[selar]

The Samsung GX10 has MTF line as well - which I have used almost exclusively since I got it, as that was one of the reasons for upgrading from K100D. The manual simply states "MTF priority program is an Automatic Exposure Program that selects the best aperture settings for the attached lens." It does not make the distinction that it only works with FA, FAJ etc. Does that mean its more compatible than K10D with third party lenses?

[mattdm]

The Samsung GX10 has MTF line as well - which I have used almost exclusively since I got it, as that was one of the reasons for upgrading from K100D. The manual simply states "MTF priority program is an Automatic Exposure Program that selects the best aperture settings for the attached lens." It does not make the distinction that it only works with FA, FAJ etc. Does that mean its more compatible than K10D with third party lenses?

I think it just means their manual is even less helpful than Pentax's.

[m8o]

The plot thickens...

[Geekybiker]

to test this further, wouldn't you be able to point the camera at something that's rather bright to give a aperture like f16 or f22 (if lens supports) then the MTF program should try to open that up a bit (smaller f number) and increase the shutter speed to match to get nearer the lenses sweet spot.

I think it would still do this. Like I said you can make some basic assumptions about lens performance in general and the camera can use a basic algorithm to stay in the normal sweet spot of most lenses. I think where you'd see a big difference between the MTF chipped lenes and non-MTF chipped 3rd party lenses is if the lens has a fairly abnormal profile. And even then you might not really notice without getting out the resolution charts and doing an objective analysis.

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Last edited by Geekybiker; 02-26-2008 at 05:17 PM.

[HGMonaro]

And even then you might not really notice without getting out the resolution charts and doing a objective analysis.

yep... as someone mentioned above, in the real world, you'd use an aperture that suits the picture you want rather than the sharpest possible which may not be appropiate (eg a near/far landscape is going to need an appropiate aperature)

Nige.

[TedW]

Below is a link to test data (resolution) of older K, M and A and few FA lenses. If you scan the data you can see a pattern of top resolution at f8 for almost all of these early lens. You also can see one of the reasons why the K 28mm 3.5 is my favorite landscape lens, especially for stitching multiple photos together. The data on the K 55 1.8/2.0 is also great but I like colors and auto aperture of the A 50mm 1.7.

Some of those old lens still produce outstanding results as many of us know.

http://www.takinami.com/yoshihiko/photo/lens_test/pentax_normal.html

[microlight]

MTF selects the optimal aperture for lens performance (pleased to hear that Pentax assessed this individually on my HD-DA20-40 Limited!). This of course only works in program mode, and in the cases where I want to stop down (or stop up!) then I just use the rear thumb-wheel on my K-5 to shift into hyper-Av. This is where the hyper modes and the green button make the Pentaxes so flexible.

[Na Horuk]

This thread is from 2007. Good that it was finally answered, though.
And the MTF P mode is where the camera chooses the aperture for the best resolution of the specific lens you have mounted chosen (aperture affects optical quality). The camera knows this because Pentax engineers put this data into the lens id.