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07-02-2012, 02:29 PM   #16
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QuoteOriginally posted by L33tGreg Quote
What AF mode are you using (AF-S, AF-C)? ?
I was going to ask the exact same question. If in AF-C and trying to use centre confirm , then recompose, the camera will refocus on whatever is in the centre again.

Opps sorry, just saw your repy just before my post.

07-02-2012, 02:35 PM   #17
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cmohr: np

QuoteOriginally posted by Anvh Quote
I don't know if you can retry the shot?
Are you referring to the window frame shots? Will have to wait till tomorrow. It's too dark now, but I normally use basically same method as you are suggesting. I'll give it a go anyways.
07-02-2012, 02:39 PM - 1 Like   #18
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I think the problem you are having has to do with focus-recomposing rather than camera/lens focus issues. If you focus on the light or a sign in the center and then pivot the camera so that the object is now near the edge of the frame and you are using a wide-aperture, you're going to have focus problems because you are moving the plane of focus to behind the object you actually focused on.
07-02-2012, 03:10 PM   #19
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I recompose all the time. I rarely use anything else than the center spot. If I do it's because I do not have time to recompose (typically events with movements involved - a wedding for example). Marginal focus issues, sure - but not as severe as the ones in these pics - also, I recomposed in the beginning, but later figured I would be doing myself a favor by keeping whatever I wanted the focus to be on, in the dead center as that wouldn't require me to remember what I was focusing at - I find stuff like that rather easy to forget.

Anvh: I couldn't help myself and took some pics with the window again: 2012.07.02 - Zafar Iqbal's Photos | SmugMug

First three: Had the black portion centered.
Last 3: Had the white portion centered

I manually focused in and then auto focused. I forgot to do this on pic 5 though and the fact that pic 5 is the sharpest of them all is to my belief a coincidence. I'm surprised by the results. Thought I would nail it as I had much success in the shop - the artificial light is different though and that's possibly why.


Last edited by Zafar Iqbal; 10-29-2013 at 02:03 PM.
07-02-2012, 03:54 PM   #20
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Was talking about the ones with the street signs or lamp, the window post is a bit of a strange target.
If you want to check focus there is a way actually, while it's not 100% correct it would show you if it's good enough or not.

AF microadjustment for the 1Ds mark III, 1D Mk3, 5D Mk2, 7D

Not perfect but at least it's more controllable.
07-02-2012, 04:39 PM   #21
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I almost always use AF select on my K5, the auto mode could never find what i wanted to focus on. I don't really have any problems with the center focus setting on my K5. I have to admit though that the continous AF on my old 20d is a bit better than on this fairly new K5. I did read something years ago on the Luminous Landscape about how focus recomposing is very unreliable, but i don't remember why.
07-02-2012, 04:43 PM   #22
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I glimpsed through it quickly (it's past bedtime here :P - will read it closer tomorrow) and did the moire test with my 70mm Limited, which is the lens I've so far used the most with both K-5 and K-r.

It's spot on - I can't hear or see the focus ring turn even the slightest. Looking at the VF also doesn't indicate I need Micro Adjustment.

None of my lenses were ever calibrated to my K-x (or is it the other way around)? Not sure how it is from camera to camera, but my thinking is, if they worked fine with K-x they should work fine with any other Pentax camera.

I've done "I'm bored, let me photograph my monitor" lots of times, and caught that moire thingy that occurs plenty of times. Never had issues that lead me to think some of my lenses mgiht be off - but that's with K-x, in case there *is* a difference from camera to camera.

A thing I noticed just 30 mins ago: the light illuminating from my monitor enables the K-r to focus properly on items that are illuminated sufficiently enough by the monitor. If I however turn the other way around and aim at something that is primarily illuminated by my energy saving bulb (orange light), the focus can be off by as much as 15 cm with a shooting distance @ approx 1-2 meters. when I did the moire test, the cam was about 1.25m from the monitor - enough to fill the VF with the square from top to bottom.

I'll shoot some street lights tomorrow.

Williunck: I understand why recomposing can be a bad thing, but it's IMO very irrelevant in my case. The It's impossible for the focus to shift that much as some of my photos show. I've to this day never used auto point thingy mode. Maybe just to try it out fr a minute but that's it. I either select my point (center point more than often) or focus manually.
07-02-2012, 04:46 PM   #23
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I've been shooting with my NEX more lately, and I can easily nail thin DOF shots with MF. I shot the K-5 this weekend and it does miss a lot in harsh light. My keeper rate was way lower than with the NEX. You can't really adjust for it because the value is different based on conditions.

07-02-2012, 04:50 PM   #24
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Ah, "good" to hear from someone who seems to be experiencing same issue. "can't really adjust for it because the value is different based on conditions" - exactly what I've been noticing as well. My K-5 shifted the focus as the light level went lower as mentioned earlier, and as I *just* wrote, seems very clear K-r is affected by not only light level, but light type as well (maybe they are related but whatever.. its not working whatever it is!).
07-02-2012, 04:58 PM   #25
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It will be interesting to see a comparison with the K30. It's af is suposed to be far better.

Now i am curious about the K5 AF in different sources of light...
07-02-2012, 05:02 PM   #26
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QuoteOriginally posted by Zafar Iqbal Quote
I glimpsed through it quickly (it's past bedtime here :P - will read it closer tomorrow) and did the moire test with my 70mm Limited, which is the lens I've so far used the most with both K-5 and K-r.

It's spot on - I can't hear or see the focus ring turn even the slightest. Looking at the VF also doesn't indicate I need Micro Adjustment.

None of my lenses were ever calibrated to my K-x (or is it the other way around)? Not sure how it is from camera to camera, but my thinking is, if they worked fine with K-x they should work fine with any other Pentax camera.

I've done "I'm bored, let me photograph my monitor" lots of times, and caught that moire thingy that occurs plenty of times. Never had issues that lead me to think some of my lenses mgiht be off - but that's with K-x, in case there *is* a difference from camera to camera.

A thing I noticed just 30 mins ago: the light illuminating from my monitor enables the K-r to focus properly on items that are illuminated sufficiently enough by the monitor. If I however turn the other way around and aim at something that is primarily illuminated by my energy saving bulb (orange light), the focus can be off by as much as 15 cm with a shooting distance @ approx 1-2 meters. when I did the moire test, the cam was about 1.25m from the monitor - enough to fill the VF with the square from top to bottom.

I'll shoot some street lights tomorrow.

Williunck: I understand why recomposing can be a bad thing, but it's IMO very irrelevant in my case. The It's impossible for the focus to shift that much as some of my photos show. I've to this day never used auto point thingy mode. Maybe just to try it out fr a minute but that's it. I either select my point (center point more than often) or focus manually.
Very strange...
Anyway there is a tolerance level in the lens and in the camera, so for example with the Kx and DA70 you could have -2 for the camera and +2 for the lens and you will get perfect focus but the K5 could be -2 and then it's -4 off. What i'm saying is if a lens focus perfectly on camera doesnt mean it also focus good on another camera.

But the test shows at leas the focus is okay with your camera so we can flick that one of the list for daylight shooting, it's most likely a setting or user error in that case.

Now with low light the Kr and K5 are known to back focus, pentax have tried to patch it but its a hardware problem as far as i know so not easily fixed by a simple patch sadly but during daylight you shouldnt have this problem. btw this problem is know since the K5 was released you know so no something new...
07-02-2012, 05:04 PM   #27
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QuoteOriginally posted by Williunck Quote
It will be interesting to see a comparison with the K30. It's af is suposed to be far better.

Now i am curious about the K5 AF in different sources of light...
far better?
I have only heard the words "improved" but what that precisely means
07-02-2012, 05:11 PM   #28
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Just confirming when you are doing the centre focus/re-compose that you are keeping the shutter button half depressed so the focus stays locked where you focused during the recomposition??
Maybe also a faulty shutter release button? Try to set the camera to "not" focus with half press of the shutter and only with the AF button on the back of the camera, and try the centre focus/recompose with that setup..You only press the AF button untill you get AF confirmation, then let go, recompose and see if your results are better.

Also as people say, centre focus then recompose can have its drawbacks, especially with lenses with a thin DoF, the focus plain is always perfectly parrellel to your sensor, if you have the camera pointing downwards and at an angle to get focus on your subject, then bring the camera up level and pointing in a diferent direction, the pocused plain can and does move away from what you originally focused on, a small movement of 10-20 degrees can make that focus plain move in distances of feet out where you are recomposing. Imagine a gaint triangle reaching out from your camera, with the end of the triangle being what you locked focus on, a small movement of your camera will move that triangle quite a distance, you won't see a huge difference with wide angle lenses as they have a large DoF, but you are using a 70mm telephoto completely open, to take a picture of a large area, the focus plain is going to move dramatically from where you focused originally.
07-02-2012, 05:14 PM   #29
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QuoteOriginally posted by Anvh Quote
far better?
I have only heard the words "improved" but what that precisely means
I thought i read "superior" somewhere, but dpreview said this "The K-30 features the new state-of-the-art SAFOX IXi+ AF sensor module, which assures responsive, high-precision autofocus operation" which if I imagine "high-precision" and "state of the art" It would translate to "far better" in my mind.
07-02-2012, 05:22 PM   #30
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state of the art simply means it's new and AF systems are accurate up to a micrometer, dont know if you can call that high precision or if we would even notice more precise autofocus?
Also it says high-precision, nothing about that it is improved.

The lowlight error with the K5 and Kr is something else though, that was a design fault i think so that should be out of the new models!!!

I've the K5 and the AF is fine during day light, no problems at all but better tracking would be nice but that's it beside the low light problem.
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