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Vignetting/DLSS?????

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Chris:

It actually looks pretty good. I only posted the 48.5mm shot for comparison as the shorter focal length are even better. Have fun with your camera. http://www.pbase.com/fenwick/f707_vignetting_documentation&page=2
Regards
...Wes
Chris Gorry said:
I have placed a gallery of some test shots on the web.
I would be grateful if someone could take a look at whether the
Vignetting is as to be expected or worse.

http://www.pbase.com/chrisgorry/dlss_test_photos

Thanks,
Chris.
Click to expand...
 
Chris Gorry said:
That sample looks quite sililar to mine.
I am guessing that this is within the expected limits of the camera
(f707)?
Click to expand...
Pretty much. When you shot something that is pretty much mono-tone at full wide, you will bring out the bad of the lens easier.

My understanding is generally the more zoom a lens does, the more likely the lens will have vignetting problems. This is also why if you read any books on photograpy, most will recommends two different focual length zoom lenses.

jc
 
Your pictures show a vignetting-type banding when "posterized" (try 3 or 4 bits). I'm getting this too but it only seems to show up in large expanses of monocolor. I've tried posterizing samples from other digicams gleaned off the internet and I don't get ANY banding.

Those pictures that show DLS have the banding non-symmetrically on the lower left.

What's up with this banding -- symmetrical or otherwise? Why does it seem to be limited to the DA?

When I can get the time I think I'm going to take some photos of my computer monitor with the whole screen displaying a solid color - and try it with different colors, i.e., wavelengths, to see if the banding effects differ with wavelength. If anyone beats me to it I;ll be grateful to see the results posted.

Also, is the vignetting worse if the UV filter is in place, and at what focal lengths?

---John
 
P.S.

While I tested my camera for DLS shortly after I got it (in Dec. 2001) by shooting a uniform white wall I didn't see any evidience of it.

But now I'm starting to see some DLS in some of my more recent shots.

Any comments? Anyone else have DLS "develop" after a while?

---John
 
There have been some messages of people who "didn't notice it" early on, but then, when they looked for it, usually after reading about it here, they either saw it or thought they did. I haven't seen any reports of truly documented "development" when it wasn't there to begin with.

That said, since it seems to be a misalignment within the Lens Block Assembly that causes it, the question (re-worded) is "is it possible for the LBA to gradually become misaligned to the point where it shows up as DLS".

Interesting question; I think up til now everyone has assumed it was simply a defect in the LBA that was there from point of manufacture.

Loren
John Forish said:
P.S.

While I tested my camera for DLS shortly after I got it (in Dec.
2001) by shooting a uniform white wall I didn't see any evidience
of it.

But now I'm starting to see some DLS in some of my more recent shots.

Any comments? Anyone else have DLS "develop" after a while?

---John
Click to expand...
 
Loren,

I am quite sure, based upon a trial photo of a blank white wall (and all of the normal phots I took), that I definitely did not have DLS early on and then later began to see this syndrome in some of my pictures.

What it appears I am really getting is an off-center vignetting biased to the lower left. It does not appear to be true DLS with its dark band at the left from top to bottom. When I posterize the picture I get an off-center vignetted banding -- biased, as I said, to the lower left.

If this is the case, that the lens block assembly, or whatever, can go out of alignment (or whatever) over time then all of the folks sending their cameras to Sony for repair may be running the risk of the syndrome cropping back up, i.e., the repair may be temporary only. Of course, at this time this is all conjecture, but it bears further analysis.

I've taken very good care of my camera and it hasn't suffered any siginificant impacts (or whatever) that could be attributed as a cause for something to go out of alignment.

Has anyone else experienced anything like this?

---John
 
WOW....that brings a whole new dimension to the DLS issue, if, in fact, what you see IS DLS.

If it is not DLS, but a true progression of, for lack of a better term, moving off-centeredness (is that a word? LOL!), then there may be another syndrome storm brewing...and also if it's evident in a significant number of cameras, and not just yours.

Either way, if you're bothered enough by it, maybe you should send it in for a checkup...unfortunately, they'll charge you for it if it's out of warranty :(

Loren
John Forish said:
Loren,

I am quite sure, based upon a trial photo of a blank white wall
(and all of the normal phots I took), that I definitely did not
have DLS early on and then later began to see this syndrome in some
of my pictures.

What it appears I am really getting is an off-center vignetting
biased to the lower left. It does not appear to be true DLS with
its dark band at the left from top to bottom. When I posterize the
picture I get an off-center vignetted banding -- biased, as I said,
to the lower left.

If this is the case, that the lens block assembly, or whatever, can
go out of alignment (or whatever) over time then all of the folks
sending their cameras to Sony for repair may be running the risk of
the syndrome cropping back up, i.e., the repair may be temporary
only. Of course, at this time this is all conjecture, but it bears
further analysis.

I've taken very good care of my camera and it hasn't suffered any
siginificant impacts (or whatever) that could be attributed as a
cause for something to go out of alignment.

Has anyone else experienced anything like this?

---John
Click to expand...
 
Loren Charif said:
WOW....that brings a whole new dimension to the DLS issue, if, in
fact, what you see IS DLS.

If it is not DLS, but a true progression of, for lack of a better
term, moving off-centeredness (is that a word? LOL!), then there
may be another syndrome storm brewing...and also if it's evident in
a significant number of cameras, and not just yours.
Click to expand...
Loren,

I do believe what I am seeing is what people are calling DLS. Can anyone show me a DLS shot without the off-center banding revealed in posterizing?

I think ALL DLS is just this off-center vignetting, and that the degree of it seems serious.

Chris Gorry's original post to this thread:

http://www.dpreview.com/forums/read.asp?forum=1009&message=2560806

provides a link to his galleries with exactly the same effect as I am seeing.

And another of my main points is -- I don't see this type of banding in pictures from other brands of digicams -- not at all and yet it is very strong in the DA -- but it only seems to happen in wide expanses of bright light monocolor like a sky or a wall.

---John
 
What I was responding to was the progression oof going from not having DLS to having it, and the banding.

As for DLS just being off-center vignetting, I'd have to disagree; most of the severe cases of DLS that we've seen are a fairly steady width of darkness from top to bottom; if it were vignetting, the band would narrow near the middle (top to bottom) of the screen.

The other issue is that some cameras show it much more severely than others; theoretically, if it were "just" vignetting, it should be pretty close to the same in all cameras, shouldn't it?

Also, the tech who seems to be the DLS guru at Sony in Westwood, MA, when i originally showed him several prints to illustrate my case of DLS, picked some out as definitely DLS, yet others were "normal" vignetting...so Sony recognizes a difference.

I dunno...just my thoughts...either way, it's a real problem, and my guess is that, at some point, if Sony doesn't stop shipping DLS-afflicted cameras, it has to hurt them.

Loren
John Forish said:
Loren Charif said:
WOW....that brings a whole new dimension to the DLS issue, if, in
fact, what you see IS DLS.

If it is not DLS, but a true progression of, for lack of a better
term, moving off-centeredness (is that a word? LOL!), then there
may be another syndrome storm brewing...and also if it's evident in
a significant number of cameras, and not just yours.
Click to expand...
Loren,

I do believe what I am seeing is what people are calling DLS. Can
anyone show me a DLS shot without the off-center banding revealed
in posterizing?
I think ALL DLS is just this off-center vignetting, and that the
degree of it seems serious.

Chris Gorry's original post to this thread:

http://www.dpreview.com/forums/read.asp?forum=1009&message=2560806

provides a link to his galleries with exactly the same effect as I
am seeing.

And another of my main points is -- I don't see this type of
banding in pictures from other brands of digicams -- not at all and
yet it is very strong in the DA -- but it only seems to happen in
wide expanses of bright light monocolor like a sky or a wall.

---John
Click to expand...
 
John Forish said:
I do believe what I am seeing is what people are calling DLS. Can
anyone show me a DLS shot without the off-center banding revealed
in posterizing?
I think ALL DLS is just this off-center vignetting, and that the
degree of it seems serious.
Click to expand...
This should be something with your own tracking you can determine. Since you said you are noticing a development of it, how does the development looks like? Is it moving from left to right causing larger DLS bands, or is it causing the DLS band to have more and more red tint as time goes on? Or is it both?

jc
 
Jimmy Chen said:
This should be something with your own tracking you can determine.
Since you said you are noticing a development of it, how does the
development looks like? Is it moving from left to right causing
larger DLS bands, or is it causing the DLS band to have more and
more red tint as time goes on? Or is it both?

jc
Click to expand...
Jimmy,

I don't know yet. I've just started picking up on the fact that it is there in some pictures -- and it definitely wasn't previously (as attributed to by a purposeful test).

I'll keep you posted as I make more observations and tests.

---John
 
Loren Charif said:
What I was responding to was the progression of going from not
having DLS to having it, and the banding.

As for DLS just being off-center vignetting, I'd have to disagree;
most of the severe cases of DLS that we've seen are a fairly steady
width of darkness from top to bottom; if it were vignetting, the
band would narrow near the middle (top to bottom) of the screen.
Click to expand...
Loren,

What I'm saying is that in all of the DLS samples (mine and those posted) I've played with via "posterizing" the bands do seem to narrow in the middle (as in the form of concentric circles). Please point me to a photo where this is otherwise (where the darkening is parallel rather than concentric). I would love to analyze it using my methods and report back to you on the results. At this time I don't have any experiments rigorous to post but I'm planning a series of scientific (method) tests to establish how this vignetting phenomenon is exhibited by my DA.
Loren Charif said:
The other issue is that some cameras show it much more severely
than others; theoretically, if it were "just" vignetting, it should
be pretty close to the same in all cameras, shouldn't it?]
Click to expand...
Not if it is something in the lens and/or CCD is going out of alignment/adjustment. Plus, how do the camera's sampling algorithms affect the outcome -- are they responsible, in whole or part, for the banding (that I don't see on other cameras)?
Loren Charif said:
Also, the tech who seems to be the DLS guru at Sony in Westwood,
MA, when i originally showed him several prints to illustrate my
case of DLS, picked some out as definitely DLS, yet others were
"normal" vignetting...so Sony recognizes a difference.
Click to expand...
I think they/we are just calling centered vignetting "normal" and off-centered vignetting "DLS" -- why it is always to the left I don't know but maybe something in the camera's design/construction allows it to go out of alignment only in the one direction -- I'm not sure how to determine this, but the empirical evidence is that it only goes to the left (anyone have DRS?).

Also, importantly, I don't see any kind of banding in shots from other cameras to compare, even with the on-centered ones, to the Sony 707. Why is this?

---John
 
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