1Ds MKIII and Optical Low Pass filtering

[Ray]

Experimental error? Lens effects? OLPF tolerances? Who knows?

Graeme
[a href=\"index.php?act=findpost&pid=154396\"][{POST_SNAPBACK}][/a]

Okay! I thought you might   .

[Graeme Nattress]

The only camera I have control over, and have the engineering specs of, measures the same either  direction, so I've not had the problem to look into it further.

Graeme

[Hägar the horrible]

Regarding the small pixel pitch of the new camera I wonder what is the impact of lens diffraction on moire and artefacts. Theoreticaly could you avoid moire by stopping down to f11?


Hey, my first post here, I am allowed to ask stupid questions

[Graeme Nattress]

Stopping down to deliberately get diffraction to limit the resolution hitting the sensor would have the same effect as an optical low pass filter. If you always shot stopped down, removing the OLPF would make sense as then you'd not get double the effect.

Graeme

[jorgedelfino]

Why don't you guys go out and take some pictures? I own a 1ds2 and a 40D, plus some 10K$ of L lenses... so far the only limitations I see are my own skills! the rest is bullshit!
saludos!

[Ray]

Why don't you guys go out and take some pictures? I own a 1ds2 and a 40D, plus some 10K$ of L lenses... so far the only limitations I see are my own skills! the rest is bullshit!
saludos!
[a href=\"index.php?act=findpost&pid=154543\"][{POST_SNAPBACK}][/a]

Seems rather a waste of money to buy a 1Ds2 and 40D if you are only limited by your own skills. Surely a P&S camera would be sufficient.

[Mark D Segal]

Oooooooooooooo  -  that was "the unkindest cut of all" - (but I just stopped laughing)  

Chiang Mai must be doing good things for you.

[Ray]

Mark,
I'm glad someone appreciates my humour   .

I'm pretty relaxed here in Chiang Mai, probably because I have no deadlines to meet, can take my own time and change plans at will now I've reached retirement age. I might even pay another visit to Angkor Wat in the next few weeks   .

[Mark D Segal]

I'm pretty relaxed here in Chiang Mai, probably because I have no deadlines to meet, can take my own time and change plans at will now I've reached retirement age. I might even pay another visit to Angkor Wat in the next few weeks   .
[a href=\"index.php?act=findpost&pid=154577\"][{POST_SNAPBACK}][/a]

Sounds idyllic. One of these days again...........

[ashdavid]

I hope you were joking about this too? I mean, if that choice were offered would you know how, or put otherwise, what would it take for anyone to know how to do so intelligently?
[a href=\"index.php?act=findpost&pid=154377\"][{POST_SNAPBACK}][/a]

I don't see the problem?  If the subjects that you shoot are less prone to moire then it could be in your best intrests to choose a weaker AA filter( If you could ever actually do this) And most people who are buying a camera of this level will have some idea about what they do and don't like about thier pics especially in regards to moire.

Should I interpret your statement as you would not know how to choose between light and heavy filtering?

[John Sheehy]

Stopping down to deliberately get diffraction to limit the resolution hitting the sensor would have the same effect as an optical low pass filter. If you always shot stopped down, removing the OLPF would make sense as then you'd not get double the effect.
[a href=\"index.php?act=findpost&pid=154533\"][{POST_SNAPBACK}][/a]

It's more like redundancy, after a certain point.  You can't really soften what is already soft by any significant amount, especially when the cut-off is fairly sharp.

[Ray]

I don't see the problem?  If the subjects that you shoot are less prone to moire then it could be in your best intrests to choose a weaker AA filter( If you could ever actually do this) And most people who are buying a camera of this level will have some idea about what they do and don't like about thier pics especially in regards to moire.

Should I interpret your statement as you would not know how to choose between light and heavy filtering?
[a href=\"index.php?act=findpost&pid=154593\"][{POST_SNAPBACK}][/a]

I think the problem here is a Catch 22 situation. If Canon were able to manufacture a device so sophisticated that you could dial in AA filter strength settings, they could probably gives us an oversampling, low noise 50mp sensor that would have no need for an AA filter. Maybe with future developments in Nanotechnology this will eventually be possible.

Here's a schematic diagram of an AA filter from the Canon website. As you can see it's a pretty sophisticated device with many sandwiched layers and also acts as a protective layer to the sensor.

[attachment=3939:attachment]

[ashdavid]

I think the problem here is a Catch 22 situation. If Canon were able to manufacture a device so sophisticated that you could dial in AA filter strength settings, they could probably gives us an oversampling, low noise 50mp sensor that would have no need for an AA filter. Maybe with future developments in Nanotechnology this will eventually be possible.

Here's a schematic diagram of an AA filter from the Canon website. As you can see it's a pretty sophisticated device with many sandwiched layers and also acts as a protective layer to the sensor.

[attachment=3939:attachment]
[a href=\"index.php?act=findpost&pid=154616\"][{POST_SNAPBACK}][/a]

I can understand that. I was thinking along the lines of having say two sensors to choose from before you buy, one being only mildly filtered and the other lets say the same as what comes with the camera standard these days.

[Mark D Segal]

Should I interpret your statement as you would not know how to choose between light and heavy filtering?
[a href=\"index.php?act=findpost&pid=154593\"][{POST_SNAPBACK}][/a]

Not quite. Perhaps I was a bit "telegraphic". To explain the point more fully, there is at least one camera maker which does offer a choice of with/without the filter. In that case they can tell you quickly and easily about the implications of the choice. If it were to be more refined than that - say three options: heavy filter, light filter, no filter, we are entering new territory and along with that users - even sophisticated ones - would need to be more carefully educated about the extent to which problems are likely to occur or not occur and what to do about them as a function of the filter choice they make. Then having made that choice, once they see the results they may or may not be happy about it, which adds a layer of issues to after-sales support for the camera manufacturer - either exchanging the camera or replacing the filter, and at whose cost? I know we're just talking hypothetical stuff here, but once such an idea is raised, which may indeed not be a bad idea, it is also worthwhile trying to conjure the implications at the same time. That can shed light on whether the idea is likely to see the light of day (pun intended). Hope that helps.

[ashdavid]

Not quite. Perhaps I was a bit "telegraphic". To explain the point more fully, there is at least one camera maker which does offer a choice of with/without the filter. In that case they can tell you quickly and easily about the implications of the choice. If it were to be more refined than that - say three options: heavy filter, light filter, no filter, we are entering new territory and along with that users - even sophisticated ones - would need to be more carefully educated about the extent to which problems are likely to occur or not occur and what to do about them as a function of the filter choice they make. Then having made that choice, once they see the results they may or may not be happy about it, which adds a layer of issues to after-sales support for the camera manufacturer - either exchanging the camera or replacing the filter, and at whose cost? I know we're just talking hypothetical stuff here, but once such an idea is raised, which may indeed not be a bad idea, it is also worthwhile trying to conjure the implications at the same time. That can shed light on whether the idea is likely to see the light of day (pun intended). Hope that helps.
[a href=\"index.php?act=findpost&pid=154662\"][{POST_SNAPBACK}][/a]

As I suspected, your statement was one of general speaking. And I do believe if there was ever something like this , the uniformed would probably be the first to critisise others over there own bad decision.

As there are no pro canon bodies without the filter, a little bit of trial and error would come into play I suspect.

Anyway, I know where you are comming from, I just thought I should respond to get clarification, thanks.

[AJSJones]

Here's a schematic diagram of an AA filter from the Canon website. As you can see it's a pretty sophisticated device with many sandwiched layers and also acts as a protective layer to the sensor.

[attachment=3939:attachment]
[{POST_SNAPBACK}][/a]

[a href=\"http://www.sensor-film.com/filter.html]Here's[/url] a close-up photograph of the beasts for the 20D/30D and the 5D.  The thickness of the 5D's OLPFs is greater than that of the 20/30D, in roughly the proportion of their pixel spacing, suggesting the goal of the designers was to keep the "strength" related to the need to shift 1 pixel in each axis.  BTW , that's why I'm always interested in how folks assess the "strength" of the effect... Approximating a 1 pixel shift in software (in PS for example ) last couple of posts here  produces a very benign softening

Andy

[Rob C]

Mark,
I'm glad someone appreciates my humour   .

I'm pretty relaxed here in Chiang Mai, probably because I have no deadlines to meet, can take my own time and change plans at will now I've reached retirement age. I might even pay another visit to Angkor Wat in the next few weeks   .
[a href=\"index.php?act=findpost&pid=154577\"][{POST_SNAPBACK}][/a]

Ray

All funnies aside, don´t take ´retirement age´ with too much complacency: it creeps up to you and then slowly, without you noticing a damn thing, it has you THINKING retirement age; once there it is virtually impossible to regain the previous innocence. I know.

Rob C

[Mark D Segal]

Ray
 once there it is virtually impossible to regain the previous innocence. I know.

Rob C
[a href=\"index.php?act=findpost&pid=154754\"][{POST_SNAPBACK}][/a]

What makes you think he was innocent before retirement?  

[Ray]

What makes you think he was innocent before retirement? 
[a href=\"index.php?act=findpost&pid=154765\"][{POST_SNAPBACK}][/a]

Mark,
I was born innocent. It seems that some people are direct descendants of Adam and Eve and are born with lots of original sin, and some are direct descendants of ape-like creatures who lived in Africa about 5 million years ago and are born innocent.

Phew! Talk about getting off topic  .

[Ray]

The thickness of the 5D's OLPFs is greater than that of the 20/30D, in roughly the proportion of their pixel spacing, suggesting the goal of the designers was to keep the "strength" related to the need to shift 1 pixel in each axis.  BTW , that's why I'm always interested in how folks assess the "strength" of the effect... Approximating a 1 pixel shift in software (in PS for example ) last couple of posts here  produces a very benign softening

Andy
[a href=\"index.php?act=findpost&pid=154741\"][{POST_SNAPBACK}][/a]

Interesting! I didn't realise there was another forum discussing the same issue more or less contemporaneously. I guess I spend too much time on LL and have no time to look at other forums. I haven't visited Photo.net in a year or so and my subscription has probably expired.

I noticed one comment from 'Jeff' that seemed very counter-intuitive, but I didn't see anyone correcting him on the NatureScapes forum.

The problem is that no AA or a weak AA filter causes some pretty serious moire, particularly as pixel size decreases. For this reason, the AA filters tend to get somewhat stronger as pixel size decreases, creating a bit of diminishing returns at least with regard to detail at very small spatial frequencies.

I take it he's got this backwards?