alan potts

17 hours ago, Rodd said:

Yes-get a new camera.  The 1600 sensor has microlensing artifacts around square stars. It sucks. The 2600 and 6200 do not suffer so

It really does detract from your fine work which is as good as anyone's on the site in my eye's. The 2600 appears to be a lovely camera, I would like one but they don't seem to be a free gift in Cornflakes as yet.

Alan

My first thought on these and other captures I think you posted last week are stunning shots ruined by square stars, I really could not put up with that from my work which is very second rate compared to yours. Can amything be done to stop it?

Alan

Olly,

Can't say I ever noticed it on the 12 inch with the Moonlite focuser made for the reducer hich I used for about 3 years or more. Can't double check it for you as someone is coming to buy it this morning. I would give that idea with the SC 2 inch back a try, the Moonlite is somewhat longer than say the Baader which I also had once.

Alan

Stunningly good Rodd,

Alan

On 03/11/2022 at 12:43, bomberbaz said:

It's a lovely image, wouldn't have noticed anything wrong with the stars had you not mentioned it.

No there's nothing wrong with the stars on this image Steve, it was with the reducer which I haven't used since I tried it out, think it just needs .3 or.5 shim in the mix even though the info clearly states 55mm, still it's not made by Tak so I can live with that.

Alan

I always wanted to try this wider field, even down to buying a .6 reducer for my 800mm scope. Sadly though even at 55mm spacing some fine tinkering is required as the stars are elliptical slightly at the corners. As always i just bunged it back in box and put it on the shelf. I finished this 5 hour run the other night before I managed to nearly kill myself with the handle of one of my axes, now have two purple eyes and 7 stitches in my forehead. So here's my Sh 2 171, as I say 5 hours and a bit sampled at 95%. 

Feel free to offer advice there will be plenty wrong I am sure.

Alan.

14 hours ago, MartinB said:

Very nice Alan, the dust is showing well.  As for separating the stars, if you have PI, PS or Affinity Photo you can use Russ Croman's StarXterminator.  It costs a few bob but well worth it.  Alternatively Starnet2 is also brilliant.  They are easy tools to use.

Martin easy to use for me is a must. I tend to do everything quick and to eye, I have an excellent eye of colour and general composition in photography in general, I know I am never going to compete with many on this site so don't try to. I am happy with my shots and that's the main thing to me. May look at one of the star removal systems though.

Alan

1 hour ago, Ouroboros said:

 I’m not sure I’ve got any advice, Alan. The cave nebula is a very faint object as I found a few weeks ago when I just had a go at it one night a few weeks ago.  It’s tricky to process.   As you say, it needs a lot of data. I certainly didn’t get enough. I’m not sure you have either. You’ve done a nice job of getting rid of noise in the background,  but then the nebulosity still looks grainy. And there’s the rub isn’t it? One can smooth the background but not the faint nebula without losing detail.

Your stars are nice and tight.  Did you use any star reduction? The image might benefit from a bit more.  Did you try separating stars from nebula and working on then separately? 

I understand what you are saying but in truth I don't know how to do this separating stars and nebula. I processed this in less than 5 minutes as I always do, I do very little to anything really, stretches and then sometimes selective colours boost. I may well add to it as I have a few clear night still before the Moon annoys me again. Anything I do that look decent is normally by accident. I tend to use Camera Raw Filter mostly as well as Select and Mask.

Alan

A good while ago Olly, who is known by most on here, posted advice along the lines of I use to take 3 images a night now I use 3 night for one image, it's always stuck in my mind and now do this. Last year i took a shot of this same subject and was fairly pleased with my 90min-2 hrs effort, i didn't realise how bad it was until I added another 7 hours of data. So heres a 90% selection of a total of about 9.5hrs taken over a year or so, still can't see a cave though.

Advice always welcome. Thanks for looking,

Alan

Maybe the best image I have seen this year, very well done.

Alan

Hi.

I don't know if you know him already but Danislav Kodzhabashev is involved with the local group in and around Sofia and probably know everyone in a 100klm radius that is into astronomy, I am some way from Sofia near Sevlievo and only rarely go to Sofia these days. I could check with him and message you his phone number if it was OK with him  if you want to meet like minded people.

Alan

Welcome Peter hope you enjoy the site.

Alan

Out of season maybe but as good as any I have seen, nicely done Sir.

Alan

How odd, I was looking at my very first image taken about 5 years back and it looks exactly the same as this one, maybe I had a bit more red. Nice start and keep it up.

Alan

I think that has come out rather nicely.

Alan

That's as good as any versions of this I have seen, really lovely colours.

Alan

35 minutes ago, Clarkey said:

Ok fair enough - could be a duff one? If is that bad I think you would be justified in sending it back.

I'll try it again, though I have only had it a short while I haven't been able to use for weather firstly and then I dislocated two fingers on my right hand (still affected) which hampered me doing a great deal. FLO being what they are I am sure will be understanding in the face of this. I dare say these laws on sales, which I don't entirely agree with, do not take into account that if in the UK you could be unable to try anything for many weeks. We had a terrible April and though May has been great I haven't Just able to try it the once so far.

Thanks for your help.

Alan

5 hours ago, Clarkey said:

I have the non-reducing flattener which is 'optimised' for DSLR but I am using it with a 1600MM pro. The 55mm is from the shoulder of the M42 or M48 adaptor. In theory the standard spacers for ZWO 55mm backfocus should work. I did have to add a couple of additional spacers to add about 1.5mm additional distance on mine - but other than that it works well. (Depending how fussy you are, it is not perfect in the corners - but pretty good).

Really, if that is the case then I did exactly what you have done without any additional shims. The affect I get is s little like stars all around edges that look like those from a reflector with spider vanes, absolutely unuseable as an image. I have to say though from memory the centre was not bad. No one would accept what I got as even half decent, it was rubbish and I have since dumped all data. If anything I was wondering if it could be pinched optics as at a quick glance I didn't see the fault. I do have some thin shims I could try to add. I don't have any luck at all with reducers, no matter what they cost, OK the scope is an F 7 APO but decent optics at the top end of the spec but it should be better than what I am getting, miles better.

Alan   

12 hours ago, symmetal said:

Optimised for DSLR just means it has a 55mm backfocus distance. Any sensor, DSLR or not, placed 55mm from the FF would be fine.

Using the 16.5 and 21mm spaces along with the camera's 17.5mm backfocus should give the 55mm required. Are you using a filter between the FF and the camera? The ASI071 response graph extends significantly into the IR with a similar response for RG and B beyond 800nm. It doesn't show the response of the protect glass, so there is no UV-IR cut filter in the way, which could lead to out of focus IR giving star bloating in all three colours.

So a UV-IR cut filter is needed somewhere, possibly screwed into the rear of the FF. Note that if the filter is between the FF and the camera you need to increase the above 55mm spacing by 1/3 the thickness of all the glass in the way. The camera  protect glass should be included here as well, so 56 to 56.5mm spacing is a better figure to use.

Alan

I have a UV/IR filter on the front of the reducer. The trouble with it is that the lenses that do the work are recessed into the housing. I must carefully try and measure it to see what it is. It may just be leave of the 16.5mm spacer, lets hope. I am not going to go to the trouble of finding other spacers, for what it cost I will just throw it in a draw and forget it, my fault for not reading it correctly.

Thanks for your input.

Alan

Bought one of these 0.6 reducers from FLO about two months back and like a moron didn't read the advert correctly. Optimised for DSLR's I see it states with a back focus of 55mm.

I banged in the normal 16.5mm and 21mm spacers and then wasted 4 hours of wonderful sky, returning rather odd shaped stars in all the frames. Does anyone know if this can be used on my Zwo 071 or is it for the bin as I will not return things that are my fault.

Alan

As good as any I have seen from a shorter focal length.

Alan

Never seen that one before and considering your conditions a great result!

Alan

Well that has come out a lot different to anything I get on a OSC and I think this is the best image I have seen of it, or at least the one that appeals to me the most. Cracking shot!!

Alan.

On 27/04/2022 at 08:39, wimvb said:

Thanks, Alan. I thought this might convince you. Go for it!

Be nice to see some clear sky at the moment, this time of year we often get sunny days and stormy evenings, as well as up and down weather in general, 27c yesterday 12c today

Alan

That is lovely, now what better reason for me to mount up my M/N 190.

Alan