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ollypenrice

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Everything posted by ollypenrice

  1. ollypenrice

    ngc 7789

    I've tried with your colour a couple of times (just on the screen grab) but never found a satisfactory solution. I don't know how you see it but to my eye the blues are too cyan and reds too orange or yellow-orange. I'd be happy to run the TIFF through PI's colour calibration. I know you don't use PI but it would be interesting to see if it could fix it. There are various routines for colour calibration in PI but the most interesting is the photometric version which identifies the object and uses the astrophysics of the target to set the colour. I still think that in a target with faint nebulositiy you'd be losing data. Olly
  2. As Wim says, no IFN here. The IFN is much harder to find and even harder to find in colour. However, the dusty features you've brought out are in good agreement with those of my very long exposure M45 so we can't both be inventing them! (I'm always wary of 'creating' features in the faint stuff so comparing one's results with others is a good idea.) Olly
  3. The first thing I'd do is make a stack without the flats. This has most of the hallmarks of over-correction, with some oddities thrown in for a challenge. Maybe give the no-flats image a stretch but nothing else and post it up? The fact that you did your flats as usual doesn't mean they can't be wrong. The blessèd things have a mind of their own! Olly
  4. It's certainly true that the seeing often over-rides the best efforts of the mount in high resolution imaging. I'm glad our EQ6 delivered the goods for you! It didn't do quite so well the week before last but there are any number of variables in a temporary setup. Maybe I err too much on the side of caution regarding tracking. It's just so exasperating when it won't deliver. If the OP isn't going to image with the C9.25 you have a good point here. I'm still not ready to jump ship from CCD to CMOS, though. Olly
  5. ollypenrice

    ngc 7789

    What programme is this? The histogram you're showing in Curves is partially hidden on the left by the white dot at the bottom of the Curve line. To my mind the Levels histogram I took from Photoshop clearly agrees with what we see in the image. The sky is a featuresless jet black with a value ranging from 9 to 14. There is no background value we can deem to be 'correct' but most imagers are looking for values between 20 and 23, the most experienced erring towards the higher value. Of course, we're dealing with the JPEG here. It would be interesting to experiment with the linear TIFF. Does your programme allow you to view the histogram in Levels? Olly
  6. ollypenrice

    JamesF's observatory build

    I pick mine up on the Duster's roof rack. Just be careful to prevent the sharp edges from sawing through any tie downs that you use. This certainly happens, as I know!!! I've used flat steel sheet on our summer kitchen's fixed parasol but you have to bolt it down only at one end and hold the rest down under wooden or steel strips which allow it to expand without buckling. Why does corrugated steel not buckle along its length? Maybe it tries to but the corrugation simply prevents it. Expansion in the other axis can be absorbed by deepening the peak to valley, of course. This is a great observatory in the making. Olly
  7. ollypenrice

    ngc 7789

  8. ollypenrice

    Refractor For Galaxy Imaging

    Alas, Gav, there I cannot help you and I doubt that anyone can! lly
  9. ollypenrice

    Refractor For Galaxy Imaging

    Heh heh, so would I! However, the Esprit 150s in captivity have been producing very good stuff. Your guiding RMS in arcseconds needs to be about half (or less) your image scale in arcseconds per pixel otherwise you will not be resolving at the theoretical values of the setup. This simply means that you could use a shorter focal length, have a wider field of view and produce exactly the same level of resolved detail. At O.78 arcsecs per pixel you need a guide RMS of just under 0.4 arcsecs by rule of thumb and best guess. Our Mesu 200s can deliver this reliably. The sky can't always deliver the seeing to support it, which means we shoot RGB until it bahaves itself. Will an EQ8 run reliably at 0.4arcsecs? We need the owners to tell us. Olly
  10. ollypenrice

    Want to get new refractor

    I'm a great fan of the TEC140 both for visual observing and for imaging. Their QC is very high and the instrument performs beautifully. The FT focuser probably can't be beaten. However, there are lots of other great Apos. Olly
  11. ollypenrice

    M33 - 400 min.

    I think that's a very good capture and I suspect it has quite a lot more to give. Adam's reduction in green was certainly a good move. I think you could find more colour, too. Keep away from the Saturation slider if you can. In Photoshop you could try these: Make 2 copy layers. Set top layer to blend mode Soft Light and flatten onto mid layer. Set blend mode to Colour and flatten. Convert to Lab colour in Image - Mode. In Channels activate 'a' channel then go to Image, Adjustments, Brightness and Contrast and increase the contrast by a large value like 35. Then do exactly the same for 'b' channel. Return image mode to RGB. These are low-noise techniques for intensifying colour. Olly
  12. ollypenrice

    My second Andromeda of the season

    An unforced image which looks superb. Olly
  13. ollypenrice

    M33 WIP now with DSLR colour

    Terrific. M33 can often look flat and featureless but this is crackling with contrasts at all scales. An image with attitude! Olly
  14. ollypenrice

    IOptron iEQ45 pro OR Skywatcher EQ6-R

    One way of describing iOptron is to say that they are continually improving their products. The other is to say that they don't test them properly before releasing them in the first place. Olly
  15. ollypenrice

    The Great Andromeda Galaxy

    No, if you'stretched' the image (as you surely did) the natural dynamic range was not preserved. The best approximation of the natural dynamic range is to be found in the linear image but, as we all know, that will give us very little to look at. It's a very nice, clean and well balanced M31 though, and I think it looks great. Few people get such nice tight little stars from a Hyperstar. Very impressive. Olly
  16. ollypenrice

    Had enough

    Anything I can do manually I do manually. Focus, flip, framing. Since 99% of failures are due to software I find it makes sense. Olly
  17. ollypenrice

    Oh God is this the Future?

    I just heard this horror story on France Inter, the serious French radio channel, so other outlets are running it. Nightmare. Olly
  18. ollypenrice

    Do I need to change my ZWO RGB filters too?

    In the top right corner of the colour image we may be seeing part of a large circular reflection in blue, I suspect. I'd certainly try a different filter if possible. Olly
  19. OK, my view is that, for the C9.25, it can't be done. We don't just have to worry about weight but about tracking accuracy which is proportional to the image scale in arcseconds per pixel. To do DS imaging reliably with this scope, and to produce results in which the captured resolution approaches the theoretical resolution, you'd need a Mesu 200 mount. (In my book this is the best mount in its class and the cheapest. I run two and host three others. To clear, I've no commercial connections of any kind.) The mounts within your budget are of variable quality in terms of tracking accuracy (PE and Backlash) so it's hard to give chapter and verse on what guiding accuracy your version might deliver. Whatever the RMS in arcseconds the mount delivers needs to be about half the image scale in arcseconds per pixel. On excellent nights our EQ sixes can run at just below an arcsecond but this is a best value and they're not entirely consistent. Now I think this is very good for the price, but will it support DS imaging with a C9.25? I'd be surprised if it would. It would be good to hear what kind of RMS values others find with their EQ sixes. Ours are not in nightly use any longer so my data is patchy. Olly
  20. ollypenrice

    Had enough

    I've got to the point where I expect it all to work when I turn it on and it usually does. I'm useless with all things IT but I did reach that point - which means so can anyone. Olly
  21. ollypenrice

    Upgrade mount or start autoguiding?

    Essentially it has to work. It is no different from the classical drift method except that in the classical method you watch the movement of the star over time. In the DARV method you track the movement of the star over time while it is leaving an 'out and back' trace to help you be sure what's going on. Olly
  22. ollypenrice

    Upgrade mount or start autoguiding?

    Or a filter for the guide camera? Olly
  23. ollypenrice

    Atik sofware/driver issues

    I find connection of the EFW2 somewhat pernickety. It is sensitive to the order in which you do things, so start with the camera and wheel disconnected, start the PC, then start the camera and wheel and lastly plug in the USBs. If you do find the wheel won't run in Artemis you do have a second resort: you can run it in Filter Wheel Runner which is part of the Artemis suite and, presumably, intended for those using an EFW2 with a non-Atik camera. We've had the .net3.5 support message in William's thread above, too. Olly
  24. That's surely been stretched. As you suggest, I think you'll have applied something somewhere along the line. If not the filter has a problem. Olly
  25. ollypenrice

    Upgrade mount or start autoguiding?

    Autoguiding is the life-blood of astrophotography. As soon as you approach telescopic resolution you need it. (Let's ignore the encoder-guided mounts which are clearly way out of an HEQ5 budget.) The trouble is that the SA is only equipped with a single axis guiding option. With perfect PA theory says that no guiding in Dec should be necessary. Experience, however, says that it is. Nevertheless, given the high standard of your images (indeed very high) single axis guiding would be surely a big bonus and you could keep the autogiuder when you move up to a larger mount. (As I suspect you will because you've clearly gone into all aspects of AP carefully in order to produce results as above.) Autoguiding turns a £1000 mount into a £10,000 mount for most purposes. It's inexpensive, elegant, easy and effective. On top of that the best software is free. Just do it. I'm not sure about your PA procedure. Polaris contains virtually no useful information about RA because it is so close to the pole as to describe only a tiny circle during the sidereal day. I suspêct that the DARV method might serve you well: https://ideiki.com/astro/usersguide/darv.htm Olly
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