Wider Coal Sack

[xelasnave]

Originally Posted by bojan

Oh yes... that one is almost perfect.

What could be the purple band at the bottom?
Mirror vignetting?

I use a little baffled dew tube as am am convinced it helps keep stray light off the lens and hopefully minimises reflections...it can however get in the way of the light coming in if its not on properly and the purple may be attributable to it being in the way.
Alex

[xelasnave]

Thank you JA for taking your time to educate me on the len pricing and performance.
Fortunately I am happy with things so far or not unhappy enough to go into $2000 bracket.
I am considering (today so this could change tomorrow) a Pentax full frame ca.era and noticed a lens around the $800 mark which I thought probably worthwhile when , if I buy that camera.
Its 50 to 200 I think and that range appealled because I really like wide fields ...the wider the better with the Milky Way.
What I would like to do some day is to narrow band a wide field as I think that could be something.
Plus I would like another camera maybe to poggy back when imaging thru say the 80 mm scope...it may cause vibration issues with two cameras clicking away but that is sort of the general idea.
Alex

[raymo]

Alex,If I, an octogenarian, am a nimble young fella, how old must you be
for goodness sake?
raymo

[xelasnave]

Originally Posted by raymo

Alex,If I, an octogenarian, am a nimble young fella, how old must you be
for goodness sake?
raymo

Well I am only 71 years old but I was born at a very young age.

My legs are a problem Raymo...I had a back problem which threatened to make me drive a wheel chair and although the operation was a sucess my legs still burn non stop and generally add a century on how I feel.

The numbness in my feet would cause me to topple if I tried your suggested acrobatics.

I could rotate the image in gimp which I should do to make you happy by presenting an upright cross.

But I decided to stop processing a little while ago as I was in what may be my future home and observatory, a little shed that has a good power supply, but I looked up and there was a little snake in the rafters above me...it put me off so I packed it in and came down to the house.

I think its only a green snake but as I cant tell green from brown I work on the basis it could be a brown snake...and even a little one can kill you and I want to avoid that.
Alex

[JA]

Originally Posted by xelasnave

Thank you JA for taking your time to educate me on the len pricing and performance.
Fortunately I am happy with things so far or not unhappy enough to go into $2000 bracket.

I wasn't suggesting you were or should be unhappy with the lens. I think the 55-200 is a very sharp lens, that I have recommended with some other DX lenses quite a few times. My real point was only that the 70-200 isn't a 55-200, nor does it have the $200 ish price tag.

Originally Posted by xelasnave

I am considering (today so this could change tomorrow) a Pentax full frame ca.era and noticed a lens around the $800 mark which I thought probably worthwhile when , if I buy that camera.

I think some of those Pentax DSLR models are excellent and the astrotracer function could be very useful in travelling light in the field by using a fixed tripod. Also their pixel-shift function (models?) can be useful for ultrahigh resolution still images. I'm not sure if it could be used well with the astrotracer function, but might offer some benefit on a tracked mount (test required). It would be wonderful to see this implemented in the other major brands as well.

Originally Posted by xelasnave

Its 50 to 200 I think and that range appealled because I really like wide fields ...the wider the better with the Milky Way.

I'm Not sure if you are referring to a new lens for your possible new Pentax or your current Nikon 55-200 DX lens. If you want a little more reach at the same quality level there is also a Nikon 55-300 DX lens. Also excellent and very well priced. Second hand they are almost for free

I don't recall if it was a 55-200 or 55-300 (EDIT: Just checked it was the Nikon 55-300MM F/4-5.6 AF-S VR DX), but Diego, one of our members here used one with an astrocam, motorised focus, filterwheel setup, etc, that was remarkable in nice tiny-ish stars, sharpness and lack of obvious abberation, just that given its relatively modest aperture for a 55mm lens (f/4) it would require longer exposure than your typical 50mm-ish prime lens.

I will see if I can link it for reference....
EDIT: see ......
http://www.iceinspace.com.au/forum/s...on#post1342739

Best
JA

[raymo]

I can sympathise with you Alex, I had a horrendous 175kmh motor cycle bingle some 57 yrs ago, which brought an abrupt end to my career of choice, and left me with chronic back and hip pain.
raymo

[xelasnave]

Thanks JA
That feature to follow the stars could be handy and I bet I could make a go of it with short exposures , high iso ( high iso is not as noisy as I remember...I use 1600 mostly now although I tried a 400 iso on Omega C the other night whilst waiting for the lobster to climb out of the trees...and 400 iso did not seem to offer any noticable benefit..yet I have to go back to it as I got tired up with the lobster neb and up to now forgot about the Omega images...I did stack them but the final image from dds did not hrab me because the center was burnt out...so I did not bother to process it...if it gets cloudy I may try..oh it is cloudy what a surprise.
I have had a few goes going up to 3200 iso and I think even the next up and those seemed ok...depands on what the noise is in the K1 (?) Pentax but static would be great.
I would lie to be able to demonstrate and encourage folk considering astro photograpy by demonstrating a relatively cheap entry level via camera and a tripod.
Alex

[xelasnave]

Originally Posted by raymo

I can sympathise with you Alex, I had a horrendous 175kmh motor cycle bingle some 57 yrs ago, which brought an abrupt end to my career of choice, and left me with chronic back and hip pain.
raymo

Wow 175 kph..I have never been over 165 on a bike...a road not dirt bike..moto cross was never over 110 in the straight...but I have come off at between 80 and100 kph more times than I can remember..pretty routine in moto cross and never broke anything fortunately.

And the funny thing at a track riders would have the same sort of crash in the same corner as would I ....they would get broken legs and arms but I never did...very sore but no broken bones.
Very lucky guy I am.
Alex