Sigma Zoom Lens (Large)

[AstroTasmania]

Hi,

Here is a link to an interesting 15 kilogram f/2.8 200mm to 500mm lens.

Just for general interest, I am not suggesting its suitability or otherwise for astro work. I have real apo scopes and prime non zoom camera lenses for that.

http://www.newsgather.net/index.php?cu=070308183915

http://www.dpreview.com/articles/pma2007/Sigma/IMG_5383.jpg

Clear skies...

PS - I am not planning on buying one.

[Radar]

Holy cow!

Are you planning on getting one Shev?

That would take some nice shots.

[phoenix]

Hey Shevill

Geez thats the biggest lens i've seen !

I reakon you would need a crane to hold that one up lol

What would that be worth shevill ?




Cheers Jason :pipethinker:

[Tenacious Del]

That lens is like a suitcase. I'd hate to think how much that it is worth.

[Draig]

Hi All,

I will admit one of the things I hate about magazines (and I am afraid to say that they all suffer from this) is poor print/page colour/background image colour setup.

What I mean is a black print on a blue page with the printing then running over the top of a dark image. Combine that with a glossy page and it is almost impossible to see the print yet alone read it.

By the way (now that I have finished my rant :Chessy_Smile: ) nise phot of McNaught there Dave. How long was the exposure for to get shuch a bright comet?

Cheers Colin

[Dusty]

I'm not sure if you're being serious about buying this lens Shevill, but I'd highly recommend other lenses for astro work instead.
The very best lenses to use if you want to improve on your astro imaging are prime lenses.
For a fraction of the cost of the lens you mention, I bought a Canon 300mm f/2.8 L.
It's one of the very sharpest lenses Canon make (see attached MTF chart).
It utilises one fluorite element and two UD-glass elements and even if you attach a 2x TC, giving you a whopping 600mm on a FF body, it will still yield sharp astro images even though it looses 2 stops.
This combination is vastly more practical and easier to handle.
I've also attached an image I took at Lostock of Comet McNaught using my old 300mm f/4 IS and a 2x TC on my Canon 20D.
The 300mm f/2.8 would yield even better quality.





By the way (now that I have finished my rant :Chessy_Smile: ) nise phot of McNaught there Dave. How long was the exposure for to get shuch a bright comet?

Cheers Colin

Hi Colin, I assume you mean my McNaught image?
It was an 8 sec exp, at f/8 and ISO 400.

Cheers
Dusty

[h0ughy]

what a waste!! you need a crane to move it??