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Roy Foreman

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About Roy Foreman

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    Nebula

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  • Gender
    Male
  • Interests
    Deep sky astro imaging
  • Location
    Minehead, Somerset

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  1. It's one of the reasons I keep to short exposures, We actually had the first clear-ish night a couple of days ago, and it was a case of take a shot, wait for the cloud to pass, take another, wait for the next cloud etc. If you are doing 5-10 mins and that cloud comes when you're half way through ..... It;s good to know I'm not the only 'going slowly insane' astronomer around !!!
  2. Yes I agree - using higher ISO is like turning up the brightness at time of capture rather than in processing. Never tried taking side by side images at ISO 200 and 6400 for the same duration and then processing each to see which reveals most detail / less noise. When I get a chance I'll try it. I've done it with 1600/6400 and the 6400 turned out less noisy. Can't show you the results of that because I since discarded the images as being below par.
  3. To reply to the above few posts in one hit - firstly the D810a is not like a regular D810. The lowest ISO setting has been raised from 64 to 200, so the sweet spot is probably higher at something like 1600. I seem to remember reading that somewhere. A 60 sec exposure at 1600 could probably be pushed to look like a 60 sec exposure at 6400 but I've never tried it. I have taken images of star clusters at ISO 200 and they can be pushed quite dramatically, but nebulae are not quite so forgiving. Most modern cameras perform really well at high ISO's these days, and my personal preference is to kee
  4. My camera is a Nikon D810a and is designed for astrophotography, so I think nothing of using ISO 6400 on a regular basis. Other cameras may not work so efficiently at these high ISO's, but I would suggest most would give decent results at ISO 1600. The advantage of high ISO's is shorter exposure times, which is an advantage when making the most of short imaging windows in the weather, as I often have to. Here is an example of an ISO 6400 image :-
  5. There is a trade off with ISO settings. Low settings like 200 will give higher quality and can be pushed further during post processing to bring out details, but will require longer exposure times. Higher settings like 6400 will reduce your exposure times quite dramatically but will produce a lot more digital noise. Generally you can offset this but taking several identical shots and stacking them together (I usually take 5 or 7) in photoshop. As a guide for the Pleiades, try 5 x 60 sec at ISO 6400 and see what you get. Let us know how it turns out
  6. I too am driven to despair with the weather. I have a brand new and very expensive RASA 11 that has been waiting 4 months to see first light. And it's still waiting. Sometimes I think 'why am I bothering with all this', Then, when eventually the skies do clear, I know exactly why I bother - astronomy is in my blood and has been all my life. If it really is in your blood you will endure all the aggro alongside the pleasure you get from being under the stars. As others have said, clear skies will return soon !
  7. Thanks for the welcome Jeff ! I have seen the sun on occasions recently, but not clearly enough to consider looking at it through a solar scope - yes I have one too. I keep a log of the night time weather - have done for several years - and here in West Somerset, the last time we had skies cloudless enough to consider deep sky imaging was 21st September 2020. That borders on unbelievable. The forecast for tomorrow night, Saturday is for clear skies from 11pm until 3am. I shall be staying up to witness this incredibly rare celestial even, but I expect it will be clouded out as us
  8. Thank you Dave - the warm welcome is much appreciated !
  9. Roy Foreman

    Roy Foreman

  10. Thank you Nigella - yes there have been sunny days but no clear nights, great for your solar work ! Already done time looking at the RASA, now I need to make some modifications to it before first light. Those Losmandy rails top and bottom have just got to go. Really hate dovetail mountings on larger scopes, so I replace them with a setup that is much easier and safer to use.
  11. So I'm not totally to blame then, you have contributed to the rubbish weather as well by getting a new scope. Please don't give up on Astronomy - although I know the feeling well ! You are right - the weather will improve one day. Good things are worth waiting for, as they say. Good luck with the new scope when it finally gets first light !
  12. Thank you Les for your jovial response - made me laugh. I do get the feeling that bad weather seems to follow me around, so I suppose I must take some credit for it all. Having an observatory helps - I can be ready to go in 5 minutes if there is a break in the clouds, but we are not even getting that at the moment. At least the spring and summer just gone provided many clear nights, it just meant staying up until 2am !!!
  13. Thank you both for the warm welcome ! In times of prolonged cloudy weather I often cast my mind back to a holiday I had a couple of years ago in North Africa. It included a couple of nights in the Sahara Desert. The skies there are to die for. The stars, and the milky way, go right down to the horizon undiminished. It was so dark I could not see a hands length in front of me without a torch. I had taken some rudimentary imaging equipment with me, but polar aligning was a problem. Here in the UK it's easy to find Polaris - it's the brightest star in that part of the sky. Not so
  14. I have an EQ6 EQ/AZ which is very similar, and I totally agree with your sentiments. It will track unguided for 60 sec at 2m focal length (8" SCT) with very decent results. Sad you had to part with yours - maybe one day you will own another one ?
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