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12-03-2010, 08:18 PM   #76
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QuoteOriginally posted by Class A Quote
I agree with Falk, how about if people that think something is wrong or people who would like to promote that something is wrong do something to show there is merit to their claim? It's got to be more than a terrible picture, though; anyone can produce these if they want to.

The fact that among the three of the "charges" you mentioned, two have already been dismissed and you still mention them seems to indicate that proving innocence is not only doing things the wrong way round but also ineffective.

P.S.: I agree, let's cut Ogl some slack. Let him wait for the camera he is a 100% happy with independent of whether or not the K-5 would be sufficient for him in practice. The K-7 would have been fine for me -- hey the K100D is! -- but I skipped it because I wasn't 100% convinced. Now I'll get a better version that was worth the wait.
Cut him some slack? All the guy does is endlessly bash every Pentax camera and thinks every picture is soft or blurry. And without any proof or merit to his claims, he just sounds like a big troll. I was amazed to see he actually praised the K-5 for a while after it first came out, then, as usual, found some ridiculous thing wrong with it, and began the next bashing campaign. It's just tired, and ruins threads IMO.

All of this uber-geeky nitpicking over sub-pixels is a bit much. People need to spend more time outside, taking actual pictures, and less time trying to find fault with everything.

12-03-2010, 08:22 PM   #77
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QuoteOriginally posted by JohnBee Quote
I think you may be overly sensitive here.
Sometimes subtle differences in wording make all the difference to me. The way you referenced the "issues" almost implies that they exist or that there was sufficient evidence to start investigations. I would have, e.g., written "If someone claims that there is an issue with the AA filter, let's examine that claim."
I'm alright if someone feels that I'm being over-sensitive here, because I might have just misinterpreted what you wrote.

QuoteOriginally posted by JohnBee Quote
Are you perhaps subject to sensitivities toward specified product criticisms?
No, I bought a Pentax camera because it made the right trade-offs for me. I was impressed by the value for money ratio. Since then, I wasn't always happy with recent Pentax developments (e.g., lens prices) and sometimes wonder whether I should have went for SONY because then I would have been able to mate my glass with a A900 sooner or later. But the fact that Pentax managed to create the K-5 is very promising for the future.

I'm sensitive regarding non-issues being brought up again and again, even if it is just in discussions like this one.

I agree that it is nice if someone goes through the trouble and disproves an alleged shortcoming. However, a) you cannot expect people to react to every silly allegation and b) no matter what you do, there will always people who will not be convinced by work that disproves an issue. The latter is not to say that it is not worth trying, but certainly the onus to make a point should be on the people who claim there is a problem, not on others to tell them that they are wrong.
12-03-2010, 08:33 PM   #78
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QuoteOriginally posted by Class A Quote
I would have, e.g., written "If someone claims that there is an issue with the AA filter, let's examine that claim."
Well that does seem like a better fit. Though in my defense. I'd like to share that I am not well versed in the English written language(not my native tongue) and that it often ends-up producing awkwardly worded sentences. A stark reminder, that it takes more than a spell check to effectively get a point across a language barrier
QuoteQuote:
I agree that it is nice if someone goes through the trouble and disproves an alleged shortcoming. However, a) you cannot expect people to react to every silly allegation and b) no matter what you do, there will always people who will not be convinced by work that disproves an issue. The latter is not to say that it is not worth trying, but certainly the onus to make a point should be on the people who claim there is a problem, not on others to tell them that they are wrong.
Yes, exactly! And keep in mind that not all rumors are worthy of addressing. I can't count the ones that never seem to get anywhere(Pentax doomsday, scratched sensor(or AA filter) conspiracy etc etc.). But in some cases however, it occurs where people come across claims that are more convincing than usual and they end-up affecting(misleading) prospects in the process. And it is at this juncture that I think avoidance does no one any good.

Last edited by JohnBee; 12-03-2010 at 09:11 PM.
12-04-2010, 05:35 AM   #79
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I'd like to thank you, Falk, for your work on this. It looks to me as though you have shown that on the K5 that this will be a non issue. Truthfully, I haven't seen it on the K7 in my shooting, but that isn't to say it isn't there. The thing about blur, is that I am likely to delete photos with it fairly quickly, without trying to analyze if the issue was camera shake or, something else. Most of the time, blur is the result of user (my) error and has nothing to do with the camera at all.

It is really important with all of the "issues" that are mentioned by John Bee, to figure out if they have real world significance. A medication may have a side effect that occurs in one in a million users of the medication. The fact that it is infrequent does not change the fact that it is a side effect, but it does mean that it is unlikely to occur in a normal physician's practice. I'm OK for looking for problems as long as we also make it clear if these problems will be visible in normal photographic situations.

By the way, John, I think you (and many others for whom English is not their mother-tongue) do wonderfully well at expressing yourself.

12-04-2010, 09:07 AM   #80
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A couple of things to consider when analyzing any problem with any piece of equipment, but I think especially cameras.
Most people just plain don't know how to run a test, they don't follow a scientific method, and they are unable to properly test for a single variable.
In the case of testing for blur, there are about half a dozen things that can cause it, and if you want to find out if cause #6 is the problem, then cause #1 through #5 have to be completely eliminated from the equation.
This is where most people fall down. They misfocus very slightly, they don't use a lens appropriate to testing anything, their tripod isn't sufficient to hold a camera steady, the furnace or air conditioner is running, there is a slight breeze, a car drives by, etc.
Then they come up with a result, which on the surface appears to support their contention, but which in actuality fails because they didn't eliminate every variable but the one they were testing for.
Falk is one of the very few people who's results I would trust, simply because the method he describes using matches the criteria required to make a scientific test.
Some Russian dud who tosses a camera on a tripod of unknown quality and takes a picture in unknown and uncontrolled conditions doesn't make the grade for a scientific test and only proves he doesn't know what he is doing with a camera.

Really, for most of us (myself included) the best test of our gear is to go out and take pictures. At some point we might take one that looks bad that we can blame on the gear, and what we will learn is to not use the gear that way.
For example, I learned a lesson about 40 years ago, long before digital cameras were even dreamed possible by most mortals, was that I shouldn't take pictures of naked tree branches against an overcast sky.
This lesson had nothing to do with purple fringing, or chromatic aberration or any of the other things that people whine about now.
The lesson learned was that this sort of picture was ugly to look at.
Consequently, I think anyone who takes such a picture and then whines that there is a problem is a fool.
Not because they bought the wrong camera, but because they have deliberately taken an ugly picture.
That it shows an optical problem is, for me, completely secondary.
The same with induced blur. If, in the real world of photography, you notice that under certain conditions your camera is showing blur, then avoid those conditions.
As an example, my Super program film camera has very bad blur (caused by mirror slap, I suspect) between 1/4 and 1/60 second when used vertically.
Bad enough that it takes a 15 pound Zone VI Standard wooden tripod to tame.
This camera was fine under every other condition, so I didn't shoot verticals with it at the shutter speeds that were problematic for it.
This solution is simple, and elegant in that it plays to the strengths of the camera and doesn't try to force it into something that it doesn't do well.
Every camera has some weakness.
The weaknesses of the K5 are very well documented now, and people will look at these weaknesses and decide to buy some other camera from some other brand because of it.
If they buy a Canon 7D, they will have to tolerate low ISO banding, if they buy a Nikon d7000 they will have to tolerate hot pixels, etc.
It's the way of the world, we so want to buy perfection, we just don't seem to realize that it doesn't exist at any price.
And the internet doesn't help, since if a person can set up a slick website and set themselves up as self ordained experts, they can get drunk on Irish Cream and take out of focus pictures with a new camera and proclaim it unable to take sharp pictures.
And many people, will trust them because they are the experts who say it is true, and will believe them over the legions of people who are taking sharp pictures because these people have poor HTML skills.
It's quite funny really.

Last edited by Wheatfield; 12-04-2010 at 09:23 PM.
12-04-2010, 09:18 AM   #81
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Wheatfield: well done!

"Scientific method" is rather a stranger here, alas.

I'm perfectly happy to let the photographers teach me about photography and the scientists about the science. They're both fascinating.

It's when the photographers try to teach us (non)science that we get wrapped up in silly disputations. They really need to think twice before making their proclamations re: testing.

We're very lucky to have a few people that live comfortably in both camps.

You said it well. Thanks.

GJL
Who is neither a photographer nor a scientist
12-04-2010, 12:45 PM   #82
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QuoteOriginally posted by Wheatfield Quote
Some Russian dud who tosses a camera on a tripod of unknown quality...
Applies to non-Russian dudes as well.

QuoteOriginally posted by Wheatfield Quote
... they can get drunk on Irish Cream and take out of focus pictures ...
"Irish Cream" That was precious.

Last edited by Class A; 12-04-2010 at 01:44 PM.
12-04-2010, 01:27 PM   #83
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QuoteOriginally posted by Wheatfield Quote
And the internet doesn't help, since if a person can set up a slick website and set themselves up as self ordained experts, they can get drunk on Irish Cream and take out of focus pictures with a new camera and proclaim it unable to take sharp pictures.
What if the tester just simply has a really really obnoxious afro and by his own holy cuteness, knows more than anyone else does?

Jason

12-04-2010, 01:34 PM   #84
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I've been looking forward to this thread - it's obvious it takes quite a bit of effort and understanding to gather this data.

Thanks falconeye!
12-07-2010, 07:56 AM   #85
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I don't normally do this. Esp. if sitting in the glass house.

But I notice this sentence:

QuoteQuote:
85mm f 5,6 1/80s my pictures are sharper without VR (!!)
It's from this thread:
blurred pics on D7000 with VR switched on: Nikon D90 - D40 / D7000 - D3000 Forum: Digital Photography Review

I.e., it is from a D7000 user using a 16-85mm lens. I've mentioned (in my report) that shutter-induced body acceleration can affect a floating VR lens element too. Obviously, in the Nikon lens, switching VR off fixes the vibration enough to mitigate the problem. But like with the K-7, shutter-induced blur can make shake reduction ineffective in the critical region. It's considered solved for the K-5 now.

However, the user may simply be wrong and his post sends me on a wrong track.

So, my question is: Are there more reports of ineffective VR/IS around 1/100s? Would be interesting to know in the context of this thread.
12-07-2010, 08:25 AM   #86
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Perhaps someone would ask that question in the Nikon/Canon forums, as well.

That would put a cat amongst the pigeons!
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