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Jupiter 05 April 20:33UT

cgarry

By cgarry
in Imaging - Planetary

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cgarry

cgarry

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This is my first Jupiter image this season.  I have tried imaging it on a few occasions but the seeing was always so poor that I ended up deleting all the captured data without ever completing an image.  Last night the seeing was good for a change so I took the chance to see what the new ASI174MM could do while Jupiter is still around.

This is the image I came up with.  As ever I am not completely happy with the result, but I will keep this data and probably have another at some other time.

16438588433_e2ae3c2894_o_d.png

Cheers,

Chris

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Alan

Alan

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Good detail Chris and also good to see that you have eventually found some steady seeing.  I know just how frustrating it can be as I've had a bad Jupiter year too and only posted some half way decent images during the last few weeks. Let's hope for better things to come :)

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cgarry

cgarry

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Thanks for the comments.

Yes Alan, it has been very poor for imaging Jupiter this time round.  I guess that is just the way it goes and all of us UK based imagers have had to endure it.  Still it has been nice to have at least one decent night, even if the seeing did not last long enough to capture the more 'interesting' side of Jupiter.

Great shot Chris. Loving the colours!

P.S. Did you ever sort that Edge 14" out? I know you were having problems!

Regards

Harvey

I did get on top of the Edge 14"'s issues in the end.  The problems were down to thermal currents, thermal currents and more thermal currents!  The constant star testing was a real hassle at the time but it was the only sensible way to figure out what is going on and the diagnostic skills learnt are always good to have.

I have an old, non-edge, C14 now.  The advantage of this version is I can use a Lymax SCT cooler for initial temperature equalisation as there is no corrector lens blocking the baffle.  This set up works really well and I can take the scope outside and have it thermal free in an hour.

Cheers,

Chris

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Virgoman

Virgoman

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An excellent detailed image Chris! :smiley:

                          Best regards,

                                                  Ralph

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Barv

Barv

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Thanks for the comments.

Yes Alan, it has been very poor for imaging Jupiter this time round.  I guess that is just the way it goes and all of us UK based imagers have had to endure it.  Still it has been nice to have at least one decent night, even if the seeing did not last long enough to capture the more 'interesting' side of Jupiter.

I did get on top of the Edge 14"'s issues in the end.  The problems were down to thermal currents, thermal currents and more thermal currents!  The constant star testing was a real hassle at the time but it was the only sensible way to figure out what is going on and the diagnostic skills learnt are always good to have.

I have an old, non-edge, C14 now.  The advantage of this version is I can use a Lymax SCT cooler for initial temperature equalisation as there is no corrector lens blocking the baffle.  This set up works really well and I can take the scope outside and have it thermal free in an hour.

Cheers,

Chris

Thanks Chris.

The reason I asked is that I have an edge 14 too. I have been having the same problems but am slowly getting on top of it all now. I don't seem to be able to pull the same detail  as I did with my C11 Edge? Really strange. I wonder if I've got a dud one? I've lagged the tube with loft insulation and am pumping outside air in to the filter outlets at a hell of a rate and things have improved, but still not as good as I would have expected?

Regards

Harvey

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cgarry

cgarry

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I would be over the moon, if I

could get a picture like that.

Why do you think the C14 Edge,

suffered from, thermal currents.

I have got the C8 Edge.Seems

ok.Might be the size of the mirror.

Steve.

Diagnosing thermal currents is actually easy, you just do a defocused star test and you can actually see the currents flowing around the tube and boundary layers detaching from the mirror.  I doubt your C8 edge will suffer from this problem as there is an awful lot less glass and a much smaller volume for currents to form in.  I certainly never had any issues with my C9.25.

It was only after getting my C14 and doing some research that I found out that C14 owners were going to great lengths to remove thermal currents.

Cheers,

Chris

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cgarry

cgarry

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Thanks Chris.

The reason I asked is that I have an edge 14 too. I have been having the same problems but am slowly getting on top of it all now. I don't seem to be able to pull the same detail  as I did with my C11 Edge? Really strange. I wonder if I've got a dud one? I've lagged the tube with loft insulation and am pumping outside air in to the filter outlets at a hell of a rate and things have improved, but still not as good as I would have expected?

Regards

Harvey

I had exactly the same adventure I think, I could not get results as good as I was getting with my C9.25.  Once I learnt to do a star test and could objectively tell if I had thermal currents rather than bad seeing I was able to work through the issues one by one.  Forced air cooling of some sort is definitely a great way to go as is wrapping the OTA with some kind of thermal blanket.  However, sometimes the currents seem to come back and the forced air cooling needs to be repeated and this is a lot easier with a standard C14 and an SCT cooler...

I found on several occasions that currents were starting up that I could not account for.  Finally I realised the currents were actually in the dew shield.  My solution to this was to make my own custom dew shield which did an amazing job of solving this:

post-9259-0-68935700-1428524324_thumb.jp

I was also convinced that I had a dud C14 edge.  I had Celestron involved and then an optical engineer friend tested the optics on a bench and confirmed that the optics were actually excellent.  I very much doubt that your C14 is a dud, they just take a lot of effort to get them working well and they do also require better seeing to produce results obviously better than the smaller OTAs.

Cheers,

Chris

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Barv

Barv

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This is very interesting Chris. I think you are right. I wondered about the dew shield too so removed it on the last imaging session. I must admit this did seem to help some what. Even though I've done all of the below and flocked the tube I am still getting the blasted currents! Was your optical expert Es? I know him very well and I may get him to check mine. Although it probably isn't necessary.

post-32779-0-98408500-1428691027.jpg

post-32779-0-14996100-1428691160.jpg

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cgarry

cgarry

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Yes it was Es who checked the scope over for me.  I love the look of your solution, very space age!  It is a shame it doesn't solve the thermal currents.

You could always consider something like this: https://starizona.com/acb/Cool-Edge---SCT-Cooler---14-P3386C109.aspx

I know another C14 owner who has small fans fitted inside the OTA in the space in front of and to the side of the mirror.  These do a good job of preventing thermal current forming I am told.  I am thinking of doing something similar myself as well as fitting fans in the back of the OTA.

Cheers,

Chris

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Barv

Barv

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Yes it was Es who checked the scope over for me.  I love the look of your solution, very space age!  It is a shame it doesn't solve the thermal currents.

You could always consider something like this: https://starizona.com/acb/Cool-Edge---SCT-Cooler---14-P3386C109.aspx

I know another C14 owner who has small fans fitted inside the OTA in the space in front of and to the side of the mirror.  These do a good job of preventing thermal current forming I am told.  I am thinking of doing something similar myself as well as fitting fans in the back of the OTA.

Cheers,

Chris

As I'm sure you know Es is a top man and a great find! My solution is kinda working but Hey, that Starizona thing is a find, - I never knew it existed despite lots of searching. I'll buy one and see if things improve! Cheers for that Chris! Not sure about weather I could get the fans in there without interfering with the light path. Not a lot of room unless the tube is cut open. At 6K a pop I think this is a last resort!

Regards

Harvey

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cgarry

cgarry

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As I'm sure you know Es is a top man and a great find! My solution is kinda working but Hey, that Starizona thing is a find, - I never knew it existed despite lots of searching. I'll buy one and see if things improve! Cheers for that Chris! Not sure about weather I could get the fans in there without interfering with the light path. Not a lot of room unless the tube is cut open. At 6K a pop I think this is a last resort!

Regards

Harvey

Yes, Es is indeed a top guy.  Part of the reason for buying a cheap (relatively!) second hand C14, was that I wanted a scope that I could modify without crying about the loss of value I have caused!

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cgarry

cgarry

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Okay, time for the obligatory reprocess as I have been unable to get any fresh quality data!  I am really struggling with setting the colour saturation as all web browsers on my main machine display the image as very pale, yet PS and Windows Photo Viewer display it is as very vibrant.  Not too mention that the uploaded version looks really different on each computer I try.

Here is the reprocessed version anyway:

post-9259-0-95303300-1428708662.png

I am trying to achieve a more natural feel whilst preserving the detail.  Not sure if I have achieved this, but this version does at least handle a little enlargement which the first version did not handle at all well.

Cheers,

Chris

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Barv

Barv

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Well I like that Chris and I think you've done what you've set out to do. Looks really natural with all the polar detail there that can be there with typical UK seeing. I prefer this to the first!

Regards

Harvey

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cgarry

cgarry

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Thanks Harvey, I am pleased to at least get one image of Jupiter this time around.  Due to my imaging processes being a bit rusty I forgot to check scope collimation before capturing the data, which was a shame as it turned out to quite obviously out of collimation when I checked it.  Not a problem though, I just need to wait for the next night with great seeing in the near future!

Cheers,

Chris

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cgarry

cgarry

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Thanks Ralph.  Yes, let's hope we do get some more nights with good seeing before Jove is gone again.  It doesn't look like it is likely to happen in the next few days though...

Cheers,

Chris

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