Sky-Watcher Evostar 72ED DS-Pro

[Adam J]

On 13/11/2018 at 19:27, Thalestris24 said:

Hi

Can someone kindly tell me how much just the evostar 72ed ota actually weighs (with or without tube rings)?

Oh, and how good/bad the colour correction is when imaging.

Also, has anyone compared it with the TS carbon tube 70ed? 

Thanks

Louise  

A friend got the TS carbon tube ED and I can tell you that the CA is horrendous. 

[Thalestris24]

13 minutes ago, Adam J said:

A friend got the TS carbon tube ED and I can tell you that the CA is horrendous. 

Hi Adam and thanks

I think there are two versions of objective glass? Presumably the newer one that TS stocks currently is better than the older FK61 one? In any case, I've abandoned the idea for now, though I might still get an asi178mc and use it with an existing scope

Louise

[Stu]

26 minutes ago, Adam J said:

A friend got the TS carbon tube ED and I can tell you that the CA is horrendous. 

That's interesting. Is that 'horrendous' from an imaging perspective? My TS72mm is very good for colour correction but is fpl53 not 51 glass.

[Adam J]

Are we talking about this one? 

https://www.teleskop-express.de/shop/product_info.php/info/p1151_TS-Optics-70mm-f-6-ED-APO-Refraktor-mit-Carbon-Tubus.html

This was a year or two back and it may have been the older glass with FK61. However the one I linked is not fpl53. Am not convinced fpl51 is much better than FK61. I imagine you would still get some CA if the ZS71 is anything to go by. 

Edited November 28, 2018 by Adam J

[alexbb]

I plate solved an image taken with the ovl non reducing flattener. Focal length turned out at about 431-432mm. I can easily think of at least one other 72mm scope advertised at 432mm focal length.

[gary1968]

I had decided on this scope and dedicated flattener but this thread has put me off a bit.

Was the problem ever resolved, and if so how?

 

Gaz

[Shelster1973]

Am contemplating getting one of these. Would be used on my EQ6R-Pro and also wanting to try it on my Star Adventurer as plan on taking it to Cyprus in June next year.

Is the flattener essential for imaging?  Images on this will be with my D7100 which has a sensor size of 6000 x 4000 pixels (3.92 um size) when in standard mode or 4494 x 3000 if using the 1.3 crop mode.

[alexbb]

You'll need a flattener too. Be it the SkyWatcher one or the OVL. The backfocus spacing is a bit more than 55mm with both, I found it acceptable with the SkyWatcher reducer at ~60mm.

[Shelster1973]

Ok thanks for the info.

can see on FLO site that the ED72 flattener has quite a long lead time, yet says that it iOS essentially the ED80 with an adaptor and that far lattener shows as being readily available, so may go for that one.

[alexbb]

12 minutes ago, Shelster1973 said:

Ok thanks for the info.

can see on FLO site that the ED72 flattener has quite a long lead time, yet says that it iOS essentially the ED80 with an adaptor and that far lattener shows as being readily available, so may go for that one.

Yes, just that the "72" one has an extra threaded adapter. I believe FLO offered an adapter for the 80, one that you insert in the focuser, not a threaded one.

Edited December 24, 2018 by moise212

[Shelster1973]

Will give them a shout after Christmas and see what they have in that works. 

Mine advantage of living where I do is in am only 40 mins away from FLO so can get this sorted nice and easy. 

Also need to get a new piece for my filter wheel so can kill 3 birds with one stone

[simmo39]

Hi all, Im thinking of getting a SW 72ED pro to complement my SW 130 pds. The one thing that is giving me food for thought is the back focus. Can anyone confirm that with the SW reducer/flattener that I would be able to get focus using my ZWO asi 1600mmc and filter wheel. If it is possible how much back focus do i have left and is it an issue?

Also what if it is possible what spacing is it the reducer from the sensor? is it 55mm.

Oh and another thing! lol. What length Of Dovetail bar do I need to help balance?

Thanks in advance.

Simmo

[Stub Mandrel]

The ED66 makes a nice complement to the 130P-DS with its wider field but similar f-ratio making them similar to use.

[alexbb]

At about 60mm backfocus I managed to get this

But I remember I read somewhere that the TS flattener fits better and performs better. Can't say where I read that, maybe even on this thread. Will look when I get back at the PC.

Edit: not sure if better, but it seems it fits inside the focuser which should help with the backfocus issues.

 

Edited January 10, 2019 by moise212

[simmo39]

2 hours ago, Stub Mandrel said:

The ED66 makes a nice complement to the 130P-DS with its wider field but similar f-ratio making them similar to use.

Thanks for the pointer.

 

2 hours ago, moise212 said:

At about 60mm backfocus I managed to get this

But I remember I read somewhere that the TS flattener fits better and performs better. Can't say where I read that, maybe even on this thread. Will look when I get back at the PC.

Hi, nice image, saw that in the other forum. I would like to have the reducer to cut down on sub lenght as i will be using NB filters. as long as I can get focus with the SW reducer and my filter wheel I will go with the Sw one, if not i will have to again at just flattners.

. 

[simmo39]

 

2 hours ago, moise212 said:

At about 60mm backfocus I managed to get this

But I remember I read somewhere that the TS flattener fits better and performs better. Can't say where I read that, maybe even on this thread. Will look when I get back at the PC.

BTW, witch TS flattner do you recomend? there seem to be a few to chose from.

 

[alexbb]

8 hours ago, simmo39 said:

BTW, witch TS flattner do you recomend? there seem to be a few to chose from.

I edited the post above, but I saw no pictures through it in the thread:

https://stargazerslounge.com/topic/319495-skywatcher-72ed-just-arrived/

 

At teleskop express, they recommend the TSRED279 and the backfocus is specified at 65mm. Maybe drop them an email and ask for more. How does the flattener attach? How does an image look?

[Susaron]

12 hours ago, simmo39 said:

Hi all, Im thinking of getting a SW 72ED pro to complement my SW 130 pds. The one thing that is giving me food for thought is the back focus. Can anyone confirm that with the SW reducer/flattener that I would be able to get focus using my ZWO asi 1600mmc and filter wheel. If it is possible how much back focus do i have left and is it an issue?

Also what if it is possible what spacing is it the reducer from the sensor? is it 55mm.

Oh and another thing! lol. What length Of Dovetail bar do I need to help balance?

Thanks in advance.

Simmo

Simmo I did use a 33cm dovetail to proper balance the QHY168C, I also piggy back mounted the 30mm guide tube to help. Even with that is very very close to limit, see the picture

[Susaron]

I also had to discard the SW reducer as I was not able to focus, due to the reducer thickness, then I went for the TS 0x79 using 65mm distance and it focus perfectly with both the IDAS and the Halpha filters.

The TS has a 2'' barrel and M48 thread for filter on the tube side so it fit better. I made the measurements in another comment in this same thread.

[simmo39]

4 hours ago, Susaron said:

Simmo I did use a 33cm dovetail to proper balance the QHY168C, I also piggy back mounted the 30mm guide tube to help. Even with that is very very close to limit, see the picture

Hi Susaron. Thanks for the reply, I know its a bit bigger but my guide scope is going to be the SW Startravel  80! My guide scope will be bigger than the ED72! The reason being its what I have at hand. I think if I mount it forword of the C of G I may get some sort of balance. As for the reducer if i can fit my ZWO filter wheel  and still give me the required 65mm I may try one. Once again thanks for the advice.

[Susaron]

Finally yesterday after waiting a lot, my ED72 saw first light, coupled with an Optolong L-pro filter and the TS x0.79. I did try M31 from Bortle 6-7 skies and quarter Moon.

The 65mm distance from flattener to the sensor proved to be OK. I will soon post the results.

 

[RayD]

41 minutes ago, Susaron said:

Finally yesterday after waiting a lot, my ED72 saw first light, coupled with an Optolong L-pro filter and the TS x0.79. I did try M31 from Bortle 6-7 skies and quarter Moon.

The 65mm distance from flattener to the sensor proved to be OK. I will soon post the results.

 

Great news!  Look forward to seeing the results.

[alexbb]

29 minutes ago, RayD said:

Great news!  Look forward to seeing the results.

Me too!

[Susaron]

For the record, yesterday I was not able to plate solve with APT, I did use a 332mm focal length (420 x 0.79). Today using ASPS it confirmed that the real focal length is 350mm so the TS reducer gives a x0.83 reduction when coupled with my QHY168C. Setting up in APT the 350mm the plate solving was done perfectly.

[Susaron]

Here it is, quick process of 25x300s subs taken with the QHY168C and the Optolong L-Pro filter at 30km south from Madrid downtown.