-
Posts
38,260 -
Joined
-
Last visited
-
Days Won
307
Content Type
Profiles
Forums
Gallery
Events
Blogs
Everything posted by ollypenrice
-
I counsel peace! For me, the X suite AI tools are excellent but not perfect. Some vigilance is called for to check that they don't make spurious additions or deletions. That means checking them carefully against the unmodified image at the same stretch. I now do this. Rejecting them altogether would be like throwing the baby out with the bathwater, for me. When I add Ha to red in Photoshop (and since Ha is red, that's where I put it) I do so by making it a layer on top of red and choosing blend mode lighten. This means the Ha is only applied where it is brighter than the red. However, at this stage I still have fine control of the mathematics involved in the blend. I can bring in the black point of the Ha and I can shape the curve in Curves. Simply by shaping the curve I'm creating new formulae adapted to the image in question. The mathematics of the formulae are invisible to me but the consequences of the formula are visible in real time in front of my eyes. Why would I do it any other way? In Powerlord's image I would be able to look at those magnificent Ha jets (of which I'm very jealous! 😄) and shape the curve so that only the thin jet filaments made it above the red floor. The Spanish Inquisition will accuse me of heresy or 'painting,' to which I can only say that PI users will do exactly what I do in the end and that is choose the final result based on subjective preference. Cheating? Where are the rules? We make our own. My rule is to try to make beautiful and informative pictures. Olly
-
Overall I think it's very good. The only bit that jars is the brown region which surrounds the Ha jets. I think that is spurious but, for the rest, you have good agreement with Hubble. The main outer glow may also be a bit blue but, hey, the image has something to say. I have to say that all these complicated ways of adding Ha leave me a bit mystified because, in Photoshop, it is so easy to control where the Ha is and is not in play. Call that the last gasp of a dinosaur. lly
-
On your budget I would consider a RASA 8. The focal length is only 400mm but the large aperture gives good resolution of detail and the speed, at F2, is simply phenomenal. When I started using this scope I saw it as a widefield nebula (dusty and emission) tool but, if fact, it is doing remarkably well on small targets requiring good resolution. There is a catch: it can't be used with a filterwheel so you can use it with straight one shot colour or as one shot colour via a dual or triband filter for narrowband. Also I'm not sure about the HEQ5 with the RASA. The speed of the system, though, means you can happily work in short exposures. I've never had an HEQ5. Others may come in on this. A word on your requirements. You say, '...such as Veil, Heart Orion nebula, M31, M33 and such like? ' I don't really see how these can be grouped together. The Veil is nine times larger by area than M33. For M31 we needed a 2 panel mosaic at 400mm with an APSc chip. At a metre, with a full frame CCD, I also needed a 2-panel. Olly
-
Bravo! The most reassuring thing, when chasing faint tidal tails, is to find good agreement with other imagers working independently. I think our results are, indeed, in decent agreement. Nice agreement also on PGC30397. I particularly like your bold red stars as well. Olly
-
How safe do you feel?
ollypenrice replied to Samop's topic in Getting Started General Help and Advice
I think one problem, certainly in the UK, is that sites which attract the car-bound astronomer will also attract car-bound people of questionable intent. Somewhere to park and nobody around make common ground between the two. When I go back to Derbyshire I see that, on most country roads, a pull-in where a car can stop will have a few lager cans lying on the ground. Depressing but true. People who drive out to drink lager and who throw their tins on the ground, are not people I want to meet in the dead of night (or anywhere else for that matter.) Olly -
Astro Magazines - Europe
ollypenrice replied to Mattiman's topic in Getting Started General Help and Advice
Are you looking for English language publications? Olly -
I'm often one of only a few people on threads like this who says, 'Don't bother with the DSLR.' Beginning with a DSLR is not compulsory and, since CMOS is now the top technology, astro-specific CCD cameras have become remarkably cheap on the used market. You would have no trouble finding one for 500 euros and they are so much better than DSLRs, they really are. Also, you're in Greece, where it is hot. An uncooled camera really is going to struggle where you are. Olly
- 49 replies
-
- 4
-
Is it the LP which makes you reluctant to use luminance? Olly
-
Travel setup ... with checked airline bag?
ollypenrice replied to Basementboy's topic in Discussions - Scopes / Whole setups
I'd go for the 4 inch refractor, perhaps packed in its rigid foam hard case lining within a larger bag. I've done this before. Indeed, I once flew with a 5 inch F7 without issue. You can be unlucky with baggage, of course, but I've flown sixty times with a bicycle in the hold and never had any serious damage. It isn't that bad! Olly -
I just split the channels on my own M101, which has strong outer extensions, and blue is the brightest, though they are present in all channels. Olly
-
Out of adversity... the Blue Horsehead Nebula, IC4592
ollypenrice replied to Fegato's topic in Imaging - Deep Sky
Oh, that's an absolute winner, beautifully done. We don't see many images of this quality, let alone from low elevation and with short integration. Loud applause from me. Olly -
The south of France has some great skies! lly
-
Setting aside the faint extensions, that is a contrasty and sharp image. Since the faint extensions aren't red (or Ha) you can't expect to find them in this palette, surely? There's no fine detail in the faint extensions, at least accessible to amateur telescopes, so I'd just throw everything you have at them and blend them with this. Olly
-
It's nice. There is very little blue information here, though. Might you be able to tease out a little more? Olly
-
M13 Great Globular Cluster in Hercules
ollypenrice replied to mightymonoped's topic in Imaging - Deep Sky
There's a lot to like about this. Right towards the middle of the cluster, though, I think you're saturated. That means that everything is at the maximum value of the screen. I think it's unlikely that this will be true of the individual subs - though looking at them in linear form will tell you. If there is a range of brightness visible in the core of a linear sub, that range of brightness can be preserved in the stretch. It just requires super careful control of the stretch, possibly using Curves rather than a generic Levels stretch. Olly -
Combining Data from Multiple Sessions Question
ollypenrice replied to Sarek's topic in Getting Started With Imaging
I don't use Pixinsight for this task but you clearly need to use the right calibration files for each sub. You can't use last year's darks on this years lights, so to speak. From what I've glimpsed on here, I think PI makes this a simple enough task - by PI standards. Olly -
Very good! The Squid is a faint so-and-so yet there it is. Olly
- 1 reply
-
- 1
-
Space X's favourable spin on this explosion reminds me of how politicians who have lost elections rabbit on at length about the many positives of the result and how, properly looked at, it represents a great step forward for their party. Olly
-
Jones Emberson 1 - Headphones Nebula.
ollypenrice replied to ollypenrice's topic in Imaging - Deep Sky
There's no flux visible in the screen stretched linear stack, Earl. None in the 6 hour version below, either. Paul doubled our data set, with the new subs also being dithered. This has 6 hours, now. As with all things AP, the difference is probably borderline imperceptible to the casual viewer yet a cause for great rejoicing among the imagers themselves! The detail held up so well, in this version, that I felt it could hardly be seen at full size so, for the first time ever, I upsampled it by about 20% and that is what you see here. Olly -
The Dusty Pleaides - Esprit100 GT71 Askar200
ollypenrice replied to Laurin Dave's topic in Imaging - Deep Sky
A truly great image. Flawless. You are right to be pleased. Olly -
There was nothing wrong with the details, they were great. A good test of image colour is to check the spectral class of the stars in a catalogue. If the OB class stars in an image aren't blue - they should be! Olly
-
The whole image is very red. Indeed it looks fairly monochromatic brown. This is a surprise because the 2600 OSC chips I use tend to be colour cold. Are you using some kind of LP filter? It might be productive to look into what's subduing your blue and green channels. Olly