View single post by Robert

Posted: Thu Aug 29th, 2019 04:36

Joined:	Mon Apr 2nd, 2012
Location:	South Lakeland, UK
Posts:	4066
Status:	Offline

Thanks JK, my setup is maturing, I will take a look a the UV power Pack later that will make the setup tool-free, quicker, easier and safer, I'm not keen on taking lead acid batteries into the field, in the dark, clambering over gates and suchlike. Also it would make it easier (lighter) to take the rig to less accessible locations, although the astro head is by far the heaviest and most cumbersome bit.

I went out last night but as soon as I parked up the clouds came rolling in. We have windmills in the hills nearby, I had intended to use a couple as a feature with the Milky Way behind but it was not to be. I want to get a feel for the exposure using the MC-36, it's a totally different technique because it allows me to close the lens down some and reduce the ISO to much lower levels. I still need to assess that compared with wide open lens and high ISO but shorter exposures. I suppose it's a bit like birders and TC's or longer lenses. The 16mm seems to improve about f/8.0, wide open the stars towards the outer edges of the image seem to take on a triangular appearance with severe CA. The triangles seem to point towards the centre of the image. I haven't noticed this with the D3 but the higher resolution of the D800 reveals it clearly, so that is another reason to stop down some. The lower resolution of the D3 largely masks the effect.

There are no clear skies forecast for the next week or 10 days, beyond that it's anybodies guess, by then the moon will be bright again. o.O

____________________
Robert.