Imaging resources review...

RaduA · 08-22-2009, 05:28 PM

I still think that the measurement type used by ColorFoto (and blende8 to slaughter the DA*55 btw

) is unrealistic in general usage where much smaller corrections are way more common. It's like pitting two family cars in a drag race. One will win but the results are totally irrelevant for the day to day usage.

Radu

Clem Nichols · 08-22-2009, 06:05 PM

Falk:

Thanks for the info. I was hoping you would come across this thread and provide some much needed enlightenment.

CN

falconeye · 08-23-2009, 07:06 AM

Originally posted by RaduA

I still think that the measurement type used by ColorFoto (and blende8 to slaughter the DA*55 btw

) is unrealistic in general usage where much smaller corrections are way more common.

It is reasonable to assume so.

Still, I disagree after having run my own tests.

E.g., look at the 5.4EV sound sample for Pentax K-7 in my blog (http://www.falklumo.com/downloads/pub/2009.06/afs/K7-03.mp3). You hear three focus operations: First from 35cm to ~1m, from then on staying at 1m.

The initial "long run" of the screw drive to 1m was actually faster (60ms) than the second confirmation long run (90ms). The third run didn't use a long run. By long run I mean a significant shift of focus. In all three cases, the long runs have been followed by two short runs (micro-adjustments) each. It is the total time of short runs which dominate the total focus time (560ms in the first, 430ms in the second case, delay from shutter half press to focus activity included).

Therefore, it doesn't matter too much if the lens was far from final focus in the beginning (for the K-7 and kit lens). It only saves 1 out of 3 or 4 focus operations total. They may be unnoticeable with the K-7 (20ms in 50ms succession) but the times are adding to the dominant term in shutter latency. I think this may be the price to pay for good focus accuracy.

It would be interesting to watch for microadjustment focus operations in AF.C mode. Maybe, it is has a lower shutter delay where initial focus position matters more.

Chwisch87 · 08-29-2009, 09:58 PM

Quote:

(shutter noise) It's quieter than any digital SLR I've used.

As Soon as the K-7 comes down in price it is MINE!

Quote:

Thoughtful touches like the IR remote sensor on the front and back of the camera make so much sense, it's a wonder others haven't adopted this feature; yet most competing semi-pro digital SLRs don't even have IR sensors built in, requiring an expensive adapter instead

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08-22-2009, 05:28 PM	#16
RaduA Guest	I still think that the measurement type used by ColorFoto (and blende8 to slaughter the DA*55 btw ) is unrealistic in general usage where much smaller corrections are way more common. It's like pitting two family cars in a drag race. One will win but the results are totally irrelevant for the day to day usage. Radu

08-22-2009, 06:05 PM	#17
Clem Nichols Veteran Member Join Date: Mar 2007 Location: Munfordville, Ky. Photos: Gallery Posts: 370	Falk: Thanks for the info. I was hoping you would come across this thread and provide some much needed enlightenment. CN

08-23-2009, 07:06 AM	#18
falconeye Veteran Member Join Date: Jan 2008 Location: Munich, Alps, Germany Photos: Gallery Posts: 6,871	Originally posted by RaduA I still think that the measurement type used by ColorFoto (and blende8 to slaughter the DA*55 btw ) is unrealistic in general usage where much smaller corrections are way more common. It is reasonable to assume so. Still, I disagree after having run my own tests. E.g., look at the 5.4EV sound sample for Pentax K-7 in my blog (http://www.falklumo.com/downloads/pub/2009.06/afs/K7-03.mp3). You hear three focus operations: First from 35cm to ~1m, from then on staying at 1m. The initial "long run" of the screw drive to 1m was actually faster (60ms) than the second confirmation long run (90ms). The third run didn't use a long run. By long run I mean a significant shift of focus. In all three cases, the long runs have been followed by two short runs (micro-adjustments) each. It is the total time of short runs which dominate the total focus time (560ms in the first, 430ms in the second case, delay from shutter half press to focus activity included). Therefore, it doesn't matter too much if the lens was far from final focus in the beginning (for the K-7 and kit lens). It only saves 1 out of 3 or 4 focus operations total. They may be unnoticeable with the K-7 (20ms in 50ms succession) but the times are adding to the dominant term in shutter latency. I think this may be the price to pay for good focus accuracy. It would be interesting to watch for microadjustment focus operations in AF.C mode. Maybe, it is has a lower shutter delay where initial focus position matters more.

08-29-2009, 09:58 PM	#19
Chwisch87 Veteran Member Join Date: Jan 2009 Location: Atlanta, GA Photos: Gallery Posts: 317	Quote: (shutter noise) It's quieter than any digital SLR I've used. As Soon as the K-7 comes down in price it is MINE! Quote: Thoughtful touches like the IR remote sensor on the front and back of the camera make so much sense, it's a wonder others haven't adopted this feature; yet most competing semi-pro digital SLRs don't even have IR sensors built in, requiring an expensive adapter instead