it at least would be a great tool to learn on and maybe upgrade one day down the road to something more suited for AP.  Good luck in your endeavors!


Edited by cst4, 01 July 2020 - 02:41 PM.


#5 Andre Moutinho

Andre Moutinho

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Posted 03 July 2020 - 02:36 PM

I will admit I do not know too much about astrophotography so I am not the best source on this subject.  I am mostly a visual observer but my AZ-GTi mount tracks well enough that I sometimes like to hook up my DSLR and try to capture a picture of what I am looking at.  That's how I obtained the pictures above.  I originally assumed you were considering getting an AT102ED for astrophotography but I see now from your signature that you already have one.  And you also have a couple of good mounts that should work for AP.  So my advice would be just to start trying it out and see if you like your results.  The 102ED is not the best for AP due to residual chromatic aberration but it can still work.  I bet there are some forums on here that have some info on how to do AP with an achromat.  Following those techniques would probably work well.  I bet you are correct that narrow band imaging would provide better results.  With an achromat or semi-apo like the 102ED all of the wavelengths of light do not focus to the same point and you see chromatic aberration, but if you could photograph just one color at a time then I don't think that would be an issue.  Even with narrowband filters, there is less overall light energy hitting the sensor and pink halos and such would likely be reduced or colored differently like in my second pic.  I do not know what filters would be best... again I'm sure there are some forums on here with that question answered.  The one I used in the picture above was just an older Orion UHC filter (made in Japan) that I purchased in the classifieds here for about $25.  I'm sure there are better ones out there but it provided the results that I wanted.  I also bet there are some good photoshop techniques that could help make your shots look more natural.  But even still, the 102ED can take pretty decent shots so you may be happy with it as it is.  Or it at least would be a great tool to learn on and maybe upgrade one day down the road to something more suited for AP.  Good luck in your endeavors!

Hi, thanks a lot for you very detailed reply! it is very much appreciated!




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