[Christine Tham]

Well I'm not convinced, it's an advanced camera and many doesn't understand how the AF work....

LOL

Since some claim I am a confirmed authority on this, can I be the first to say ...

It's obviously "user error" on Falk's part ...

[markus9494]

Who thinks it would be an appropriate gesture on Pentax's' part to reimburse Falk for his time and effort? Oh well, we can only dream. Perhaps we, as forum users can all kick in a few bucks to convince him to test the Kr as well? Just a thought. I am pretty sure most people would rather invest a few bucks in such a study rather than buy a camera for its low light capabilities only to find it lacking.

[RonHendriks1966]

Great work. I will look in it this afternoon, but it is an amazing job!

[Matso]

Wow. Thank you for this hard work. I'm not scientifically minded in the least, so don't understand a lot (ok, almost all) of your essay, but I really appreciate the lengths you've gone to explain the issue to Pentax and I really hope this contributes to a solution (in my case, for the K-r).

[the swede]

Im really afraid they'll ditch us (past issues), but i really hope, and will not abandon this yet!

Please Pentax! Fix this!

[Michaelina2]

....Possible error in the summary:

2. Should probably read "in front of the sensor plane"?

Hmmmmm...

...Hmmm, perhaps we really do need a petition from this forum from all of us to ask Pentax...

Instead, assuming the OP is working independently and not a troll in sheep's clothing, it might be more appropriate for each reader who feels the report means something to contribute some money so he can keep his "Errors and Omissions" insurance policy current.

I'm NOT a lawyer, but it seems reasonable, if Hoya can find an error in the OP's methodology and can show that error produced damages (thank you all who have publicly declared they will not buy due to the OP's study results), he could be held liable for multiples of the damages.

BTW: Does anyone wonder why someone would want to insert themselves into a public discussion in such a conclusive way using an N=1? Based on other experiences, surely the OP is aware of the time and energy black-hole he's creating for himself, plus the self-inflicted headaches to follow?

Again, just curious... M

[alffastar]

Hmmmmm...



Instead, assuming the OP is working independently and not a troll in sheep's clothing, it might be more appropriate for each reader who feels the report means something to contribute some money so he can keep his "Errors and Omissions" insurance policy current.

I'm NOT a lawyer, but it seems reasonable, if Hoya can find an error in the OP's methodology and can show that error produced damages (thank you all who have publicly declared they will not buy due to the OP's study results), he could be held liable for multiples of the damages.

BTW: Does anyone wonder why someone would want to insert themselves into a public discussion in such a conclusive way using an N=1? Based on other experiences, surely the OP is aware of the time and energy black-hole he's creating for himself, plus the self-inflicted headaches to follow?

Again, just curious... M

Now this is one of the most terrible posts I have seen in a photo forum . Do not even want to comment it...

[alffastar]

Falconeye, I am an user of pentax K-r. I saw the problem of FF from the very first shot! Unfortunately, I bought also 15mm, 21mm, 40mm and 70mm limited lenses. At least it will be unfortunate if Pentax will not fix the FF of K-r and K-5 as I will have to sell my pentax system.
I find it absolutely unacceptable that an user will post such extensive info on the problem BEFORE Pentax. This is just wrong as Pentax should have addressed this issue themselves a long, long time ago in this very galaxy!!! I also think Pentax should know all that is in the OP report, but I find the report invaluable for the pentax community! Thank you for this as a pentax user!

[opiedog]

this k5 low-light AF reminds me of my K10d's AF. although it wasn't a consistent issue, the AF would miss for no reason at all. Sometimes 2 shots one after the other (refocus after each shot0 would produce one in focus, one OOF.

since the AF module (SAFOX) has not really changed for ages (except for the addition of the color sensor), i'm inclined to think that it's a limitation of the AF module itself, IOW, hardware.

yes, some software work-arounds are indeed possible, but to get a real fix would mean updating the AF sensor itself which will have to wait for the next round of bodies. I was hoping that this round of bodies would use a new sensor, but it seems like it's the same SAFOX.

[thibs]

The fact the thing is called SAFOX doesn't mean nothing changed since SFX.

Canon lenses are called EOS, does that mean they did not change since EOS bore (not talking about the glass itself) ?

[the swede]

If Pentax had put a brand new SAFOX in there, they would be more than happy to announce that, even before the lauch of the K-5. They do it with everything new they come up with, so they would have done it.

only my very humble opinion though

[audiobomber]

I shoot with a K20D so I know exactly what you're talking about -- but I think it's a color-temperature issue rather than a light-level issue. That's why the K-7 introduced the color sensor as part of the AF sensor module, and I believe many people have reported that the K-7 goes a LONG way toward fixing that problem.

But this is apparently a new problem in the K-5.

I agree with Quicksand. I tested my K20D and K100DS and found they FF in tungsten light and focussed properly in daylight, no matter if it was dim or bright. I didn't bother to test my K-x when I got it, but I know it does the same thing.

[opiedog]

The fact the thing is called SAFOX doesn't mean nothing changed since SFX.

Canon lenses are called EOS, does that mean they did not change since EOS bore (not talking about the glass itself) ?

unless pentax marketing is sleeping, a truly NEW AF module should be advertised to the high heavens. (toot your horn, pentax)

but looking at the last 6 years of pentax bodies, the only time they really advertised their AF was when SAFOX got a +, and yes for the k5 and kr, some updates to the AF module's lens. how much of an update is that?

if it's truly a NEW AF module, new electronics, etc, TOOT it pentax!

[falconeye]

I don't think this issue is unique to the K-5, so perhaps we can rule out specific changes in the K-5 as the true cause of this problem?
[...]
Lastly, I have not done an exhaustive test of my lenses, but I do believe the problem varies depending on lens, but I don't necessarily believe it varies according to your hypothesis.

Yes, the hypothesis needs more data. There seems to be some lens dependency indeed. Which is strange enough in itself, actually. My hypothesis is compatible with the limited data I had. If anybody knows about a lens pair where the slower one jumps later (so to speak, meaning, doesn't have the focus shift while the faster already does), then this would be a very valuable contribution rejecting the max. aperture hypothesis. After all, it may be a false path...

Maybe, the AF assist light behaviour (single or multiple engagements) is lens dependent rather than camera dependent. Could be another important clue.

Moreover, I think that maybe the K10D struggles in low light as well. Unfortunately, I could not repeat the test for other cameras or brands. Nevertheless, I would be surprised to learn that focus for the K10D jumps in such a binary way when the light is dimmed.

@Falk
Does the test come in at the latest firmware version? The old one i think is much better 1.01.

It is 1.01.00.05 (1.01). I heard that the 1.02 doesn't improve and so I didn't want to upgrade in the middle of my tests.

It's obviously "user error" on Falk's part ...

I am sure (from experience), I can do user errors as much as anybody else. So, please watch out for the errors I make :ugh:

Does anyone wonder why someone would want to insert themselves into a public discussion in such a conclusive way

Yes, and it has been subject of philosophical debates.

To make a long story short: If all humans were like you and unlike me, it can be shown we all would still live in caves. Like all other animals actually. To spread sperm (or raise children) isn't all you can do for your species, assuming a minimal degree of organization. I think that's all I say about this. But good literature about the topic exists. Thanks for your question.

[dcmsox2004]

your efforts are greatly appreciated falk, your technical acumen is nonpareil..... why pentax hoya didn't thoroughly beta test the k-5 (and k-r) is a puzzlement...... regards and many thanks, dave m