Sky-Watcher Evostar 72ED DS-Pro OTA

[alexbb]

I added a thin spacer that I got with my ASI1600 and I'm shooting now some pics of M53 and NGC5053, but it doesn't seem better. I will add pics after I process them.

[RayD]

9 hours ago, moise212 said:

I added a thin spacer that I got with my ASI1600 and I'm shooting now some pics of M53 and NGC5053, but it doesn't seem better. I will add pics after I process them.

What I do when trying to sort out spacing is add a thin one first, then a tick one (or additional thinner ones), then if the star shapes change to radial, half this amount, and then half again etc. until spot on. It is a bit tedious, but with a non-matched FF there isn't really any other way, especially with a camera like the ASI1600 which has a reasonably large sensor.

[alexbb]

27 minutes ago, RayD said:

What I do when trying to sort out spacing is add a thin one first, then a tick one (or additional thinner ones), then if the star shapes change to radial, half this amount, and then half again etc. until spot on. It is a bit tedious, but with a non-matched FF there isn't really any other way, especially with a camera like the ASI1600 which has a reasonably large sensor.

Thing is that I only have a single spacer. I did not receive the delrin set yet. I figured out during the weekend that the Orthodox Easter it's not on the same date as others'. I'll be waiting...

[RayD]

46 minutes ago, moise212 said:

Thing is that I only have a single spacer. I did not receive the delrin set yet. I figured out during the weekend that the Orthodox Easter it's not on the same date as others'. I'll be waiting...

Ah OK I see 

[alexbb]

Spacers received.

[RayD]

5 hours ago, moise212 said:

Spacers received.

Oooh good stuff.  

I have the OVL FF also now so will be trying this out with my DSLR and CCD also as soon as the skies clear.  In theory we should come up with similar requirements, so will be interesting to see.

[alexbb]

It seems that I have at least some tilt, perhaps due to the poor connection between the focuser and the flattener. I put the widest and the thinnest spacer on the flattener (I had to force them on the flattener, they are too tight) and it seemed OK-ish during daytime. The focus seems OK in the middle and on one side, but not on the other. I can't play too much with this setup as I have the other imaging setup aiming for ~1.3"/pixel and when I move around I disturb it.

Anyways, my first impression during daytime, it seemed that a bit over 1.5mm extra distance would do. I might be able during next days to confirm.

One more thing, the new SW dedicated FR/FF is supposed to have an M54 thread to fit directly on the focuser. Maybe a 2 inch compression ring M54 adapter could replace the crappy holder with its screws. It's definitely the worst part of this scope, really disappointing. I can't find information about it being an M54 at FLO, but teleskop-express says it's M54. https://www.teleskop-express.de/shop/product_info.php/language/en/info/p10542_Skywatcher-0-85x-Reduzierer-und-Korrektor-fuer-Evostar-ED72.html

I'm continuing to shoot this evening M53 and NGC5053 with the DSLR. I will have ~2-3 hours in the end.

[RayD]

2 hours ago, moise212 said:

It seems that I have at least some tilt, perhaps due to the poor connection between the focuser and the flattener. I put the widest and the thinnest spacer on the flattener (I had to force them on the flattener, they are too tight) and it seemed OK-ish during daytime. The focus seems OK in the middle and on one side, but not on the other. I can't play too much with this setup as I have the other imaging setup aiming for ~1.3"/pixel and when I move around I disturb it.

Anyways, my first impression during daytime, it seemed that a bit over 1.5mm extra distance would do. I might be able during next days to confirm.

One more thing, the new SW dedicated FR/FF is supposed to have an M54 thread to fit directly on the focuser. Maybe a 2 inch compression ring M54 adapter could replace the crappy holder with its screws. It's definitely the worst part of this scope, really disappointing. I can't find information about it being an M54 at FLO, but teleskop-express says it's M54. https://www.teleskop-express.de/shop/product_info.php/language/en/info/p10542_Skywatcher-0-85x-Reduzierer-und-Korrektor-fuer-Evostar-ED72.html

I'm continuing to shoot this evening M53 and NGC5053 with the DSLR. I will have ~2-3 hours in the end.

Great stuff, thanks for the feedback.  Yes I agree with the screw fit, not the best.  However, I'm not sure it is a standard M54 thread, as has been discussed on another thread, as I tried my TAK fittings in it, which are M54, and they didn't work.  I am hoping that FLO may be able to supply a custom adaptor for it as I would certainly prefer a screwed fit, but if the SW FF is coming with the screw adaptor then this will be ideal as it will fit perfectly.

[alexbb]

I'm shooting some darks now, I will integrate all the subs tomorrow.

Meanwhile, crops from the corners and M53. 90s, ISO400. White balanced, stretched just a bit.

[alexbb]

Another preview

[alexbb]

OK, one more nigh. So 3 more hours. 6 will be then in total. I increased the dither, I hope the walking noise will fade away.

I should process the result tomorrow or Saturday, it takes me more than an hour to calibrate, register, normalize and integrate 120 subs in APP.

[FLO]

22 hours ago, RayD said:

I am hoping that FLO may be able to supply a custom adaptor for it as I would certainly prefer a screwed fit...

They are in the pipeline, hopefully not long now... 

Steve  

[alexbb]

2 minutes ago, FLO said:

They are in the pipeline, hopefully not long now... 

Steve  

I want already to place a pre-order for the FR/FF. Do you have an estimate for when the custom adapter will become available so I can order them both?

[RayD]

3 minutes ago, FLO said:

They are in the pipeline, hopefully not long now... 

Steve  

Great news, thanks Steve.

[FLO]

2 minutes ago, moise212 said:

I want already to place a pre-order for the FR/FF. Do you have an estimate for when the custom adapter will become available so I can order them both?

Not sure but will request an ETA when at my desk tomorrow. 

HTH

[alexbb]

Got some time to process the image. Here it is:

[Ben the Ignorant]

The glob is neatly resolved for a short-focal scope of such small diameter at prime focus. Faint stars are very fine, and brighter ones have well-differenciated colors, plus the halos around those brighter ones don't bleed smudges or spikes. This new 72 proves to be a very nice little scope for not much money.

[Stub Mandrel]

Very nice, I think you might benefit from playing with the bottom end of the curve for the blue channel to get rid of that faint streaking.

[alexbb]

I couldn't see the background that well, it was very sunny outside today and so was inside the room. I fixed the background saturation now, but the image was intended more to demonstrate the scope/flattener capabilities. I didn't put too much effort into imaging with this scope.

I'm waiting for the dedicated flattener and reducer, I hope the combination will work at least this good and the F/5 looks more appealing for a DSLR. I think the scope will then get more usage, especially when traveling light. 360mm of FL and a DSLR should be well within EQ5's guiding capabilities.

Edit: I should have mentioned. The image is made of 211x90s, ISO400, Canon 550D. Sky quality ~19mag.

[calli]

I still wonder how bad the field would look like without a flattener?

Cheers,

Carsten

[alexbb]

On 4/12/2018 at 23:41, FLO said:

Not sure but will request an ETA when at my desk tomorrow. 

HTH

Good morning, Steve!

Do you have any news about this?

[FLO]

2 hours ago, moise212 said:

Do you have any news about this?

Apologies for being vague, it is proving rather difficult to obtain an ETA. Reading between the lines I think the success of this model (first batch sold out in only days!) has taken them by surprise. 

From what we are hearing the next batch will arrive sometime in June but we cannot be certain. 

The importer assures us the next batch will be larger than the first but I am becoming concerned they might be sold out before they arrive! 

Please don't shoot the messenger 

Steve 

[alexbb]

10 minutes ago, FLO said:

Apologies for being vague, it is proving rather difficult to obtain an ETA. Reading between the lines I think the success of this model (first batch sold out in only days!) has taken them by surprise. 

From what we are hearing the next batch will arrive sometime in June but we cannot be certain. 

The importer assures us the next batch will be larger than the first but I am becoming concerned they might be sold out before they arrive! 

Please don't shoot the messenger 

Steve 

Maybe I also was a bit vague. Just to be sure, it's the custom adapter to a 2" compression ring I'm talking about.

Isn't this one a FLO custom one?

[FLO]

1 hour ago, moise212 said:

Maybe I also was a bit vague. Just to be sure, it's the custom adapter to a 2" compression ring I'm talking about.

Isn't this one a FLO custom one?

Ah, sorry, I thought we were talking about the telescope 

Regarding the 2" compression-ring adapter, it is a FLO product. I just spoke with John (he makes the majority of FLO's adapters). He says he has the necessary material so they are probably about a month away, so mid-May. 

HTH, 

Steve 

[alexbb]

6 minutes ago, FLO said:

Ah, sorry, I thought we were talking about the telescope 

Regarding the 2" compression-ring adapter, it is a FLO product. I just spoke with John (he makes the majority of FLO's adapters). He says he has the necessary material so they are probably about a month away, so mid-May. 

HTH, 

Steve 

I will place then a pre-order for the SW FR/FF and will contact you for the adapter when available so you can send them both.

Many thanks!

Alex