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04-29-2011, 03:08 PM   #46
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just thought I'd add

That Amy's photos were one of the reasons I picked up a K-r after my K-m and associated gear were stolen. I found my way to her K-x stills by accident, really, and was inspired.

I figured if I worked hard enough at my photography skills, and eventually plied some of her post processing techniques from her , I'd be able to produce images worthy of the ones she tosses off daily on Facebook!

Back to unabashed lurking-fan mode. Keep on, Amy!

-s

04-29-2011, 06:37 PM   #47
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I think our most prominent Leica shooter here is Mel. We should make other Leica people apply for her approval before they can have Pentax. They'll eat it up.
04-30-2011, 01:36 AM   #48
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QuoteOriginally posted by Christine Tham Quote
AA filter removes information
You seem to know little about the math involved or about what information is. Otherwise, you wouldn't have made that statement. I tried to explain when an AA filter removes information and when it does not. E.g., a discrete linear blur operator may or may not have 'zero' eigenvalues (or very small ones). You may want to read about what people did to treat the optics flaw in the first Hubble scope installment, too.
04-30-2011, 02:25 AM   #49
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QuoteOriginally posted by falconeye Quote
You seem to know little about the math involved or about what information is. Otherwise, you wouldn't have made that statement. I tried to explain when an AA filter removes information and when it does not.
Does it really matter? No matter what you do to an image after the AA filter has been applied, it will never be exactly the same as an image before the AA filter has been applied. Therefore it will ALWAYS be a "pies vs apples" comparison.

My knowledge, or lack of, is not really relevant to the discussion.

Of course, if you do have "proof" that AA is a totally reversible transformation (in the sense that it can be 100% "undone") please show us.

04-30-2011, 03:29 AM   #50
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QuoteOriginally posted by Christine Tham Quote
My knowledge, or lack of, is not really relevant to the discussion.
This pretty much ends the discussion of this topic for me. Probably for the better of the thread It was off-topic to start with. My fault

P.S.
As far as proof is concerned, sorry that I don't start a math lecture for you. However, if you are interested in the topic, you may start your read here: http://en.wikipedia.org/wiki/Deconvolution To make things clearer: not every image alteration removes information. Some do, some don't. E.g., inversion of colors does not. To repeat myself: an AA filter can remove information (and with noise always does to a certain degree which is why low iSO is important), but it can be taylored such that no information is lost at spatial frequencies below the Nyquist frequency.


As far as this thread goes: I only wanted to hint at the fact that K-5 images should be sharpened more in the RAW converter than Leica M8/9 images to obtain respective best results. And that it is best to compare best results.

Last edited by falconeye; 04-30-2011 at 03:52 AM.
04-30-2011, 12:08 PM   #51
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QuoteOriginally posted by falconeye Quote
To repeat myself: an AA filter can remove information (and with noise always does to a certain degree which is why low iSO is important), but it can be taylored such that no information is lost at spatial frequencies below the Nyquist frequency.
In other words, you have no proof. Thanks for the clarification.

As for tweaking the image of one camera to ensure a "fairer" comparison, do you want to adjust for different sensor resolutions, different DOF because of full frame vs APS, different contrast, etc. as well? All of which will probably yield a greater difference than what you advocate? (I mean, you are talking about enhancing 5% of detail close to Nyquist, right?)
04-30-2011, 02:15 PM   #52
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Amy, I love that gull picture.
04-30-2011, 04:11 PM   #53
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QuoteOriginally posted by Christine Tham Quote
In other words, you have no proof. Thanks for the clarification.
Don't cite me wrong.
You are a difficult person to communicate with.

04-30-2011, 05:36 PM   #54
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QuoteOriginally posted by falconeye Quote
Don't cite me wrong.
You are a difficult person to communicate with.
I didn't cite you wrong. You didn't provide any proof that an AA filter is "totally reversible transformation (in the sense that it can be 100% "undone")."

If you don't want to post in the thread, send me your proof by PM.

I don't need any maths - although I do have a major in Pure Maths and I am somewhat familiar with what you are talking about.

All you need to do is start with an image taken with no AA filter (with frequency information extending past Nyquist), apply AA, apply your deconvolution, and show me you will get back the original image, with every pixel restored.

Note: this implies restoration of frequencies above Nyquist (and yes, I am aware by Shannon's theorem that there is no "useful" information above Nyquist) because otherwise it's still an unfair comparison - you are comparing one image with frequencies above Nyquist (implying presence of aliasing artefacts) with another image that is sharpened, but filtered.

Making claims like there's an extra 5% of detail around Nyquist that could potentially be recovered ... Sorry, not really relevant given there are so many other factors affecting image quality between the two cameras that any improvement would be insignificant.

Last edited by Christine Tham; 04-30-2011 at 05:54 PM.
04-30-2011, 05:46 PM   #55
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QuoteOriginally posted by Christine Tham Quote
Making claims like there's an extra 5% of detail around Nyquist that could potentially be recovered
Don't cite me wrong.
You are a difficult person to communicate with.
04-30-2011, 05:54 PM   #56
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No offense intended, Christine, but Falk is the recognized guru around here for the technical aspects of a camera or lens. I'm not saying he can't possibly be wrong, but it does seem unlikely. He's proven repeatedly that he knows his stuff.
04-30-2011, 05:57 PM   #57
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QuoteOriginally posted by falconeye Quote
Don't cite me wrong.
You are a difficult person to communicate with.
For reference, this is what you actually said:
QuoteOriginally posted by falconeye:
With an excellent lens, the remaining overall contrast at Nyquist is still well above zero, say above 5%.
04-30-2011, 06:03 PM   #58
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QuoteOriginally posted by DogLover Quote
No offense intended, Christine, but Falk is the recognized guru around here for the technical aspects of a camera or lens. I'm not saying he can't possibly be wrong, but it does seem unlikely. He's proven repeatedly that he knows his stuff.
No offense taken, and I don't claim to know more than Falk.

However, he made a statement. I expressed skepticism. The onus is on him to substantiate the statement.

I don't appreciate his comments about my level of knowledge, because frankly it's irrelevant whether I know more or less than him. Surely it is possible for him to justify a claim that he made without resorting to that?
04-30-2011, 06:42 PM   #59
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QuoteOriginally posted by DRabbit Quote
Hi!
Yeah I posted the photos here first actually

Actually, Steve, Jim Radcliffe, Ashwin, Jono... And others... All Leica users I've come to know through various forums seem to enjoy the k5 a lot too. Steve doesn't own one, but he loved it when he reviewed it a while back. There's quite a few of us in the Leica crowd that seem to love-us some Pentax

And there's a lot to like about the k5 + 43 combo... Makes me want the 31 all the more!
Much like in the old days, when many European Leica dealers only carried one non-Leica camera, the Pentax LX, which was seen as the right supplement to a Leica M series, in particular for telephoto!

Perhaps the K-5 becomes the telephoto accessory for Leica M8/M9 owners?!
05-01-2011, 03:39 AM   #60
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QuoteOriginally posted by falconeye Quote
Don't cite me wrong.
You are a difficult person to communicate with.
To be fair Falc, as much as I enjoy reading your blog, you do talk far too much in figures and maths where as for most photography is pragmatic regarding images produced and an artform based on capturing a moment .
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