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Author Topic: Supermoon  (Read 1974 times)
martin
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« on: August 10, 2014, 11:41:16 PM »

taken a few minutes ago..........


* supermoon.jpg (64.37 KB, 832x638 - viewed 299 times.)
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dhaslam
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« Reply #1 on: August 11, 2014, 10:35:40 AM »

That is very good for a 200 mm lens.   I should be able to get  better than this with 500mm.   


* SMoon.jpg (93.47 KB, 700x680 - viewed 268 times.)
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martin
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« Reply #2 on: August 11, 2014, 10:44:34 AM »

Can't justify anything longer than the 200mm these days, I'd never use it for anything else.........at least it's the equivalent of a 300 on 35mm. Much more detail and sharpness in your picture!
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desperate
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« Reply #3 on: August 11, 2014, 02:34:54 PM »

Nice piccy Mr D Haslam, the rays radiating out from Copernicus near the centre bottom and the terminator right at the bottom stand out really well, and almost no colour, that must be a well corrected lens you have.

The trick with planetary photography is to take a lot of short exposures to see "through" the atmospheric turbulence and then stack the best images in GIMP or Registax, also that technique dodges the worst of the light pollution.

I have my replacement astronomical camera now so I cant wait to play with it..............just need a clear night fingers crossed!

Desp
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dhaslam
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« Reply #4 on: August 11, 2014, 05:50:41 PM »

The lens is a Sigma 500mm f4.5  but is the old  pre digital version and is something like 30 years old.   New they cost  about $5000 and I paid  about 1000 for this one from Japan.   Not having the newer coatings means a bit of loss of definition on low contrast or bright subjects.     I was very disappointed with a similar focal length astronomical lens and but I may use it as a tracker  for this lens.    Astro photography  is not for the faint hearted.   
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DHW 250 litre cylinder  60 X 47mm tubes
Heating  180,000 litre straw insulated seasonal store, 90X58mm tubes + 7 sqm flat collectors, 1 kW VAWT, 3 kW heatpump plus Walltherm gasifying stove
desperate
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« Reply #5 on: August 11, 2014, 06:11:16 PM »

Nice piece of kit, my mate is drooling over one of them, mind you he is still getting over the shock of buying a 7D  horror

You would be better off getting a RC reflecting telescope instead of a lens I would have thought, no colour aberrations to worry about, 1300mm focal length at prime focus, and with eyepieces any effective focal length you want. 15cm diameter primary mirror for lots of light grasp and all for about 450 quid. Do you have a good mount for astrophotography? if done properly, that's where the costs really add up.

I have a 300mm F4.5 newt I should get rid of if you fancy a nice big light bucket??

Desp
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« Reply #6 on: August 11, 2014, 06:46:26 PM »

 The problem with photography is that you need a good  ratio of aperture to focal length, otherwise exposure times are too long.   I have a motorised mount but  it needs the  electronics to make it work.   
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DHW 250 litre cylinder  60 X 47mm tubes
Heating  180,000 litre straw insulated seasonal store, 90X58mm tubes + 7 sqm flat collectors, 1 kW VAWT, 3 kW heatpump plus Walltherm gasifying stove
Ivan
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« Reply #7 on: August 15, 2014, 10:45:06 PM »

Anyone manage a photo of the International Space Station. I tried a few times,but just got a wobbly white streak.
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