alan potts

13 hours ago, atamuli said:

Hello Alan,

I am exactly facing the same issue. Would you please share the settings that you use in your dark and bias settings in DSS?

Thanks in Advance,

AT.

I am afraid I can't I have gone over to OSC Zwo camera now and have changed things a few times. I can't remember what I used other than in the setting there is an option of median with sigma clipping, I believe I used that. I am sure someone on here will have an answer for you. I may however be more useful to post an example and start a new thread, this one is rather old.

Alan

Best wishes to all of you, can I ask if you get time in the early New Year you could let us know what the situation is regarding orders from me and others abroad, if you haven't already and I've missed it.

Alan

John, better off than you for latitude by close on 10 degrees and I have done this many a time with the 115mm triplet and the 190mm M/N as well as my Dob, but if you can't see it with a quality 18 inch mirror then the conditions are dire, it has happened.

You may well remember some time back I played a game trying to see it from about you maximum latitude by estimating when it is the same amount of degrees above the horizon, result here are far for wonderful and compare much the same as your own, I don't recall seeing it below 20 degrees with the 115mm but have done with the 180mm Mak and 190mm M/N. I found a power around x150 best for me but there are so many differences between our two sites.

Best wishes for the New Year, lets hope it's a tad better than this one, Alan

2 hours ago, ollypenrice said:

Probably nothing to worry about, Alan. Our OAG guide graph at 2.4 metres FL looked Himalayan when it was presenting the trace in pixels. In fact it was running at about 0.3 arcsecs RMS which is brilliant. If you plug the guiding focal length (805mm) and the guide cam pixel size into PHD it will give you the guide value in arcseconds and you will probably be greatly reassured by this!

It won't do any harm to use an OAG. It's probably a good idea, but I guide my TEC140 (1015mm/0.9"PP) with a guidescope.

Olly

Yes of course I didn't change the guide scope focal length in PHD, so therefore I imagine the calibration would be wrong as well, so much to remember with this dark art, plus the grey matter is not what it once was. I was considering having a play with my 180mm Mak, even though it's F15 and I don't have a reducer I thought it may be good on globulars, well the brighter ones.

Alan

38 minutes ago, Hallingskies said:

The first time I used an OAG, I was also disappointed with the result.  However, I quickly traced it down to the fact that I hadn’t tightened down the height adjuster on my Atik OAG.  Results were a considerable improvement over a guidescope after that.  You’ve probably checked it all over three times already, but you need to make sure that everything in the imaging train really is rock solid.

Fairly sure I covered everything and I did tighten up the alen screws, however as I took things apart I thought there may have been some movement in the many rotating parts of the 3.7 inch focuser, I will continue to play with it over the coming months. I feel my biggest problem is I am always chopping and changing scopes and focal reducers, too much gear not enough clear sky.

Alan

I tried my OAG last night after about a year of being in the box, I also bought the focuser just in front of Christmas from FLO. Now the 290MM mini (2.9um) was working on a SW ED50 guidescope and with the new multi star selection was getting very nice results.

I did however wish to try my 183mc (2.4um) on my 805mm APO and though an off axis guider would be required for this, I realise the match between the two is not good but wanted to try it anyway. Now I got the stars to focus and select in PHD-2 and made calibration without issue, though they did not appear as sharp as I normally get. The guide though was very up and down, I assume because the longer F/L of the scope, the SW ED 50 is only 242mm, so this is over 3 times longer.

Simple question is this to be expected, i,e, the guide appearing what would be about 4 times worse than normal. On the first test of the new PHD-2 it was a straight line much of the time, using the OAG it was anything but.

Results of 4 minute subs were not great but on a few stacked images the result looked reasonable from the point of view of using the 183MC with this scope, going to try the SW ED50 tonight to see what happens with that.

Alan

Lovely shot with nice detail around the flame and HH. I always find Alnitak annoying in any of these shots. One of our fellow Mods did a PS video on how to remove the glare from it but though I tried many times I could never follow it and use another method that Olly helped me with, one that I have long since forgotten.

Alan 

I had the L enhance version from them and didn't like the result, maybe I sold it on in haste and should have tried a blended shot or two. The result you have here I feel will benefit from that, though as I am sure you know you can always take shorter exposures of the very core and blend them. At the moment it would be nice to see anything, been awful here all month.

Alan

Lovely captures David, wish the weather would break here, been awful for a few weeks.

Alan

I am sure others know better than me but in my experience this is because you guide scope has moved or been moved and it need re-calibation. I have had the exact same thing about 6 times all told. Even when the scope was moved only a small distance fro where it was and I thought it wouldn't matter this happened, re calibrate the scope using your instructions which you can find in the help section.

Alan

1 hour ago, johninderby said:

Do nice warm socks count? 🤔.  😁

If it does my oh my there's going to be some cloud about.

Alan

Mine was in an observatory though subject to long periods of damp and extreme cold for 3 years, I really think covered up it will not be a problems.

Alan

Very nice shot with lot of detail, the trouble with this is it's so small, but a beautiful capture.

Alan

For what it's worth I am not exactly having a fun time many miles south. I got about 90mins two nights back but it was generally poor seeing and passing very light haze though i did get 15 subs of 4 mins taken. It was a chance to test the new multi star guiding, which I have to say seemed very good. Weather is not just mainly cloudy, it's cold and very damp.

Alan

2 hours ago, alacant said:

Sorry Alan

My bad. I didn't read your post properly. You had the l-enhance. This is the UHC. Both made in the same factory. It's the former I deemed overpriced.

Reading a little about them, they were designed for light polluted skies but IMHO they'd be better marketed sold as get-more-detail-in-nebula filters.

Be warned though, they need a helluva load more exposure time than unfiltered. 

I'm still not convinced; the stars look just as bad as with mono cameras and false colour. 

Cheers and clear skies.

Yes that was the one I had and was not impressed, yes they are pricey too, there is an extreme version now and that is about 230 quid.

When I had the Lenhance I just did the normal 4 minutes that I do, not very adventurous with time on the shutter, with my site I dare say I go double that exposure on a moonless night, must try some different lengths.

Alan

Done, nice image too.

Alan

13 hours ago, alacant said:

Maybe you had a different filter (?) as that one has the same graph. Maybe they're just re-marketed...

Cheers

I do remember it had a much tighter graph than you showed for the one you used, it is on FLO's sight if you wish to look. Gone now, the good thing is the guy that bought it was very pleased.

Alan

I prefer it with stars but interesting result

Alan

2 minutes ago, alacant said:

Hi everyone

A friend brought this along. It seems to do much like the new duo filters, but doesn't cost €silly (it says here).

I'm not a fan of/don't understand the latest false colour stuff, but this gives an interesting effect and seems to enhance the detail.

 

 

I can't find a graph of the false colour filter, but here's the spectrum for this one.

 

Thanks for looking and do post if you've had a go with one of these.

 

 

 

It is a very nice capture and has come out well. I bought a L enHance from Optolong and hated it, I actually sold it on before my card had been paid, just did not like the colours it gave at all. On reflection I should maybe have done a mixed stack to see if it improved.

Alan

39 minutes ago, JayStar said:

Thanks for the thought there... I did some measuring last night and found the the 150 will fit based on the measurements and some aggressive assumptions on the imaging train length. Funny you mentioned the plastic pipe, that is what I used (not 6 inches wide but cut to length).  It is a tight fit, though.

That said, after the note from Olly, I spent a lot of time looking at the FOVs on astronomytools for both the 150 and the 120.  The 120 probably offers, for me, more options at the FOVs I want.  There is such a price differential that I could afford the 120 plus a good smaller refractor, plus the flatteners/reducers, for wider FOVs (and still be under my budget). No decision made yet (as my mount is not even here until the new year)  but currently thinking Esprit 120 plus something like the GT71 WO triplet.  With flatteners / reducers for both that gives FL options of 336, 420, 647, 840.  With an ASI1600 that gives me FOVs ranging from 1.21x0.91 degrees to 3.01x2.28 degrees.  For me that seems to work really well and will use my 9.25 for planets (and some tighter shots of galaxies/nebula if I really want to - and am able to!)

Overall, given the above, I think the 120 is the better option for me - even if the 150 is still incredibly desirable!

 

 

Feel I would go for the 120mm, slightly shorter so a tad easier to guide, still very good quality optics and enough left from budget for a very nice camera or the bits you stated. I have 800mm, 635mm, 420mm and 330mm, as well as 1000m on a M/N 190mm that I have not used for AP yet, must try it, so pretty much the same as you. With me I spend so long getting polar alignment spot on I am reluctant to remove scope and swap around. 

Alan

17 hours ago, JayStar said:

The Esprit 120 might end up being the best option as it has to fit in the Obsy - that is something I still need to get clear on .. whether a 150 can slew unimpeded by walls, dome ceiling.  8*8 seems quite tight given the scope dimensions, but hard to estimate.

 

It is a shame you are not near me, I have a length of 6 inch plastic sewer pipe I could cut to length and put in the mount to have a realistic dummy run before buying.

Alan

A couple of my fellow Mods have SW Esprit 150's and they turn out some stunning images. I wish I had bought one when I could have out here for 3400, the dealer here is a friend, sadly he is not in business now. Olly has done some stunning captures with his TEC 140's too

I have also heard very good reports for the 120mm too, which if I am honest would be more my upgrade now for F/L reasons.

Alan

15 hours ago, Phillyo said:

As it's raining AGAIN here this evening, I had a little play with your data Alan. I think you just need a bit more integration time and if you can some Ha data to slot in and you'll have a fantastic image!

 

Sadly no H alpha available. If you wish to have a go at a longer Tif file I posted 14 hours of M33 about 10 days or so back, feel free to download that, so good result from people on that one. You have done well on this M31 though. Just checked the M33 data is 12 pages back.

Alan

11 minutes ago, astro mick said:

Hi Alan.

This hobby is full of woes and pitfalls,and things can take awhile to sort out.You will sort out the guiding.Your image is a good start for such a short intergration time especially for a OSC camera.

More subs will definately improve this.

Good luck with the OAG.

Mick.

Mick I feel it was just very poor condition. Prior to taking the gradient out the whole image looked very poor really which was clearly hazy thin cloud passing, even I am surprised it turned out as it has. Think I will try the OAG though as I also ordered a focuser to fit on it to make it easier. Must try not to drop things on the obsey floor. Recently I clocked up 20 hours on this at a longer focal length, I have always stuck to 3-4 minutes subs, just habit really but I still have a tendency to want to move on after 2 hours. I wanted to combine this year and last but I lost all the data in a drive crash. I didn't do longer this night because it was clear that cloud was amassing, it's been awful ever since, damp cold and cloudy.

Alan

A few months ago I dropped my SW ED guidescope which I have to say I rate for fit finish and quality. After it kissed the concrete floor there was an internal chip in the front element, not massive but big enough to cause concern. I later blacked it out altogether with paint but stars still had odd shapes, especially bright one. Guides seem decent though and sometimes even stunningly good.

So I change over the the guidescope for the new one I bought in front of 31st Dec and well enough in front Christmas. Did all the calibrations after a rough alignment and the guiding last night was absolutely awful, hope it wasn't the razor sharp stars I now have.

Didn't know what to shoot as cloud was moving in from the east, so 25 x 4mins on M33 with the Borg 77EDll and the 071 OSC, darks and flats and a 100% selection of captures. Going to try the OAG I bought back in February soon so maybe it was money wasted

Seems I missed the crop from the righthand edge but on the whole this gradient trick that Trevor on Backyard posted some time ago, seems to work reasonably well, just no good for very big targets and big nebulae, Olly spotted I had used it on M31 the other day, he don't miss much, but then that's why he's so good.

Alan