How come Pentax limited lenses didnt extend up to 100mm

Recercare · 04-05-2010, 12:34 PM

Originally posted by rustynail925

I though its the same with AF lenses switch to MF.
Recercare - Isnt the AF accurate ? how come you get more out of focus pics in AF?

I think it's because I often shoot in low light environments. My k10d locks focus quite fast but the focus is usually a bit off, sometimes it's back focus and at other times it's front focus. When overriding the AF of my DA 40 I find the focus ring quite uncomfortable to use. Like Marc said, it's hard to fine tune because even a very small twist changes focus dramatically.

When using ext. flash or shooting in decent light I get good results using AF on the K10d + DA Ltd's.

Kind regards
.lars

rustynail925 · 04-05-2010, 01:20 PM

Thanks for all the explanation...

**Douglas_of_Sweden** · 04-05-2010, 02:16 PM

What Pentax should do?

Tweak the M85/2 into a DA 90 ltd. If they decrease the speed to f2.4 its fine with me, as long as they keep the IQ, even though f2 would be nice. This will give us a fairly small and fast short tele with a image angle that on APS-C would correspond to 135mm in the 35mm film format, a classical focal length. It would also place the lens right in the middle of the 77mm ltd and the DFA100 macro.

Make a DA 135 ltd version of the M135/3.5. That would correspond to an amazingly small 200mm lens in the 35mm film format.

DA 15, 21, 35macro, 40, 70, 90 and 135 ltds would be the final and perfect DA limited serie where all but the 40mm would give us in APS-C close to classical focal lengths from the 35mm format: approximately 22.5mm (right between the classical 21 and 24mm), 31mm (a compromise between the 28 and 35mm), 52.5 mm (right in between 50 and 55mm), odd 60mm*, 105mm, 135mm and 200mm. Only missing a DA 56mm ltd for a 85mm proxy, but that wont happen due to the DA*55.

*The DA40, being built on the original M40 pancake with modifications of one or two lens elements, is really a film format focal length.

Pentaxor · 04-05-2010, 03:31 PM

Originally posted by Recercare

When using ext. flash or shooting in decent light I get good results using AF on the K10d + DA Ltd's.

Kind regards
.lars

they keep things in focus and optimal quality.

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04-05-2010, 12:34 PM	#16
Recercare Veteran Member Join Date: Oct 2008 Location: Sweden Posts: 359	Originally posted by rustynail925 I though its the same with AF lenses switch to MF. Recercare - Isnt the AF accurate ? how come you get more out of focus pics in AF? I think it's because I often shoot in low light environments. My k10d locks focus quite fast but the focus is usually a bit off, sometimes it's back focus and at other times it's front focus. When overriding the AF of my DA 40 I find the focus ring quite uncomfortable to use. Like Marc said, it's hard to fine tune because even a very small twist changes focus dramatically. When using ext. flash or shooting in decent light I get good results using AF on the K10d + DA Ltd's. Kind regards .lars

04-05-2010, 01:20 PM	#17
rustynail925 Veteran Member Join Date: Aug 2009 Location: Philippines Photos: Gallery Posts: 1,551 Original Poster	Thanks for all the explanation...

04-05-2010, 02:16 PM	#18
Douglas_of_Sweden Site Supporter Join Date: Apr 2008 Location: Stockholm Photos: Gallery Posts: 3,374	What Pentax should do? Tweak the M85/2 into a DA 90 ltd. If they decrease the speed to f2.4 its fine with me, as long as they keep the IQ, even though f2 would be nice. This will give us a fairly small and fast short tele with a image angle that on APS-C would correspond to 135mm in the 35mm film format, a classical focal length. It would also place the lens right in the middle of the 77mm ltd and the DFA100 macro. Make a DA 135 ltd version of the M135/3.5. That would correspond to an amazingly small 200mm lens in the 35mm film format. DA 15, 21, 35macro, 40, 70, 90 and 135 ltds would be the final and perfect DA limited serie where all but the 40mm would give us in APS-C close to classical focal lengths from the 35mm format: approximately 22.5mm (right between the classical 21 and 24mm), 31mm (a compromise between the 28 and 35mm), 52.5 mm (right in between 50 and 55mm), odd 60mm, 105mm, 135mm and 200mm. Only missing a DA 56mm ltd for a 85mm proxy, but that wont happen due to the DA55. *The DA40, being built on the original M40 pancake with modifications of one or two lens elements, is really a film format focal length.

04-05-2010, 03:31 PM	#19
Pentaxor Veteran Member Join Date: May 2009 Location: Vancouver, B.C. Photos: Gallery Posts: 6,513	Originally posted by Recercare When using ext. flash or shooting in decent light I get good results using AF on the K10d + DA Ltd's. Kind regards .lars they keep things in focus and optimal quality.