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05-11-2009, 12:41 PM   #16
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No its not that bad. The bad thing it doesn't go away that easy when stopping down, most because it isn't simple softness but a mix of distortion, curved focal plane, vignetting and CA's. Usually lenses are soft wide open and get ok after few stops(F4..F7 reaches sweet spot). At 10Mpix, you don't get completely away from CA's at moderate contrast even at F9.

Using F1.4 lens in such a way is just an irrational expense. But still im after the punchy contrast and colour sharpness you get with a quality fixed focal lens. Sigma has it, but with additional price of F1.4.

Here is a sample @F9. Its ok even when viewing on 19", CA's are barely noticeable, (if you search for them), visible in prints (but if im about to print anything its good enough reason to correct anything i can - distortions, CA's, exposure, etc), sharpness is acceptable.

P.S. And the 28 was 105$ with shipping.

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Last edited by ytterbium; 05-11-2009 at 12:55 PM.
05-11-2009, 12:55 PM   #17
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QuoteOriginally posted by ytterbium Quote
No its not that bad. The bad thing it doesn't go away that easy when stopping down, most because it isn't simple softness but a mix of distortion, curved focal plane, vignetting and CA's. Usually lenses are soft wide open and get ok after few stops(F4..F7 reaches sweet spot). At 10Mpix, you don't get completely away from CA's at moderate contrast even at F9.

Using F1.4 lens in such a way is just an irrational expense. But still im after the punchy contrast and colour sharpness you get with a quality fixed focal lens. Sigma has it, but with additional price of F1.4.

Here is a sample @F9. Its ok even when viewing on 19", CA's are barely noticeable, (if you search for them), visible in prints (but if im about to print anything its good enough reason to correct anything i can - distortions, CA's, exposure, etc), sharpness is acceptable.
Thanks for the info. What a strange beast. At least with f/1.4 you get a brighter viewfinder.
05-12-2009, 12:26 AM   #18
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Why dont you consider sigma ex 50mm F1,4?? Itīs very good and cheaper than 70mm/2,4..
i also wrote review of it to lens review page.
05-12-2009, 12:57 PM   #19
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The DA70 and Sigma 50 both go for around $450-550, but to the extent there is a difference, the DA70 is usually cheaper when I've checked. They are also very different focal lengths. I like 70 much better than 50 personally. And of course, there is an enormous difference in size - they really have very little in common.

05-12-2009, 11:03 PM   #20
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QuoteOriginally posted by pexi85 Quote
Why dont you consider sigma ex 50mm F1,4?? Itīs very good and cheaper than 70mm/2,4..
i also wrote review of it to lens review page.
Well.. as told in my previous posts, i already bought Ltd70, used ~300$. When New goes for ~ 670$ where i am, and the Sigma you mentioned for 570$.
As well as the Da is A Limited (with all the neat consequences), is much smaller and lighter.
05-13-2009, 09:57 AM   #21
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QuoteOriginally posted by pexi85 Quote
Why dont you consider sigma ex 50mm F1,4?? Itīs very good and cheaper than 70mm/2,4..
i also wrote review of it to lens review page.
You wrote that AF was fast. How fast is it compared to, say, the kit lens (which is pretty fast)? You also have DA 35 f/2.8 and DA 55-300, both of which are very slow, AF-wise (EDIT: or perhaps not, in case of DA 35).

EDIT: Actually, here's a video: http://www.youtube.com/watch?v=89OOvwha2JE

Last edited by asdf; 05-13-2009 at 10:30 AM.
05-13-2009, 10:15 AM   #22
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I find the DA35 pretty darn quick.

I have both the DA40 and DA35 and in good light, I don't find any noticeable difference in AF speed.
05-13-2009, 10:29 AM   #23
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QuoteOriginally posted by soccerjoe5 Quote
I find the DA35 pretty darn quick.

I have both the DA40 and DA35 and in good light, I don't find any noticeable difference in AF speed.
Thanks for the info about DA 35. Out of the two (DA 35 and 55-300), I only used 55-300 and its AF seemed very slow.

05-13-2009, 12:22 PM   #24
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Since i didnt choose Pentax as slr system for AF (my P&S had as fast AF as my k200) im happy as long as it works and is correct.

Back to the lenses. Do you think Sigma is worth keeping if i dont use it much at F1.4 (More often 2 and up) and M28/2.8 should be on its way.

What good AF alternatives are there whose price i could cover more than 200% if i sold 30/1.4 and M28/2.8?

Last edited by ytterbium; 05-13-2009 at 12:39 PM.
05-13-2009, 12:38 PM   #25
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The DA35 focuses fine in normal light. If I use it in a situation where it hunts, it's awfully slow. Being a macro lens, the focus throw is longer and that slows it down considerably. Other than that, the focus speed is fine.
05-21-2009, 01:56 PM   #26
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Ill buy your sigma off of you if you need to sell it, i prefer a more wide angle prime.

Thanks!
05-21-2009, 03:34 PM   #27
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The Sigma 30 is not as bad as most say... It is certainly not as good as the DA* 55 but it is a good low light lens.



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