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Roy Foreman

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Everything posted by Roy Foreman

  1. I recently used SharpCap to polar align my EQ6 and I have to say I was impressed by how quick and easy it was to do. As you probably know the software provides two methods of adjusting the PA. The first is by adjusting the mount until a highlighted star - later two parallel lines - coincide with each other. The second is by watching the RA and DEC offsets reduce in magnitude as you adjust the mount. If using the latter method it is important that SharpCap knows your latitude and longitude for accurate results. I managed to get my PA down to 25 arc sec, and the reason I could not get better th
  2. From the album: Roy Foreman

    M108 Galaxy in Ursa Major 11th April 2020 16" F/4.5 Reflector Nikon D810a 5 x 30 sec at ISO 6400 IDAS LPR Filter Processed in Photoshop and Astro Flat Pro Imaged through very hazy skies
  3. Roy Foreman

    Roy Foreman

  4. From the album: Roy Foreman

    M81 and M82 Galaxies in Ursa Major 11th April 2020 16" F/4.5 Reflector Nikon D810a 5 x 120 sec at ISO 1600 IDAS LPR Filter Processed in Photoshop and Astro Flat Pro Imaged through very hazy skies
  5. Very nice and well done. Here in the UK we can only dream of such imaging targets !
  6. I have been waiting over four months for a clear night with no clouds and no moon. According to my records 21st September 2020 was the last time I was able to do any deep sky work. I live in the southwest. Summer 2020 was, however, very productive, but it did mean waiting until 11.30 pm to start imaging !
  7. From the album: Roy Foreman

    Copernicus and Eratosthenes 24th January 2021 16" F/4.5 Reflector ZWO ASI 183 MM UV/IR cut filter 500 frames at 16 fps Selective enlargement from prime focus image
  8. From the album: Roy Foreman

    Plato and Mare Imbrium 24th January 2021 16" F/4.5 Reflector ZWO ASI 183 MM UV/IR cut filter 500 frames at 16 fps Selective enlargement from prime focus image
  9. From the album: Roy Foreman

    Clavius and Tycho 24th January 2021 16" F/4.5 Reflector ZWO ASI 183 MM UV/IR cut filter 500 frames at 16 fps Selective enlargement from prime focus image
  10. From the album: Roy Foreman

    Copernicus and Eratosthenes 24th January 2021 16" F/4.5 Reflector ZWO ASI 183 MM UV/IR cut filter 500 frames at 16 fps Selective enlargement from prime focus image
  11. Very nice shot. Clavius is my favourite crater. I always assumed a red filter was the one to use to minimise the effects of atmospheric turbulence, but your shot through a blue filter has worked really well.
  12. Presumably a very tall one !!
  13. 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 !!!
  14. 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.
  15. 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
  16. 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 :-
  17. 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
  18. 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 !
  19. 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
  20. Thank you Dave - the warm welcome is much appreciated !
  21. From the album: Roy Foreman

    The Moon - 3rd January 2020 Selective enlargement from full frame image 16" F/4.5 Reflector Nikon D810a 1/320s at ISO 200 Processed in Photoshop
  22. From the album: Roy Foreman

    The Moon - 3rd January 2020 Selective enlargement from full frame image 16" F/4.5 Reflector Nikon D810a 1/320s at ISO 200 Processed in Photoshop
  23. From the album: Roy Foreman

    M5 Globular Cluster in Serpens 8th June 2020 16" F/4.5 Reflector ZWO ASI 294 MC 12 x 30s at gain 360 Sensor Temp -10 C No Filters
  24. 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.
  25. 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 !
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