ollypenrice

32 minutes ago, symmetal said:

Thanks Olly @ollypenrice,

On my Horsehead I posted recentlyI did use PS layers to change the hue/brightness of the two small blue flares to match the background which worked very well. Looking at the RASA 11 FOV I'm surprised that the flares weren't a lot worse. I assumed they came from Alnilam, outside the camera FOV but well within the RASA FOV so the effects were minor. It seems Mintaka was just far enough away not to cause the hard edge full width flares, along with the rainbows, as the postings above show.

I can use PS layers to reduce the brightness/colour on the triangular flares and 'paint' out the rainbows either with a different image or content aware fill as necessary.

My attempt at reducing the aperture from 279mm to 250mm to reduce the flaring only reduced the f-ratio from 2.2 to 2.48 so maybe it wasn't enough to really affect the result. A more restrictive aperture mask, f2.8, f3.3 or f4 even,and subsequent longer exposures may be an easier solution on problem targets if it works. Do you think it's worth a try or is my reasoning wrong? 🙂

The trials and tribulations of fast scopes I suppose. 

Alan

I remember having shaft-like out-of-shot flares affecting Tak FSQ images (F5) and ODK14 images (F6.8). I wouldn't be too sure that it had anything much to do with F ratio but I really don't know. With the RASA we do get arcs, on occasion, rather than 'shafts.' I just go for a cosmetic fix on the starless layer. So far so good... I don't regard stopping down as an option on either of our F2 systems. F2 is just too good to mess with! 

Olly

40 minutes ago, Skipper Billy said:

I havent tried them but catching up in the various forums it seems that almost every man and his dog are using BlurX, NoiseX and StarX etc. I might investigate!

My big thing is processing: Star X and Noise X have changed the game. Blur X is good provided your star shapes are decent to begin with. It's the least important of the three  but stretching an object without stretching the stars is bliss. Star X. You won't look back!

Olly

That's very nice with lots of texture in the nebula. There's a distracting amount of green in the background along the lower quarter of the image and on the right hand side. This would be a very easy thing to avoid using Hasta La Vista Green or SCNR green in PI. Also an easy fix even on the finished image as we see it. That apart, that's a hell of a lot of image for 33 minutes!! I'm impressed.

Olly

50 minutes ago, Stuart1971 said:

Hmmm, I have had a few Atik CCD in my time and never seen that, I think @ollypenrice used to use an Atik 16200 too, just never noticed the spikes before, especially with a frac…but then maybe you re correct…👍🏻

No, I'm afraid I never had this one. I had 7 Atiks but never this chip or the 8300.

These artifacts don't bother me but if they do bother an imager they are a simple cosmetic fix in Ps.

Olly

5 hours ago, Neutrinosoup said:

No stairs:

1) site 1 = front garden on concrete slab (20-30m from storage)

2) site 2 = field behind house on levelled concrete platform  ( 200m  + small incline to get there)

The classic wheelbarrow handles might work for you, then.  https://www.google.com/search?q=dobsobnian+wheelbarrow+handles&rlz=1C1CHBF_enFR821FR821&oq=dobsobnian+wheelbarrow+handles&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIJCAEQIRgKGKAB0gEKMTE5MTFqMGoxNagCALACAA&sourceid=chrome&ie=UTF-8#vhid=aue2pqn7Umgm0M&vssid=l&ip=1

Olly

50 minutes ago, Skipper Billy said:

I have looked at it again in the cold light of day and you are absolutely right - it looks ridiculous!

I have processed it again from scratch and left the stars alone. I am very rusty at processing after an 18 month absence but I am happier with this version than the first one. I might have another go as I think I have overcooked the star reduction and sharpness.

 

IC410 TADPOLE NEBULA.tif 35.35 MB · 0 downloads

I think that's much nicer.

Have you tried Russ Croman's Noise Xterminator? It is utterly astounding and miles ahead of any other NR routine I've tried. It probably came along while you were out of action and I think it would be ideal for this image.

Olly

40 minutes ago, Ouroboros said:

40 minutes ago, Ouroboros said:

The reason is obvious of course. Curves works on intensity. The Curves process  is completely unselective of whether it attenuates the faint outer edge of bright stars or the fainter stars themselves.

Yes, that's true. I do, quite often, selectively process a handful of bright stars which haven't responded well to the overall stretch. This is easy with the selection tools available in Ps but I don't know if PI has an equivalent.

Olly

It seems that you can generate a star image, which I take to mean 'stars only.' That's what it gives me in Ps and that image can be manipulated in Curves before being finally applied over the background. Pulling down the bottom of the Curve more than the top will bring the fainter stars below the brightness of the background, so they become invisible.

Olly

2 hours ago, Ronclarke said:

Thanks for that Olly, seems a long time since I visited you!!

Indeed so!

Olly

I've had flares from out-of-shot stars with various scopes. I can suggest two solutions, one more 'ethical' than the other.

1) You can make a patch panel by shooting a fairly short run of subs with the source star closer to the image centre but with enough overlap to cover the flare. You just use this patch to replace the flared bit on the original in Photoshop Layers or whatever.

2) If you use a star removal product, once you have a starless image it is dead easy to lasso the flare and use Content Aware Fill in Photoshop - provided there is nothing much going on under the flare. If it goes right through the middle of the Horsehead, this ain't gonna work! 

Olly

You need to tell us the kind of portability you need. Stairs? Transport by car? Just rolling it out from garage or shed? For the latter, a 20 inch is no problem once you're organized.

38 minutes ago, Astronomist said:

You could look at orion optics UK, their products look very good, however their reputation is less than stellar.

'Less than stellar' is the understatement of the year in my house. Anything more must be by PM.

Olly

OK, I'm not so sure about the rationale behind using two palettes in the same image. I can certainly see the point if, like HOO, the palette closely resembles RGB but the Hubble is in flat contradiction with RGB. I'd be more inclined to combine RGB stars with HOO. I think this would look more consistent.

Olly

Good! The stars across the field are really classy in the M45 shot.

Olly

It largely depends on the target, surely?  Some don't have much fine detail, some have lots. I'd call the California relatively low on small scale detail at shorter focal lengths.

Since I remove and replace stars anyway, and give them an entirely different stretch from the subject, I find myself using the standard stars over the BlurX ones but I like BlurX on fine target detail.

Olly

Do you use StarXterminator?  It's a wonderful tool for controlling star size, and manipulating the Curve on the star-only layer does give control over fainter and brighter stars independently. I don't do this in PI but in Ps, but it ought t be the same.

Olly

1 hour ago, michael8554 said:

The 150PDS and 183c Pro give 0.66arcsecs/pixel, perhaps a tad over sampled ?

So Binning to 1.32arcsec/pixel might be better for UK Seeing conditions.

Michael

More than a tad, I think. Massively oversampled anywhere with those optics. I found 0.66"PP oversampled using a 14" ODK at a guide RMS of 0.3 arcsecs.

What is your guide RMS in arcsecs, Ron?  A good EQ6 runs about 0.5" and that will support an image scale of about 1"PP, so nowhere near 0.66"PP.

Darks do need to be the same as lights but flats could be resampled upwards to their unbinned equivalent. I'd shoot new ones, though. Except that I'd stick with the binning...

Olly

Another Olly (but with a 'y') here.  Greetings.

I've been using a RASA 8 for two years, now. It really is a scope from which there is no going back. No F2 system is going to be dead easy but the RASA is very remarkable in some key respects, most notably focus. Incredibly, it autofocuses easily and holds focus better, if anything, than the premium refractors I've used. Tilt is going to be an issue at F2 as well, but it is just as likely to come from the camera as from the scope. Patience in the early stages is all. A good dealer like FLO will give you chapter and verse on the bad batch of optics Celestron received from China.

I haven't used a Hyperstar but have read many tales of woe regarding setup and I'm very rarely impressed by the stars in posted images, especially broadband. RASA stars are pretty good, especially using star removal and replacement in post processing. (I think almost anyone working at short focal lengths is going to want to use this method these days.)  Personally I would not buy a Hyperstar but that's me. I also find their marketing blurbs borderline illegal and in contravention of advertising standards, which does annoy me.

Sample RASA 8 images:

https://www.astrobin.com/eolyxc/

https://www.astrobin.com/rwyqce/

https://www.astrobin.com/bubqfe/

https://www.astrobin.com/vlomu9/

Olly

Great choice of gear. Compact and potent. The new CMOS cooled cameras roundly beat CCDs, let alone the older DSLRs. At some point you might consider a dual or tri-band filter designed to work with one shot colour. I use the same camera plus another with the same chip and I recently had a couple of Redcats visit. They gave pinpoint stars across the chip. Very impressive.

Olly

First a gentleman. And then a very fine telescope craftsman. I went to his home in Nottingham to discuss a possible order when I was setting up Les Granges twenty years ago. Sadly I had so many demands on my available funds at that time that I had to go for a lesser instrument, second hand. However, I still have a vivid recollection of his courtesy and gentle manner. He really did make an impression on me and I'm deeply saddened by this news. Condolences, of course, to his family.

Olly

1 hour ago, Kinch said:

Lower's nebula.....and I don't think it is ignored by NB imagers....I have done it a couple of times. You are correct about the OIII.

It is actually not such an easy target to image - this was my last effort  in '21

https://www.kinchastro.com/sh2-261.html

Very nice work indeed. The thing about a NB palette is that it allows far more distinction between OIII and Ha emission than is possible in natural colour.  Paul did say it was known as Lower's nebula but I clean forgot.

Can we tempt you to add a second panel in search of that southern loop? (Our version is N up.)

Olly

2 hours ago, tomato said:

Does it even have a popular name? How about the Angelfish Nebula, I see one swimming left to right.

As far as I know it has no popular name and yours fits. It seems to share some structural similarities with the Rosette in that the circular, central part may have been excavated by radiation pressure from stars formed within it. Judging from the fact that the centre is bluer, as with the Rosette, that may be where the OIII lies. Does the OIII form later or are its heavier atoms just less prone to being swept away by the radiation?

Olly

1 minute ago, Budgie1 said:

Not one I've come across, Olly, but looking at Stellarium, it's one that's visible to me for about 6 hours per night at this time of year with no trees or hills to get in the way.  So, hopefully, get some SHO data next week.

Thanks for posting.

Clear skies!

Olly

Imaged with Paul Kummer who did capture and pre-processing.

We became interested in this when we found a large, bright nebula halfway between Betelgeuse and the Jellyfish Nebula on our Orion-Monoceros mega-mosaic. What was it? Why didn't we know about it?  This was no faint little obscurity, it was right there and shining. Sh2-261. A nice one for the narrowband specialists. My guess s that the OIII will be significant.

RASA 8/NEQ6/ASI2600 OSC.  118x3 minute subs.

Here's our mosaic with these data blended in.  https://ollypenrice.smugmug.com/Other/Emission-Nebulae/i-24FpLf3/A

Olly

One more for Baader film and remember to cover you finder!

Olly

3 minutes ago, saac said:

From the moment the camera was invented it was mated to a telescope. Photographing the cosmos and the stuff in it is as part of astronomy as nighttime is.   There is no divide, there is no one or other.

Jim 

The last great eyepiece professional and the first great astrophotography professional were one and the same person, the incomparable E.E.Barnard.

Olly