[EricT]

Eric, I posted something in your other thread. Maybe I missed this one of the threads but did you bring your k-r and lens both in for the service repair?

My frustrations are that I upgraded from a k-x to a k-r to get the improved functions and screen which I did; but only to receive inferior picture quality (indoor, low light conditions) that I only discovered after I downloaded pictures onto my computer and then I started reading the forum threads.

Through my own tested I found a really good work around with live-view; but want at least the same focusing performance as the k-x. I don't mean to be hard on Pentax but I'm disappointed after seeing all the Christmas pictures with bad front-focusing issues. Special shots that I missed and I would have captured with my wife's Canon S95!

I sent in just the kit lens, not the 50mm prime lens that I used for these tests. I know that they can individually adjust lenses, but I didn't want to be without all my lenses for several weeks.

[EricT]

I never said all K-r have this issue, although many K-r have the problem, as reported by the users. The bad thing is that pentax does not comment on this - this is just wrong! I shot with 6 dslr models for the last 3 years and I saw K-r had problem from my FIRST shot just by checking the picture on the camera screen! I do not understand you trying to explain to me and others how insignificant the FF on OUR K-Rs is. With my 21mm limited lens at 3.2 aperture it is about 20 centimeteres in artificial light!!! I sent it for repair and no freaking difference whatsoever! Plus, the e-dial was not working when the camera arrived! What the hell is this! This is just unacceptable!
I have the right to complain about a very serious problem with MY pentax product and it is out of place you telling me how significant it is. Plus, I do not need your advice what to do with my camera. Just, please, add something constructive to the discussion if you want to participate, because franckly, I am worried with this problem for the last month now, and comments like yours are tactless. You have a working AF - I am really glad for you, but I spent some money on K-r and limited lenses, whant to take pictures inside without flash and the pictures are bloody useless.

It is strange that the service did not make any difference. I would not give up on this, obviously several people are happy with their cameras (me too, after the service), so it should be fixable, even if it means getting a replacement.

[ursamajor]

Sorry you're having problems with your Pentax, but you're citing an on-line self-reporting sample of an unknown aggregate and implying it represents a 50% problem rate for the K-r universe. All this (or any such sample ) shows is a percentage of those that comment, not of those who own the product. It has no statistical validity and so is proof of nothing. As for what you say a Pentax rep said, I will take your word for it, but again, one rep offering an opinion is just opinion and that is neither factual nor verifiable.
Brian

OK, I realize that you have answers for all I said and therefore I give up. I gave examples, samples with incriminated issue, you instead, just comments. You didn't came with counterexamples. Show us how well your Kr focuses in artificial light. When you'll test your Kr and attach pictures I'll resume our dialogue. Until then, I reserve my right to ignore your comments. No offence. I'm full of fanboys.
alffastar, bullseye! Well said!

[GrinMode]

Ok.. did some tests, might as well add them here.

Firmware 1.01. Tripod, 18-55 DAL @ 55mm, IS0 800, f5.6, 100% crops

AWB Flourescent light


AWB Tungsten light


Tunsten WB Tungsten light


Live View AWB Tungsten light


Live View Tungsten WB Tungsten Light


My conclusions:
Setting WB to tungsten helps a bit. LV is not affected. Both of which concurs with other posters.

My course of action:
Use Tungsten white balance in tungsten light, or use live view. Not sending for 'repairs'.

As I posted in other threads, I believe this is a 'universal' issue, especially for lower end models. Ok, some might contend they don't experience it with other brand, I won't argue with that, since I don't have practical experience on that matter. Just basing on what I read in this and other sites.

For critical, static objects in tungsten light, the focus speed of live view (not very low light) is actually acceptable. It actually is more comfortable to work with than the OVF.

Anyway this just a personal opinion. My shooting habits really is not affected too much by this. I experienced this same issue with my DS 3 years after I've been using it .

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Last edited by GrinMode; 01-30-2011 at 06:48 AM. Reason: Forgot to add 100% crops

[FHPhotographer]

OK, I realize that you have answers for all I said and therefore I give up. I gave examples, samples with incriminated issue, you instead, just comments. You didn't came with counterexamples. Show us how well your Kr focuses in artificial light. When you'll test your Kr and attach pictures I'll resume our dialogue. Until then, I reserve my right to ignore your comments. No offence. I'm full of fanboys.
alffastar, bullseye! Well said!

Okay, that's a reasonable request, so here's a shot taken this morning using AF indoors under artificial light, EXIF included, focal point the middle bottle generally and the word "Fact" exactly centered...

What do you want me to do now, pretend I'm seeing a FF problem and agree with you and alffastar, or are you going to tell me this is the wrong test, under the next exact conditions to generate the result you want? Now will you please stop saying all K-r cameras have this problem and give it a rest?
Brian

[lavascript]

I would venture to say that there is a small amount of FF in that shot. The center bottle is indeed focused, but the rear bottle is certainly more OOF than the front. Since DOF is longer toward the rear, if the center bottle were the exact point of focus, the rear bottle should be a little sharper than the front.

Also, someone will probably scream "You can't do a focus test at f/5.6!!!" But not me.

That said, I am a fan of my K-r and I think the FF problems are overblown. I'll probably do my own test later this evening.

[ursamajor]

I did a test (see my own thread) and didn't noticed big FF issues. The problem was discovered in real life shootings, when I wanted to take some portrait-pictures to my daughter.



FH, I would have preffered a picture with the embedded Exif, just to see where the focus were made (see the picture bellow).



I agree with Iavascript's first comments.

PS: As you can see in my test from my thread, I sent my camera back for less FF than in your test (not to mention GrinMode's test), but in real life pictures and they (Pentax's employees) agreed there is a problem. But I'm glad you're happy and I will not bother you anymore. Be happy with your new FF camera! I would not be able to be so...

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Last edited by ursamajor; 01-30-2011 at 11:56 PM.

[FHPhotographer]

I would venture to say that there is a small amount of FF in that shot. The center bottle is indeed focused, but the rear bottle is certainly more OOF than the front. Since DOF is longer toward the rear, if the center bottle were the exact point of focus, the rear bottle should be a little sharper than the front.

Also, someone will probably scream "You can't do a focus test at f/5.6!!!" But not me.

That said, I am a fan of my K-r and I think the FF problems are overblown. I'll probably do my own test later this evening.

lava, ursa et al
My bad; the original image was a flawed test. Luckily I had left everything where it was, and when I looked at it again I saw that the rear bottle was a bit further away from the focus point than the front bottle. What you saw wasn't FF, but just normal DOF. Here's the redo with the bottles more carefully placed so the front and rear bottle are the same distance from the center focal point (and same settings), and unless my eyes are failing me in my dotage, I see no FF/BF.
Brian

[ursamajor]

FH, no offence, but I didn't manage to see where you intended to do the focus. The AF point can't be seen/checked. See the photo bellow.

I don't want to show you how bad is your (or anybody's) Kr and I hope you don't want to show me how good is it. The test should be fair. To be honest, the photo looks fine, if the AF was intended on the middle. In my tests I've got SOME pictures with corect AF. But NOT A SINGLE ONE when I take portraits pictures to my daughter, and I assure you it wasn't user error.

[lavascript]

It's going to take me some time to compile the "proof" photos, but I put together what I believe is a very thorough AF test. Actually, I may be able to get my hands on a K-x this week to do even more comparison testing.

But my findings are basically that my K-r has severe front focus in tungsten light, which focus adjust -10 doesn't even begin to touch. Seems to me that it would need an adjustment of -50. One of my problems is that the focus issue only seems to be present in true tungsten light. I have tungsten-balanced CFLs in many of my fixtures, and the focus is much more accurate there. But my testing was done in the bathroom, with tungsten vanity lights, and the den, with tungsten candelabra bulbs, and the results were frankly startling. And oddly, while setting a tungsten WB seemed to help a little, the colors were very green.

[FHPhotographer]

ursa, The focus point was the same as the first image, in the middle on the word "Facts." I really have no issue with your repeated criticism of the K-r as long as you and others don't keep insisting that all K-r cameras have this AF problem. They demonstrably do not,
Brian

[ursamajor]

OK, be happy with your camera, but I preffer to believe the guy from Pentax. The difference between me and you and some other owner is that I'm saying that there is a problem with FF in artificial light (more in tungsten) and some other people says that THEY ITSELVES CAN CAUSE the FF issue. For me is the same.
Just a rhetorical question: if Pentax will publish a firmware to solve the FF issued, you'll upgrade yours? Because, I suppose/expect that the firmware will disadjust the AF system from the "good" cameras...

PS: Doing the test with bottles, batteries (see my thread) or other objects aligned like in your picture, I had the impression that I have a good copy of a Kr. When I did the test in real life shooting, on my daughter and on focus diagrams, I was disappointed.

[lavascript]

ursa, I think one of the major reasons you're seeing real-world FF and not in tests is that the problem increases with subject distance, at least as far as I can tell. You're shooting test subjects very close up, but your real-world shots are of people who are further away.

[cloud016]

testing af should with certain distance, not the close up distance!
AF microadjustment for the 1Ds mark III, 1D Mk3, 5D Mk2, 7D

Note - Camera-to-subject distance should ideally be no less than 50 times the focal length of the lens. For a 50mm lens, that would be at least 2.5 meters (25m for a 500mm)

FH, could you take some 'real life' shots like portrait or more distinct subject? no offence, but your sample was took at 40mm/f5.6 on a complex texture and maybe at very close range.
that`s not easy to distinguish.


ursamajor, I am worried about the 'software solution', maybe they(Pentax) just expand the af adjustmant range.

[ursamajor]

Yes, you both have right.

cloud016, if they only expand the AF adjustement, how we'll shoot in daylight after an AF adjustement for tungsten? We'll need to use the adjustement menu every time we'll change the type of light. Maybe they'll be able to hide in the firmware a permanent adjustement setting only for tungsten. It is my hope.