ollypenrice

Nice result with good control of the bright and the faint, which are a long way apart in this target.

Olly

Nice!

Olly

Last night I went outside again had exactly the same experience, with the same star. This has set me pondering about whether the effect might not be directly caused by the cloud, but by some process going on in the brain. I don't get the effect when I go out into a clear sky but perhaps something needs to settle in the brain when it observes a single star isolated by cloud. Something to do with orientation? I will try to find out whether I still get the effect if I'm dark adapted before looking up.

Olly

A few nights ago I went outside to find a semi-cloudy sky and noticed a bright light in a hazy patch, west of south. I saw it very clearly move directly downwards at a jerky, variable speed so I wondered what it was. As the sky cleared it stopped moving and turned into a perfectly normal, stationary star - which is what it was all along, of course.

I don't recall seeing this illusion before but it told me a lot about why people think they see moving objects. I suppose the clouds create the illusion but can't be sure. It was very striking and I'd have sworn I saw a downward trajectory.

Olly

3 hours ago, michael8554 said:

A Spotting Scope for Bird Watching.

On a tripod.

Gives an erect image.

Can you open the window on the 30th floor, as glass will blur the view ?

Michael

This could be a small desk-top tripod if there's a suitably placed desk. I don't suppose windows on 30th floors open up all that widely? 👹

Olly

I love the first one, especially in its rendition of the dust (and I agree with  tooth_dr about the refreshingly different framing. In the second one I feel the colour has gone out of kilter, especially the Flame which has lost its unusual orange-yellow.

Olly

15 minutes ago, DSOBug said:

Ive seen several people using Dark Filters to take Dark's with instead of using the scope cover any comments on this? it seems it would be easier to just run a process to rotate filter wheel and take dark's with a dark filter during your routine.

Seems very odd to me. Are you sure? You really do need to exclude all light when taking darks.  I compared darks done on the scope with the lens cap on with darks done with the camera off the scope and its metal scew-fit cover in place. The ones done off the scope were different and had slightly lower ADU values. I can imagine an opaque filter plus a lens cap being useful but some scopes, notably Newts, often leak light from beneath the mirror. Off axis guiders can also let light in.

Olly

I don't think the stars are over-controlled except in terms of their colour. Of course, most star colour is found around the fainter edges so, when these are reduced, so is the colour. If you could get a bit more colour into them I think you'd be spot on. It's a tricky target to process and I think this is very decent indeed.

Olly

Long integration always shows its class.

Olly

On 18/11/2023 at 19:42, Ricochet said:

I think the general consensus is that while they are very dark face on they tend to be more reflective at shallower angles and so breaking up a flat surface by giving it a texture will give the best result. There is a thread in the diy section about mixing sand or sawdust into the paint to achieve this. 
 

I used Musou black and flocking on my 72ED in three ways; flocking inside the dewshield, flocking that was then painted inside the OTA, and paint straight onto the inside of the drawtube. The painted flocking gave the best result and the straight paint the worst. The finish when painting it onto a larger smooth surface wasn’t very good either, but on small areas it worked fine. I can still see reflections from very bright objects from areas coated only in the paint, although I think it is still better than the factory paint. 

I don't like the idea of sand escaping near optical surfaces so I'd go for sawdust myself.

Olly

16 hours ago, AKB said:

No!!  Temporary, or permanent?  I still love my M-Uno, and had been using it whilst my Mesu was in disrepair (servo controller, not mechanics.)

Tony

Don't know yet, Tony. I'm trying to find a manual for dismantling it. It won't be much - just a broken wire or something. It's not the motherboard for which I have a spare.

Olly

18 minutes ago, Elp said:

The current option I'd look at is an Edge HD 8, with a Hyperstar you can do F2 widefield imaging, and still use it for planets at its native focal length, and use it for visual. More cost though for additional items. Currently I use a C6 like this, the edge HDs are better designed.

Each to their own, but I wouldn't touch a Hyperstar with a ten foot pole. If you read enough owner accounts, and look at their results, a pattern emerges: a few people get decent results, most don't. I agree absolutely with your earlier point, though, that a RASA should be bought only from a very reputable dealer with good returns policy.

49 minutes ago, Victorw said:

 

Another naive question: I know Rasa is for deep sky, but can it still produce good images for jupiter-like planets? Maybe not enough focus lengh? 

Nothing like enough FL. The RASA is a widefield instrument, pure and simple.

Olly

I love the RASA 8 but it isn't perfect. I'd still refuse to swap it for anything else.

Firstly you need to match a camera to it.  A DSLR is too big to fit in front of the corrector without obscuring it. We use a ZWO ASI 2600MC Pro, which has a fairly large chip. We don't get perfect stars to the edge but can 'fix' them in post processing. A smaller chip would reduce this problem at a cost in terms of field of view.

Our image scale is about 1.8 arcseconds per pixel, which is not very demanding in terms of mount/autoguiding tracking accuracy. You need an RMS of about half that, so 0.9" RMS. When our more upmarket Avalon Linear packed up recently I chucked a very old EQ6 under it and and, quite honestly, there is no loss of quality.

You might also want to check out the issue of tilt...

Olly

I do know that there are paints made with pigments and cheaper paints made with dyes. Those made with dyes are not absorbent of all wavelengths, so are reflective just outside the visible spectrum. Heat proof paints for stoves, barbecues, etc., use pigments and are not reflective in this way. This came up as a topic a few years ago regarding the shooting of flat field frames in astrophotography. How relevant this will be in visual observing, I don't know but the blacker (the less reflective) the better has to be true.

My wife is a professional painter and, of course, uses top quality pigment-based paints. The density and intensity of their colour is mesmerizing. I found this fascinating and did a series of macro photos of her palette in use. Make no mistake, there is paint and there is paint.

Olly

1 hour ago, vlaiv said:

 then I realized it sounds way too much like a very nasty medical exam

All orifices invaded at the same moment!

lly

1 hour ago, Bugdozer said:

Why is that? Is it because they tend to get more problems, being a complex design? 

I suspect that it's because they were massively advertised at one time, and over-sold to boot.  The manufacturers pushed them for deep sky imaging when, in reality, they were pretty poor for this and people wanting to go into imaging sold them and went for alternatives. The arrival of the tiny-pixel DS camera has made their long focal lengths even less attractive.

I don't think they give much trouble. I've had four and all have been perfectly reliable. The spherical primary is easy to manufacture and collimation is simple. The long FL is restrictive but they are pretty nice as long as this is accepted. In a nutshell I just think they are too numerous and not suited to DS imaging.

Olly

Can't we just dump this thread and get straight to the heart of the matter - polygamy!!!

lly

SCTs have a low resale value at the best of times, compared with most other types of scope. Although this probably won't affect the view, it will massively affect the resale value. I don't know what a used C5 goes for these days but, whatever it is, I would not pay more than a third of that price for this one.

Olly

As usual, capture and pre-processing by Paul Kummer with my post processing.  RASA 8/EQ6/ZWO2600MC Pro, based here at Les Granges. 131 subs of 3 mins, so about 6.5 hours.   The Fireworks galaxy has been gently enhanced by the blending of my existing TEC 140 rendition.

Processing: a little Pixinsight, Registar for the high res blending and mostly Photoshop.

Fullsize is here: https://ollypenrice.smugmug.com/Other/Galaxies/i-CcqZKsR/A

Olly

If you were to ask me about the cosmetic condition of any of my telescopes, I'm happy to say that I can give an absolutely precise answer in every case, without leaving my desk. The answer is, 'Dunno., I don't look at them, I look through them.'

As for this,

22 hours ago, John said:

It didn't stop William Optics having a go 😲

...vomitworthy. How embarrasing is that?

Olly

15 hours ago, whipdry said:

Tak green is a bit NTSC, some owners might not agree... the paint pictured worked ok, sometimes needed a tad of black added depending on what Tak green you have?

Btw this pot of matt actually dries with a sheen almost gloss...

Peter

I doubt you'll beat that.

Mods, might this get a sticky since it would be so helpful to Tak owners?

Olly

You could ask for an American member of SGL to buy the paint for you, perhaps, and send it on.

Olly

The bloat is also quite magenta, so green is low - for whatever reason.

Olly

I've had 8, 10 and 14 inch SCTs and still have the latter two. They do need dewsheilds but they need them a lot more than a refractor needs them! Whatever you use to combat dew, on a dewy night an SCT will get shut down before a refractor. Long before - and I live in the south of France, not Norway. Camping mat makes brilliant dewsheild material, by the way.

Olly

I started to have a play with these data but ran into a problem with ABE creating contour lines. I don't have the time to try to sort this out because a robotic shed issue is all-consuming at the moment.

However, I saw no reason for the background to become blotchy and I really saw no vast amount of noise to deal with. Is this because I may be stretching differently?  I've seen lots of stretching videos where the imager keeps on stretching and then pulling in the black point, over and over. This seems crazy to me. Once the darkest part of your image has reached the brightness value that you want it to have, why stretch it any further? Why not pin it in Curves and stretch only above that? Why pull your dark signal up above the noise floor? In the case of this image, there is dark, sooty nebulosity well below the brightness of the more transparent background sky so, once this sooty stuff was up around a Value of 17 in Photoshop, I pinned it and stretched only above it. It all looked pretty good to me.

I don't go for any of the bought-in, sliced cheese stretches with began with DDP, years ago. I'll use a standard log stretch till the darkest signal is where it needs to be then I'll only stretch above that.

Olly