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10-20-2009, 09:07 PM   #31
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,

Cross posted, but Gordon also now has called it:

QuoteQuote:
4) This is the very best high ISO performance of any camera Pentax has produced to
date, matching or exceeding any of the Nikon models including the D300 and D300s.
This was never really a problem with even the K20D and K-7 in that they likely
match most competitors high ISO performance with just a little touch of Noise
Reduction (NR), but this K-x appears to match or exceed other competitors without
any NR or with very very little, just as those competitors may apply.

link



.

10-20-2009, 09:12 PM   #32
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I think we can all agree both the lens and body usually are not 100% spot on perfect - such is a fact of life.

I think none of us know what specs lenses and bodies are made to. I hope that it is a tight spec such that at f/2.8 or f/2 or maybe even f/1.4 that the most barely in spec body and barely in spec lens in opposite directions would not be very noticible in most cases, but none of us can know.

I think to many non-perfectionists non-razor-thin DoF shooters (discounting macro where you would review or manual focus anyway), it will be ok. Personally I'd love this feature and would go crazy with a focus chart with all of my lenses, but I love K-x's price more and its features more than the K20D. If a affordable K200D successor comes out with the K-x + weathersealing + AF adjustment - I'd buy it, but who wouldn't? I am getting a 1.35x mangifier and maybe even a diagonal split-image focus screen and shouldn't worry about it. But then again, maybe my shim is a mm too thick or too thin... well, back to square 1.

Googling around I found this:

QuoteQuote:
According to Pentax, all newer DA Series of lenses are tuned at the factory for proper focus with all Pentax DSLR bodies. However, the older K-mount lenses may produce back or front focused images.
Yes a quote of a quote, but maybe the DA40 was out of spec and you should've sent it back.
10-20-2009, 09:32 PM   #33
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QuoteOriginally posted by schmik Quote
My testing (i believe) is solid.
OK, then, your camera is defective and you should simply return it.

I can understand why one might be hesitant to return a defective camera, but the point is, like I said, it's blowing things way out of proportion to say that without AF adjustment you're doomed to out of focus pictures at f/2.8. that's true *only* if you get one of the small percentage of defective cameras *and* you're unwilling to have your defective camera replaced.

So I'm certainly not opposed to having the adjustment feature, and while I personally would rather return a defective camera than use a hack like that to try to cover up the defect, I can understand that some might prefer the cover-up over having the problem actually fixed. So I'm not trying to talking you into buying a camera without the ability to perform that coverup.

I'm just trying to make sure prospective buyers don't get the wrong idea from your comments. They should not be fooled into believing that not having AF adjustment means they can't get in focus pictures at f/2.8. That's just not true. They'll only have problems if happen to receive a defective camera, and even if that happens, they can return the camera for a properly working one. There is no danger of being stuck with a camera that can't focus at f/2.8. That's not a problem anyone should have to worry about any more than any other defect that can potentially occur and for which you can *also* get it repeaired/replaced under warranty. Defects happen in all models, but that's what warranties are for.

QuoteQuote:
As i've said many times (in other posts) adding AF adjustment in camera is an admission that things are not perfect out of the box.
Sure, but again, the extent to which things are not perfect is not, in general, such that you can't get an acceptable percentage of in focus shots at f/2.8 with proper technique. If your gear is not doing this, it is defective, plain and simple it is *not* the normal state of affairs that one must accept when buying a camera without AF adjustment.
10-20-2009, 09:47 PM   #34
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QuoteOriginally posted by Marc Sabatella Quote
...
So I'm certainly not opposed to having the adjustment feature, and while I personally would rather return a defective camera than use a hack like that to try to cover up the defect, I can understand that some might prefer the cover-up over having the problem actually fixed.
.

Marc, did you read that linked article? It illustrates what I'm talking about better than I did, I encourage you to read it.

Also, it's not really a "hack" in anything after the K10D - it's a feature, one that has just recently been given a user interface through the production menu. That AF-adjust feature has actually been present in some form in every DSLR sold - it allows the service departments of Pentax/Nikon/Canon/etc to calibrate AF in the factory before release and when cameras are sent in for calibration by the owners (usually pros) after sale. It's just been made available to us to do ourselves now - in some models.

Anyway, if that feature had never been available, we'd all find ways to survive , but the fact that it is available is welcome, and desired, and is now a criteria that's important to me.

I'm not 'covering up' anything with a 'hack' - I'm using a software option thoughtfully made available to me by engineers who understand the bugbears of tolerance ranges.


.

10-20-2009, 11:05 PM   #35
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QuoteOriginally posted by jsherman999 Quote
.
Marc, did you read that linked article? It illustrates what I'm talking about better than I did, I encourage you to read it.
I read it a while back. Like I said, I agree the concept of cameras and lenses not being perfect is real. I'm just saying that, assuming one's camera is within manufacturer's spec, the *magnitude* of the problem is not such that one should expect to be unable to focus at f/2.8. Any camera or lens that was so far off as to not be able to do that isn't slightly out of calibration - it's defective.

QuoteQuote:
Also, it's not really a "hack" in anything after the K10D - it's a feature
I'm using "hack" in the computer programmer sense, not the sense of a "hacker" doing something illicit. A documented feature can be a "hack" too. Something is a "hack" if its an inelegant solution to a problem, whether the solution is documented or not. A camera can have a BF or FF problem if its AF sensors are physically misaligned. Working around a physical misalignment via software is a "hack" in this sense - the *correct* solution is to align the sensors properly. My understanding is that there are screws located on the underside of the camera that are designed to be used for this very purpose. Working around the problem via software without actually aligning the sensors properly is what I am calling a "hack" - an inelegant solution to a problem that has a much more straightforward solution.

Again, only if the sensors are *way* off am I saying they should to be corrected physically. Otherwise, the software workaround is fine - it's probably a more appropriate solution, since it's pretty doubtful one could turn the screws as precisely.

QuoteQuote:
Anyway, if that feature had never been available, we'd all find ways to survive , but the fact that it is available is welcome, and desired, and is now a criteria that's important to me.
And as I said above, I have no interest in talking anyone out of wanting tha feature. I am just trying to reassure potential customers that not having the feature does *not* mean you can't focus at f/2.8. It doesn't mean it for the K-x any more than it has meant that for the hundreds of other camera models that also lacked this feature.

QuoteQuote:
I'm not 'covering up' anything with a 'hack' - I'm using a software option thoughtfully made available to me by engineers who understand the bugbears of tolerance ranges.
If your camera's AF sensors are so far out of physical alignment that they can't focu at f/2.8, then I'd say you are indeed covering up this defect using this "hack".

But I'm guessing that's not the the case - your camera is probably *not* defective, and would be capable of focusing at f/2.8 even without adjustment. You are presumably just tightening up those tolerances. So my comment wasn't directed at uses of this menu likes yours - only uses to cover up a real hardware defect. And I'm not saying it would be immoral to do that or anything - just that there *are* better solutions if you have problems so bad that you can't focus at f/2.8.
10-21-2009, 12:18 AM   #36
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Marc, by your definition my k7, k100d and the one my brother has are all defective. The DA70 i have is OK but the da 40 may be defective. The first da40 i got, and sent back, was also defective (that one really was). I think that is more of a put off for potential customers. 3 lenses, 3 bodies, one within spec.

I don't want to offend you because you really help out here alot. And have helped me in the past but you sure seem concerned with putting of potential buyers.

mike
10-21-2009, 06:27 AM   #37
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QuoteOriginally posted by glanglois Quote
"O brave new world that has such (batteries) in't!"

I think I heard that somewhere else.

I put a set of Energizer lithiums through my K-M and got somewhat more than 1,300 exposures, using flash rather little. Perfectly pleased, particularly considering that a spare set of four is light and takes not much space. As I use AA in my flashes as well, I keep four or eight lithium spares somewhere handy in case I overlook my charging duties.

My usual AAs are Eneloops used in conjunction with a devilishly capable La Crosse Technologies charger/analyzer/fixer. I think that charger is substantially smarter than my second girlfriend. Who was quite a bit more attractive and really very nice, to be fair.

I ended up swapping bags and forgetting my spares a few weeks ago and ended up buying four lithiums for my flash in a village in the Cotswolds. Ouch. Each AA ended up more costly than a pint at the pub (my usual standard of economic comparison). Lesson learnt.
hi glanglois, you say you get about 1300 shots with lithium batteries, how many do you get with the eneloops?

thanks!
10-21-2009, 11:26 AM   #38
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QuoteOriginally posted by schmik Quote
Marc, by your definition my k7, k100d and the one my brother has are all defective.
If so, that sounds ike *extraordinarily* bad luck; sorry to hear that.

QuoteQuote:
I think that is more of a put off for potential customers. 3 lenses, 3 bodies, one within spec.
Again, it would be if it were typical. but Pentax sells many thousands (?) of cameras every year. Surely you don't think it it is the norm that most of them can't focus at f/2.8?

QuoteQuote:
I don't want to offend you because you really help out here alot. And have helped me in the past but you sure seem concerned with putting of potential buyers.
First, don't worry about offending me. Doesn't happen easily. Plus, I have the world's shortest memory when it comes to this stuff, and usually manage to quickly and completely forget just who it is I might have disagreed with and over what. As far as I'm concerned, this is purely a technical discussion, and it revolves around how much focus error should be considered within spec, and how common it is is for camera to be out of that spec. My claim is that normal spec allows a camera to focus at f/2.8, and it's pretty rare for a camera to be defective enough to not allow that. This strikes me as the "null hypothesis", meaning you'd have to have *proof* to the contrary to make a convincing case.

Anyhow, I don't see how you can say my goal here is "putting of [did you mean off?] potential buyers". Quite the contrary - my concern is that *your* statements may inadvertently be doing that, by leading to the incorrect assumption that buying a K-x means they are likely to be stuck with a camera that can't focus at f/2.8. You can buy or not buy whatever you want, for whatever reasons you like, but I don't want to see potential buyers get the idea that buying a K-x dooms them to out of focus pictures. That's just not true.

10-21-2009, 01:21 PM   #39
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QuoteOriginally posted by Marc Sabatella Quote
Again, it would be if it were typical. but Pentax sells many thousands (?) of cameras every year. Surely you don't think it it is the norm that most of them can't focus at f/2.8?
Based on my experience with the DA40 LTDs.... that is pretty close to what i think. Don't get me wrong, I love that lense. It's probably my most used. BUT when you buy a LTD lense and find lots of soft and OOF shots you start to wonder why. You test it, adjust it and all of a sudden the photos are sharp. I would never have tested it if it was great out of the box. I never said that they can't AF at f/2.8 but that the rate of OOF shots was unacceptable for a LTD lense. Yes, my experience with this has left me very sceptical about their QA

QuoteOriginally posted by Marc Sabatella:
This strikes me as the "null hypothesis", meaning you'd have to have *proof* to the contrary to make a convincing case.
.

I wish it were are as simple as just posting a photo so you could look at the focus and exif but my test shots get deleted once AF has been adjusted.

mike
10-21-2009, 01:46 PM   #40
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mike,

have you contacted Pentax about the issue? Perhaps you just have a bad copy. If Pentax receives it, says its fine, sends it back and you have the same issue - then that is a different story.

There are a lot of people here that use the DA40, even on the K2000 that doesn't have focus adjust without the debug menu, and I haven't seen any complaints.
10-21-2009, 02:22 PM   #41
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Marc, how did you get this job as moderator? Nice job you do before a tough crowd. Or as Ralph Waldo Emerson said. “Patience and fortitude conquer all things.” Oh yeah, camera talk. I am getting the Kx to upgrade from the K2000. The Kx represents a giant leap in bang for buck regardless of its shortcomings which ALL cameras have depending on what you are using it for. Having shot DSLRs since the first Canon Rebel, I find it incredible what can be bought for around $500. The Kx just can't be beat for the money or even at a lot higher price. Thanks Pentax.
10-21-2009, 02:43 PM   #42
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I got a 40 LTD. It would not take one, not even one, sharp photo at f/2.8 on my k100d. I looked up debug mode and set the focus adjust ALL the way. Better but not sharp.

I sent the lens back. I got a replacement. The replacement was about 50/50 in terms of keepers wide open. I tested and it needed adjustment, this time the adjust 'in camera' got it to be GREAT!
On the K100d it had a back focus issue.

K7 arrives.... again the DA40 is OOF. Test it. Damn the thing has Front focus on the K7.
It's the bodies that are out of whack.

I have not sent the body back. I 100% believe that Pentax Aus will say "There is nothing wrong with it, just dial in some AF adjustment and it is perfect". That is correct, with some AF adjustment it is perfect.

I have it written down how much AF adjustment that lens (and the da70) need in the debug menu on the k100d body. It's PITA to change all the time but better than OOF pictures.

@Tarsus. WHy is this a tough crowd? because we don't all hail pentax as being faultless.

FYI, did you know there is a debug setting on the K7 that allows an adjust to overall AF?
ie, if the normal range is -10 to +10 if you go to debug and add +5 then you end up with a range of -5 to +15.

Why is AF so adjustable if it is always perfect?

mike
10-21-2009, 03:01 PM   #43
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QuoteOriginally posted by schmik Quote

FYI, did you know there is a debug setting on the K7 that allows an adjust to overall AF?
ie, if the normal range is -10 to +10 if you go to debug and add +5 then you end up with a range of -5 to +15.

mike
Hi. I find this interesting. The K-7's menu has a default range of "-10 to 10". Adding an extra +5 in the debug menu will change the default menu setting from "-10 to 10" to "-5 to +15"? Will we actually see this "-5 to +15" in the menu?

So if the camera is back focusing, adding a +20 in debug will give us "+10 to 30"?
10-21-2009, 03:18 PM   #44
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It will still show -10 to +10.

"So if the camera is back focusing, adding a +20 in debug will give us "+10 to 30"?" yes. But i do not know if +20 is possible. Haven't played with it.

mike
10-21-2009, 03:58 PM   #45
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the new K-x doesnt have weather sealing does it? wondering it it may be a good upgrade from the K200D
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