alan potts

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

18 hours ago, DaveS said:

Had a quick play.

Pulled the TIFF into AA7 and decomposed into separate RGB channels

Applied Gradient Reduction > Adaptive Subtract to each

The individual files into Trichromy followed by a slight colour rebalance.

DDP followd by a slight Saturation Boos while holding back the background then export as TIFF

Into Affinity Photo for Channel Mixer > CMYK and reduce the magenta in the magenta channel.

Finally export as Best Quality JPEG

Had a quick play, sounds like you spent ages on it reading that, most of which I am sad to say i don't understand. A very nice result though and the pick of those done in my opinion. Thanks for posting.

Alan

28 minutes ago, John said:

It's worth a look anytime now if you get a clear sky. The chances of a clear sky at the time they are actually closest has to be slim given the conditions recently.

While I'm looking forward to seeing them close together, I've been in this hobby long enough not to pin too much on such events

 

Made mistake of buying gear in front of 31st, you know the rest, maybe by 21st I will be forgiven.

Alan

27 minutes ago, alacant said:

Hi

I tried light pollution filters and TBH, I came to the conclusion that if you want to get natural galaxy and star colour (and there aren't many of us left!) you're better without. Otherwise you're fighting colour which has had chunks of the visible spectrum removed and impossible to replace.

If you can't get StarTools working for the gradient, Siril which is a free download, comes a close second. Or just go with whatever you're most familiar.

Cheers

 

 

I have looked at both these and I am not very IT minded though I know my way around PS, I found the crop for example in Startools ridiculous, I will have a play with it another time after all PS is able to pretty much anything if you press the right buttons and it wasn't cheap. Thanks for pointing me in that direction, it will just take me time. I think this IDAS filter is a slightly better option for LED light, if I don't like it well, on the shelf I guess.

Alan

2 minutes ago, ollypenrice said:

Given the cost of the gear, a potent gradient removal tool punches well above its price weight but you mention not wanting to pay for things online. I wonder if any of the options would be available by cheque.

Olly

I must have a look into gradient removal Olly, I know it can lift any shot to the next level, I know a few way to do grads but these is always a target that fools them. I tried to take your advice given a good while back now on spend 3 nights on a target, not 3 targets in one night. I rarely stay more than 3-4 hours outside but have now managed 20 hours on M33, which is quite something for me. I was going to add to data from last year which I had all foldered together but the drive crashed and I lost the lot.

Now after buying a few things before brexit throws a spanner in the works, weather is set poor for a week. Hope to improve my guiding too with a OAG, at least on the 800mm APO.

Alan

58 minutes ago, ollypenrice said:

That's very good, Alan. Flat background and tight stars. (Always the hardest parts!) You could bring in the black point a tad, too, maybe.

My own feeling on playing with the data was that the scope had done a decent job. Stars were consistent across the frame which is the main thing. With the present post-processing tricks now available, having inherently tiny stars is no longer such an imperative. There are two things I'd want to understand better:

1) Colour. What's the camera? Unfortunately I have zero experience with LP filters so can't be of any help but maybe those used to using them could chip in.

2) The data seems to me to cut off rather dramatically around the outer part of the galaxy. There is faint galaxy to be had beyond what we are seeing here but I couldn't find it in the data. Maybe it just isn't getting through the filter, in which case more subs/longer subs might find it. (In the end I prefer your stretch to mine because you haven't chased that outer signal and I've chased it too hard.)

Olly

You don't miss anything do you. First this was taken with my 071 which is of course a OSC. I am only trying this filter from IDAS as it is meant to filter out LED and in the south east I have an LED glow from the town, but nowhere else, it's just easier for me to image that way as my walnut trees reduce south west time on objects. The reason why there is the cutoff that you picked out is that I don't have any graduation software so I use the healing tool technique in PS to graduate the background, which I thought I had got away with, but not from you. So it may well be there but I could have covered it. It is a good technique but maybe this galaxy is a bit too big to use it, works a treat on smaller ones. I can easily go to 5 minute subs here and probably longer 

It could also be a tad darker so I agree with you, I tend to hurry processing and that is not a good thing,

Many thanks Alan

12 hours ago, ollypenrice said:

Colour was tricky, with rather overbearing greens in the galaxy and very red stars. There isn't a lot of colour differentiation to work with either, but that's usually a matter of integration time. I felt it was beginning to go in the right direction by the end so more data would help.

PI dealt with the background sky nicely (DBE, not too many markers) and SCNR green helped with the colour. Stars removed in Starnet++ and then replaced in Photoshop with a soft stretch used in blend mode lighten.

Olly

Thanks Olly, a nice rendition as one would expect from you. You talk of integration time, any pointers of which way to go on this. The Borg is F4.3, a devil to focus and not giving the results I would expect for a scope costing close to 2000 usd, not that I paid that. It also is not ideally matched with the 071 but I do that purely for the wide field. No matter what I do you do seem to get these orange stars coming through in the images more than I would like. I have tried the two different IR/UV filter, L2 & 3 and now have a IDAS D2 filter to see if that helps with all my scopes. I have a bit of LED glow to the SE sky from the town, they call it progress. As luck would have it all other directions are free of any LP for many miles

I had another play about and turned it up what I feel is the right way and it does I think look a bit better

Thanks for you efforts  Alan

8 minutes ago, alacant said:

It's compressed. Save it as a pure tiff ( or better .fits) after you have stacked your frames. I converted it.

HTH

It was just out of DSS, How can you convert them, I will try a FITS DSS stack a bit later. This free software, do you know how long it lasts?

Alan

7 minutes ago, alacant said:

Oh dear.

Are you perhaps trying to open a compressed/non linear file, such as the OP's?

Cheers

 

I have no idea, the same file you had a play with and produced this rather nice image.

Alan

3 hours ago, alacant said:

Hi

I like it. Some lovely detail.

Can't get a single Tiff file to open in this program.

Alan

I am amazed how many really different colour castes there are going on in one set of data and how different tools change things, PS is easy to add or remover different colours, maybe more so than any other program. I really like the version Alacant has done with the small tight stars but ideally, and only personal taste, would like a bit more colour in the galaxy. Great to see what you all do though.

As per normal, I have just received a delivery from FLO, checked the forecast and it give 8 days of rain cloud, snow and more rain.

Alan

1 hour ago, alacant said:

Hi

I like it. Some lovely detail.

How did you process it, you appear to have much smaller stars than I managed?

Alan

Just now, alan potts said:

I will dig it out. I have used the super pixel mode in DSS to reduce the file size but it is still useable

Autosave007.tif 14.16 MB · 0 downloads

Alan

 

If anyone else wishes to have a play feel free to download it.

Alan

Just now, michael.h.f.wilkinson said:

Definitely beter. If you could share the unstretched FITS or TIFF I could have a bash in APP, if you like, just to see what it does

I will dig it out. I have used the super pixel mode in DSS to reduce the file size but it is still useable

Autosave007.tif

Alan

Toned the yellow down a shade or two.

Alan

3 minutes ago, michael.h.f.wilkinson said:

Nice detail in that shot. The stars and core do seem to have a bit of a yellow cast. I find that gradient removal and star/background calibration in APP work pretty well. Maybe worth a shot

 

I keep looking at APP but I do not like using cards on line. I did lift the yellow a bit may well have over egged the pudding Michael, feel guiding could have been better, which has been very up and down of late, night before last it was stunningly calm below .2 of a pixel.

Alan

I am still fighting this Borg 77ED ll which though it looks cute and pretty I am not in love with. Since last years poor efforts I have spent more time focusing and had bought a Astronomik L3  IR/UV filter for it, something quite a few suggested. Still can't say I like the results I get though. I have recently tried the PS gradients technique as outlined by Trevor Jones on Backyard. Though I didn't really spend a lot of time on the process the gradient removal for most subjects seems to work well. I have also got a LED LP filter on the way to hopefully remove some of the sky glow from the town. When I started 14 years ago you couldn't really see any light from the town at all but in recent years with low quality badly shielded LED's it does cause a small problem in the most import area of the sky SE, rising area and now where Orion is sitting. This I normally wait for it to move west of south, where it is black.

Anyway, here is 2 hours of 3 minute subs with calibration frames taken at minus 5C with a 071. Not very cold I hear you say but I have studied a number of my images at different temperature and can't see any real difference.

19 hours ago, vlaiv said:

It is just method of debayering.

Instead of interpolation, it just uses bayer matrix of 2x2 pixels of different color (RGGB for example) to produce single pixel with all three colors - R, G and B.

It is available in DSS and I'm sure it is also available in other software. With DSS, you just need to select it:

As you see - resulting image size is divided by two, so you'll end up with images that are 1504px x 1504px in size. Hence, resolution will be two times smaller as well - instead of 0.78"/px it will be 1.56"/px. In reality, because of Bayer matrix, you are sampling at twice lower rate than pixel size suggests, so this is convenient way to get actual sampling rate of color camera - which suits you better.

Must give that a try on the 183mc, never seen or heard of it before.

Alan

2 hours ago, Moonshed said:

Hi Alan, it must have been quiet a spectacle, I haven’t seen any but would love to, as long as they didn’t mess up any subs lol.

Keith

I have that plane tracker on the computer and opened it last night whilst in the observatory to see there was just the one plane in the airspace around here for many miles, you guessed it flew right through the middle of my first sub. Lord knows what the string of lines would have done, very interesting sight though.

Alan

16 hours ago, Moonshed said:

It’s events such as this that get the UFO brigade going into overdrive, and not forgetting of course those poor abductees and the horrors they went through. Yeah, must have been awful, apart from the tour round the galaxy bit lol.

I have to admit I wondered for a split second, then though i didn't know what they were remember a comment a while back saying about these going through someones astro photo frame, I got my wife and son out to see them.

Alan

1 hour ago, theropod said:

I’g only seen one string of 21 such eyesores,  but with time it will become the norm instead of the exception, sadly. My string were all spaced very evenly apart.

In the main they were spaced pretty much even but a few were out on order, I would say it was a string of 30 or so.

Alan