AP setup help requested!

[buikimaging]

Hello all,

I finally have the funds to start setting up an astrophotography dedicated setup, however I am still a long way from making my decision.

So far I know with deep sky AP, aperture is not important, F number and focus length however is.

I am looking at a HEQ5 for the mount, with EQdir and stellarium and my modified guider/finder scope with webcam as I used earlier on my brothers setup.

However I am still very confused on the scope itself.

I heard great things of triplet APO's for beginners in AP so I was looking at some myself.

There are more than I expected so the question is: which of the triplet APO's fits more to my needs: wide field with the ability to capture some large galaxies?

I have calculated the FOV with a popular FOV calculator however I noticed that a 80mm gives a rather... VERY wide field leaving no room for any galaxies or clusters.

The 102mm option however is a lot more expensive and heavier and also larger, leaving more for the winds to play with (we are often plagued by winds with the 200mm PDS we are now imaging with)

Would the 80mm triplet APO be more in my favor?

I've seen some great APO's like Explore Scientific's 80mm ED triplet APO which would be the full set including case, flattner, diagonal.

The skywatcher 80ED's and 100ED's (not triplets however?) And Kson 102mm carbon ones.

There is also the possibility of getting the 100mm ES ED triplet APO but I would have to lose the flattner, diagonal and the case.

What would be your advice with a $1000 budget for an APO scope?

Any advice and tips are welcome!

[wxsatuser]

Hello all,

I finally have the funds to start setting up an astrophotography dedicated setup, however I am still a long way from making my decision.

So far I know with deep sky AP, aperture is not important, F number and focus length however is.

Aperture is important.

A 102 mm scope gathers 1.6x the light of an 80mm scope.

Your 200PDS gathers nearly 4x the light of a 102mm scope.

[ronin]

Aperture is important.

A 102 mm scope gathers 1.6x the light of an 80mm scope.

Your 200PDS gathers nearly 4x the light of a 102mm scope.

From a visual yes but on AP it is less relevant, an f/5 80mm apo gives a brighter image then an f/6 200PDS. The f/6 200PDS also will need a better mount owing to the focal length of the scope as any tracking errors are exaggerated by the focal length. Consider the simple action that a 127 SCT or Mak is a scope that is not recommended for any form of DSO AP. :grin:  Strange world of AP. :eek:

If the scope is for AP then from a search recently for something I found these: http://www.robtics.nl/index.php?cPath=21_23_91

They have a GTF81 advertised at in effect 1000€.

The addition of the inbuilt reducer makes the scope a bit slower then the standard GT81.

I would suggest that you contact them by phone as it seems a little unusual that they have one/any for sale.

Other then that as you say there are the TS scopes and ES scopes that are triplet and will fall into the budget. Do not think that APM, TMB, Taks and TV do.

The ES 80mm Essential gets good reports.

TS have their Photoline triplets with FPL-53, you have a choice of 2" or 3" crayford focusers, both costing less then 1000€.

http://www.teleskop-express.de/shop/index.php/cat/c223_APO-Refraktor-Teleskope.html

[D4N]

You could go for a small quadruplet instead, then you won't have the headache of flattener spacings.

As mentioned above TS do a line in these that are well within your budget.

You could also skip the diagonal if you are only going to image with it and use your Newt for visual.

What camera do you intend to use? This will have a huge effect on your final images.

Sent from my iPad using Tapatalk

[buikimaging]

You could go for a small quadruplet instead, then you won't have the headache of flattener spacings.

As mentioned above TS do a line in these that are well within your budget.

You could also skip the diagonal if you are only going to image with it and use your Newt for visual.

What camera do you intend to use? This will have a huge effect on your final images.

Sent from my iPad using Tapatalk

I will be imaging with my DSLR, later, when the funds allow it, make the step into the CCD world. But that's not in the foreseeable future since I will be going to college I won't have much time to work so the saving will take a while (man those things are expensive)

[buikimaging]

From a visual yes but on AP it is less relevant, an f/5 80mm apo gives a brighter image then an f/6 200PDS. The f/6 200PDS also will need a better mount owing to the focal length of the scope as any tracking errors are exaggerated by the focal length. Consider the simple action that a 127 SCT or Mak is a scope that is not recommended for any form of DSO AP. :grin: Strange world of AP. :eek:

If the scope is for AP then from a search recently for something I found these: http://www.robtics.nl/index.php?cPath=21_23_91

They have a GTF81 advertised at in effect 1000€.

The addition of the inbuilt reducer makes the scope a bit slower then the standard GT81.

I would suggest that you contact them by phone as it seems a little unusual that they have one/any for sale.

Other then that as you say there are the TS scopes and ES scopes that are triplet and will fall into the budget. Do not think that APM, TMB, Taks and TV do.

The ES 80mm Essential gets good reports.

TS have their Photoline triplets with FPL-53, you have a choice of 2" or 3" crayford focusers, both costing less then 1000€.

http://www.teleskop-express.de/shop/index.php/cat/c223_APO-Refraktor-Teleskope.html

That one I was indeed also considering, I had no clue the GTF had an built in flattner and I will definitely take a peek into that, I will be ordering from Robtics indeed, so far nice people so I will have to inform them for the availability of that scope.

Is WO any good in terms of quality and optics?

This is a first for an APO so I have no clue myself actually. That WO has FLP53 glass and heard good things about that.

The quadruplets would be very expensive and hard to get by here, they only start at $2000+ at 100mm so they will be out of the question.

[buikimaging]

After I have contacted my local dealer and got some advice on the telescope they refered me to a Skywatcher Esprit 80mm F5 Super APO with some extra bits and what not.

However that Skywatcher is almost a good €300 more expensive with little things I won't be using, is the Skywatcher optically any better than the W.O GTF80 at a longer f6.6?

I should really save up longer if I know the optics of the SW are much better.

Does anyone have any experience with the WO GTF having focuser issues as my dealer described? I read somewhere they fixed that by using a P & R instead of a Crawford one.

So all that remains: optics of the SW better than the WO or not?