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05-08-2009, 10:06 AM   #31
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QuoteOriginally posted by AntiBad Quote
Yes, I suppose sigma does make something that sounds close, but the 20 and 24 are really kinda big and shouldn't a crop cam lens be a bit smaller than that
Not necessarily. Although sensor size is one factor that affects lens size, another factor is the distance form the lens mount to the sensor ("registration distance"), which hasn't changed from 35mm film to APS-C digital. And for wide angle lenses, that can be the more significant factor.

QuoteQuote:
also, isn't one of the main reasons to use pentax the lenses?
That's one reason, sure - but others are SR, weather sealing, ergonomics, etc.

Anyhow, like it or not, the introduction of good quality zooms and the availability of high ISO settings with decent quality, along with SR, have *GREATLY* diminished the market and indeed need for super-fast primes. Note, I did saying diminished, not eliminated. I am well aware there are still reasons to want faster primes. But the days when everyone needed one because zooms and high ISO speeds weren't practical are long gone. It's a niche product now.


Last edited by Marc Sabatella; 05-08-2009 at 08:52 PM.
05-08-2009, 10:28 AM   #32
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QuoteOriginally posted by Robert S Donovan Quote
The choices:

("and lo, did he post a multitude of images...")
See? We've got no good wide-angle choices for Pentax! It's like we're being starved or punished for our APS-Cness!

A friend of mine has a Nikon 8mm f/2.8, so yes it is possible to make very wide-angle glass that is fast. He paid $3000 USD for a used copy about 10 years ago, and it outweighs his camera body by 3:1, but is seriously sharp and contrasty.
Fisheye Nikkor 8mm f/2.8s lens
05-08-2009, 10:37 AM   #33
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QuoteOriginally posted by panoguy Quote
See? We've got no good wide-angle choices for Pentax! It's like we're being starved or punished for our APS-Cness!

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good is a VERY subjective thing. I see some amazing lenses on this list

but no doubt we loosing wideness with a crop sensor
05-08-2009, 12:29 PM   #34
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QuoteOriginally posted by AntiBad Quote
Yes, I suppose sigma does make something that sounds close, but the 20 and 24 are really kinda big and shouldn't a crop cam lens be a bit smaller than that... also the 30 1.4 (the one I had) had terrible edges... very mushy.
also, isn't one of the main reasons to use pentax the lenses?
if I wanted to use sigma lenses, I could use almost any other brand.... is it too much to ask for pentax optics and craftsmanship?

So how does the sigma 24 1.8 stack up against pentax's build and optical quality?
Sigma 20/24/28 f/1.8 lens cover 135 format ("full frame 35mm"). If Sigma ever made APS-C version of these lenses, they should be smaller.

05-08-2009, 12:49 PM   #35
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QuoteOriginally posted by panoguy Quote
See? We've got no good wide-angle choices for Pentax! It's like we're being starved or punished for our APS-Cness!

A friend of mine has a Nikon 8mm f/2.8, so yes it is possible to make very wide-angle glass that is fast. He paid $3000 USD for a used copy about 10 years ago, and it outweighs his camera body by 3:1, but is seriously sharp and contrasty.
Fisheye Nikkor 8mm f/2.8s lens
How many typical Pentax users are prepared to shell out 5000 USD for such a lens new (there must be bought some of them new, to get them into the secondhand market)? 95% of all lens threads in all Pentax related forums are typically starting with "I look for a good, but cheap... an affordable... under 300 USD" etc. So, simply, the Pentax users are a very price sensitive community and ther is simply a next to nothing market for such expensive lenses.

Ben

Last edited by Ben_Edict; 05-08-2009 at 02:26 PM.
05-08-2009, 02:14 PM   #36
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QuoteOriginally posted by redpigeons Quote
...but no doubt we loosing wideness with a crop sensor
I don't know about that. Full frame cameras demand a lot more from their lenses. The widest practical quality lenses only go down to about 14mm at f/2.8. A 10mm Sigma is right there at 15mm equiv. Sure it's not as fast, but I'm still not sure why anyone would want a truly fast ultra wide angle lens. By the time you get down to 20mm or less (equiv) you're not going to have much control over DoF anyway. Wide lenses are less prone to camera shake and high ISO and SR can easily make up the difference.

If I recall, the OP was looking for a really fast wide angle in the 24mm range. It seems there are several choices available from 3rd party brands. Granted they aren't in the sub-$300 range but show me a decent new lens that is.
05-08-2009, 06:21 PM   #37
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Re Robert S Donovan's comments:

QuoteQuote:
I'm still not sure why anyone would want a truly fast ultra wide angle lens. By the time you get down to 20mm or less (equiv) you're not going to have much control over DoF anyway.
My thought's precisely......

Best regards
Richard
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