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Everything posted by ollypenrice

  1. ollypenrice

    Bode's Galaxy - 21hrs LRGB

    Really cracking image but Martin has a point, particularly since the image is close up and 'in your face.' Colour saturation is neither here nor there, really, in the sense that it's a one-slider adjustment and personal anyway. Super image. You seem surprised by colour gradients and so was I when I started. Ours is a site which can hit SQM22 so where do they come from? I've stopped asking because I have no idea, but they are almost always there. Although I greatly prefer Photoshop for most things I run Pixinsight's DBE on colour pretty much without exception. Also SCNR green. Why does green come out too strongly? Not a clue! Again, I've stopped asking. Anyway, bravo! Olly
  2. ollypenrice

    Bodes Galaxy 15hr Lum

    Nicely done with restrained processing and plenty of data. That's the way. Olly
  3. Nah, we didn't steal it. C'mon, it goes through Greenwich, right? And where's Greenwich? Rest my case.
  4. ollypenrice

    Prints on aluminium.

    I've had a few prints done on plexiglass and been pretty pleased with them but I've just received one done on aluminium by these people: https://www.monoeuvre.fr/photo-sur-aluminium-offre/?gclid=CjwKCAjwmJbeBRBCEiwAAY4VVdMfttXu4RSNsCrcrOvFy_WTp-4sq_aRxj0CTIf_vo5GDzEAfSb3-hoC7dgQAvD_BwE&ia-pkpmtrack=1-9333538363834363134303-86791857-3413617617-77063989857&ef_id=CjwKCAjwmJbeBRBCEiwAAY4VVdMfttXu4RSNsCrcrOvFy_WTp-4sq_aRxj0CTIf_vo5GDzEAfSb3-hoC7dgQAvD_BwE:G:s It is the closest thing I've ever seen to an astrophoto on a PC screen. There's a very high gloss for the surface, tiny details are rendered sharply and, unusually, the signal just above the background sky has been rendered easily visible. Colour fidelity is perfect. I would give this firm ten out of ten. Simple as that. A 30 x 40cm print cost about 24 Euros delivered and it came quickly and very well packaged indeed. I did give the image a tweak in TIFF format prior to sending the large JPEG to them. In Curves I fixed the background sky with a point right on it and one below it and then lifted it a tad just above that. I then pulled the top of the curve down just a bit as well to prevent any white clipping. To give you an idea of the final levels, based on experience/guesswork, the version I sent them looked as shown below. Clearly this would not be the right Levels for a PC screen presentation but I felt it came out just right on the print. The dedication lower left is to an old school friend who kindly sent me a copy of a book he's recently written about an obscure corner of motorcycle racing history. Very good it was, too! Olly
  5. There certainly are dark sites in southern Spain but, as with Provence where I live, you have to look for them. In Spain the coast is out of the question but high up and inland there are great places. Before choosing Provence I scouted extensively in Spain, which I knew well from thousands of miles of cycle touring. In any developed country the devil is in the detail. Mountain tops are not the place to be. It's better to have an elevated site ringed by slightly higher ground since this offers a light baffle and protection from the wind. What is reassuring is that even in a mainland European country you can, if you search carefully, find sites with a zenith SQM that can reach 22. I'm not sure why there are not more astronomy providers than there are. Several have appeared and disappeared in the fifteen years that I've been doing this. Marc and Hélène Breton run a massive operation quite near to my place but the setup is entirely different and I don't try to compete with their multi million Euro telescope! They are good people, though. http://www.obs-bp.com/ I guess not everybody wants to live in the the kind of place that's suitable. Personally I love doing so but I'm bonkers... lly
  6. That really is a great result. While shooting the colour I'd take a short set of RGB at significantly shorter exposure so as to fill in the Trapezium. You'll be at very high SN on this bright region so there is no point in shooting L or a lot of subs. You could then follow this excellent tutorial on how to blend the long and short. http://www.astropix.com/html/j_digit/laymask.html Olly
  7. ollypenrice

    Rosette complete

    Version one is shouting, version two is not. No brainer for me. Olly
  8. ollypenrice

    NGC1333 LRGB

    Although I've yet to try it some good imagers I know do DBE separately per channel. Any thoughts? Olly
  9. ollypenrice

    SW Esprit 100ED Focuser

    Does the separation of the tight spots correspond with one full rotation of the pinion? If so the drive shaft my be slightly bent. Olly
  10. ollypenrice

    A reliable green laser?

    For years I used a nice stainless steel one from Galaxy Products but I can no longer find them. The black bodied ones with a metal end that cost 10P on the net are a liability. One guest got a significant burn from his and they are terribly unreliable. I hope someone comes up with a good one because they are so useful. Olly
  11. ollypenrice

    NGC1333 LRGB

    Yup, I'd forgotten that but I've found them. Thanks Vim. Olly
  12. ollypenrice

    NGC1333 LRGB

    Could be DBE if the markers were right on the edge. I've found my original data and will try a reprocess since this is an interesting problem bit of sky and my existing process is whacky. I've been obsessed for some time by a research project from my other life in English Lit., so it will be good to work on a picture. Olly
  13. ollypenrice

    NGC1333 LRGB

    A few thoughts: firstly you have some quite broad edge artefacts, I think. Scan round the edge of the frame to see if you agree. When I get these it is from the need to stretch to a manic degree. I got them when struggling to find the 'Fabian Neyer' Ha background to the Double Cluster, for instance. I guess I agree that there could be more signal for the time given but, as pointed out earlier in the thread, LP could be adding to your difficulty. Maybe this just is a dark sky target. I don't know because I've never imaged anywhere but where I now live, which is very dark. I'm also not sure about the magenta zones. I didn't find them in my shoot but I see magenta patches creeping into some posted images. They are not in consistent locations, though, which suggests they are an incipient processing hazard in this target. I really don't know. Olly
  14. ollypenrice

    NGC1333 LRGB

    We did do the colourful nebula close up in the 14 inch but not with enough data for a full size presentation. It was gloriously colourful when presented small, though, and that data finally went into my widefield from the Tak 106/Atik 11000. At some point in the processing of that data I got too much brown in the background but long subs in the CCD didn't suffer too much from noise. I think I had similar exp. time to Rodd. I'll see if I have the original widefield data but I suspect I'll have canned it. Olly
  15. ollypenrice

    Change of Targets M33

    At the top right of the main page click on your username and then choose Settings. Signature is in a box on the left of this page. Olly
  16. ollypenrice

    Esprit 120 part 2

    You've got me worried now! I can hardly see anything which fits this description... Very bright stars throw up artefacts in most refractors, indeed in most telescopes. In the scheme of things I'd call these very clean. Takahashis throw up their signature 'inverse lighthouse beams,' for instance. Another source can be the microlenses on some chips. Nothing to do with the scope. Olly
  17. ollypenrice

    Change of Targets M33

    Good work on the coma by Alacant. If you put your kit in your signature we can advise on what you might do about it at source. So much is right about this image but I have to ask, again, about flats. Both this and your M45 have a hint of vignetting to my eye. Olly
  18. With as many subs as this, and unguided (so given natural dither) I'd be inclined to try stacking without darks at all. I'd try a master bias instead of a dark. I don't even use darks with a set point cooled CCD because I get cleaner results without them. Olly
  19. ollypenrice

    M45 Around 3 hours

    It is going well. Are you using flats? Olly
  20. I'd like to sit down with John Barrow and talk about science and religion but I gather from people who know him that he doesn't do that. Olly
  21. ollypenrice

    California nebula.

    Really nice to see it all. Olly
  22. ollypenrice

    California nebula.

    Yes, it's huge. Here's the OP's image superimposed onto a widefield which, itself, doesn't quite capture the whole lot. Stu, I don't know if you model your imaging projects on a planetarium before deciding on whether to go for them or not but it can be a big help to do so. I do it in SkyMap Pro but other planetaria let you do it. You have to set your your focal length and chip size first then you can drop them onto the chart to see how they frame up. Olly
  23. ollypenrice

    Another question about imaging Pleiades!

    I think that fear of blowing out the cores is over-stated, not just in the case of M45 but for many other targets. Personally I'd be thinking in terms of 10 minutes, though I haven't used my 460 on M45, only my 11000 with greater well depth. This is from our dark site so LP may limit you, of course. If the cores do over-blow they are an easy fix with a handful of 30 second subs in RGB to 'fill them in' using a layer mask. No need for short luminance. Build the LRGB up with blown cores first then they layer mask the short RGB into that. Under no circumstances would I shoot extra blue. You'll have plenty of that. The elusive part of this target is the ERE (extended red emission). I often push the idea that longer subs work well and don't blow out bright regions as much as is widely assumed. Take at look at your linear subs to assess this. The size of the stars in the linear subs is the size they can be in the final image if you process carefully. I could have held the stars down harder here but decided to give them an honest brightness. With CCD long subs go deep. Worth a try. I have that 100 best targets book as well but I promise you I take no notice whatever of its timid ideas on sub length. I'm a fan of the 30 minute luminance sub... Olly
  24. No. I can't speak for what others are saying but that is certainly not what I'm saying. What I'm saying comes in two parts. 1) You do have to capture the Ha signal in order for it to appear in the image. That is hardly controversial.* 2) In order to isolate the structures unique to Ha you need to run your Ha sensitive camera through an Ha filter which blocks other signal. It is this process which enhances contrast. In my own imaging I'm trying use an Ha layer to find faint Ha signal and high contrast in Ha structures to enhance a broadband image. I don't advocate what Neil calls 'a one true way' but what I'm trying to do is think through the consequences of 1) high Ha sensitivity and 2) the isolation of purely Ha signal. Olly * Edit for further clarification: my luminance filter passes more Ha than my 3nm Ha filter and so, in all probability, does my red filter. What my Ha filter does do is allow me to expose for longer to catch more Ha and only Ha. Three channel processing then allows this additional signal and additional contrast to be incorporated into the image without turning everything red. Capturing ever greater amounts of broadband while simultaneously capturing ever greater amounts of Ha is not the same.
  25. ollypenrice

    Bought the wrong item?

    Very good... lly

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