Stars look ok?

[Adam J]

3 hours ago, Allinthehead said:

Ya i had another look and now it's clearly visible. i had convinced myself it was better. Question is, is it really a problem? I'll gather a decent amount of data and see how it looks, and maybe try with the 1600.

Only you can say if your happy with it.

But let me put it this way...I had chunks out of my stars of similar size to that on my 130PDS and so I took a hack saw to my focuser tube to fix it.

[alan potts]

Minor though it is I can see the same issue all through these shots, as you say a Flat Spot on the stars, a nice image of the M101 if I may say so.

Alan

[Allinthehead]

6 hours ago, alan potts said:

Minor though it is I can see the same issue all through these shots, as you say a Flat Spot on the stars, a nice image of the M101 if I may say so.

Alan

Thanks Alan. Would you consider it a fault with the scope or would you live with it?

[alan potts]

Personally I would like an Espirit scope probably the 100mm which I think you have, I would want it spot on, this is what they advertise comparable to more expensive marques, this is not in my opinion and should be better, so as I am a bit of a stick in the mud for quality, being a director responsible for this when I was working, it would not do for me at 1500 pounds.  Also you are a very fine imager and would always be looked at closely by up and coming imagers like myself and others. I personally wouls send it for checking with FLO's service.

Alan

[Allinthehead]

44 minutes ago, alan potts said:

Personally I would like an Espirit scope probably the 100mm which I think you have, I would want it spot on, this is what they advertise comparable to more expensive marques, this is not in my opinion and should be better, so as I am a bit of a stick in the mud for quality, being a director responsible for this when I was working, it would not do for me at 1500 pounds.  Also you are a very fine imager and would always be looked at closely by up and coming imagers like myself and others. I personally wouls send it for checking with FLO's service.

Alan

Food for thought Alan, and thank you for the kind words. Looks clear tonight for my first proper run with the new setup so i should have more to go on tomorrow.

[alan potts]

I got up at 2 this morning and looked out the window to a stunningly clear sky, thought very hard about going out, then got back in bed, not looking great here at the moment. The days are clear but clouding up with high cloud after about 7 o'clock most evenings, 30C at the moment.

Let have fingers crossed for tonight if only for you.

Alan

[Allinthehead]

2 hours ago, alan potts said:

I got up at 2 this morning and looked out the window to a stunningly clear sky, thought very hard about going out, then got back in bed, not looking great here at the moment. The days are clear but clouding up with high cloud after about 7 o'clock most evenings, 30C at the moment.

Let have fingers crossed for tonight if only for you.

Alan

That's exactly how the last few months has been for me, throw fog in to the mix too. Instead of your 30C we have about 14C here.

[Allinthehead]

Managed to get about 3 hours of subs on Saturday night. The stacked image looks good but that maybe because i imaged at both sides of the meridian.

Single sub 

[alan potts]

I feel looking at that in the same way as I did the other images I can't see the same minor defect, I know it was only very small, indeed some may not even see it, for me it was there but I can't detect it now. I wish I knew how to expand the images to really get into the stars and see it close up but for the moment I think these look nice.

[Allinthehead]

3 hours ago, alan potts said:

I feel looking at that in the same way as I did the other images I can't see the same minor defect, I know it was only very small, indeed some may not even see it, for me it was there but I can't detect it now. I wish I knew how to expand the images to really get into the stars and see it close up but for the moment I think these look nice.

Thanks Alan. I thought the same, nothing has changed since the last subs except rotating the camera.

This is the result of 3 hrs integration. Quite pleased.

[Adam J]

26 minutes ago, Allinthehead said:

Thanks Alan. I thought the same, nothing has changed since the last subs except rotating the camera.

This is the result of 3 hrs integration. Quite pleased.

 

Huum, how are you connecting the camera to the scope? How are you rotating it? 

Some of these rotators are not all they are cracked up to be and can induce variable tilt in different positions. 

It looks fine now. I might just tweak the flattner spacing ever so slightly but thats not an issue with the scope. 

Adam 

Edited May 7, 2019 by Adam J

[alan potts]

The only other thing and I am not having a laugh here, has the weather changed much, someone I recall was talking about pinched optics. In all seriousness here it has gone from 30 to 7C in 2 days.

Adam could have something, maybe leave it where it is. 

Alan

[Allinthehead]

3 hours ago, Adam J said:

Huum, how are you connecting the camera to the scope? How are you rotating it? 

Some of these rotators are not all they are cracked up to be and can induce variable tilt in different positions. 

It looks fine now. I might just tweak the flattner spacing ever so slightly but thats not an issue with the scope. 

Adam 

Using the rotator on the focuser. I really hope that's not the cause as it's one of things that annoyed me with the Tak, if you used the rotator it would throw out the collimation. An Oag connects directly to the flattener so threaded m48 i think.

3 hours ago, alan potts said:

The only other thing and I am not having a laugh here, has the weather changed much, someone I recall was talking about pinched optics. In all seriousness here it has gone from 30 to 7C in 2 days.

Adam could have something, maybe leave it where it is. 

Alan

Yes Alan it was at least 5 degrees C cooler on Saturday night. 

[alan potts]

Rather stating the obvious but maybe mark that position where the camera is and generally keep an eye on it. I know you, I and others didn't imagine the defect, something must have caused it, I rather fancy a quid on camera rotation even though I do consider the Espirit range a cut above most of the Chinese made optics. I had a couple of the refractors here and the rotation of the focuser was not all it couple be, same too on my couple of ED70mm not in the same league as Espirit I would have thought but I imagine we are talking about a very minor amount of out of alignment. It will be interesting to know the answer.

Alan

[Allinthehead]

Update on this. I tried again with the Asi 1600 and the stars look pretty good apart from slight elongation in the corners probably due to spacing. 

I moved the position of the rotator too which could rule out that being the issue. More tests to follow.