I'm uncomfortable with Panasonic...

more specifically, the way Panasonic handles LX3

two weeks ago, I bought an LX3 with the money I got from a photo competition, I was trying out the camera and found the image a bit on the softside, especially compared with other high end dc at base ISO.
I was wondered until I saw this thread:

http://forums.dpreview.com/forums/readflat.asp?forum=1033&message=29656701&changemode=1

It was a big surprise to me as I have never seen a lens (not fish eye) producing so much distortion, and also I cannot believe Panasonic did an automatic processing with RAW in silkpix to correct the distortion and vignetting without notifying users.

[img] http://static.zooomr.com/images/6109899_27b2e80ef5.jpg[/img]

so I did an experiement, the picture was took in 3:2 aspect ratio, and decoded with dcraw. To correct it to match silkpix output, I have to apply +16 in photoshop lens correction, and crop out about about 20% of the pixels.

Now, I got a image with 8 million pixels (and pansonic says effective pixel is about 10 million), which means there are 2 million pixels never shows up in a usable image and silkpix just interpolated the image to 10 million.
Needless to say, this will degrade picture quality.

It's hard to say the lens quality is good, as it has so much distortion. While Panasonic has decided to produce it with such a good specification to attract attention, and in the later stage modify the RAW image (without notifying) to cover its weakness (and in the mean time degrade pic quality), the producer touted the LX3 produces image with " ...high resolution and minimal distortion and artifacts..."

I don't know if other producers also do this, but it seems to me the way panasonic markets this cameras is being dishonest.

photo doesn't appear..

How does panasonic manage to get a 10 million pixel photo, after lens correction from the original 10 million pixel photo? the only way is to cut and interpolate with "guess pixels"...

there is a limit, when passed, the so called correction causes more problem. And in this case, the correction removes 20% of the total pixels...I don't see leica and Nikon do that. and BTW, when Leica and Nikon did that, they made it clear what was happenning, so consumer can make an informed decision.

wow, it llooks like PTL has done a wonderful job...
hope the software is an easy-to-use one not like dcraw @ @

but how come lens correction in PS3 cropped so much...
I got 9629172 pixels in a 3:2 image before cropping in PS
and 7846416 pixels after...

hmm...I don't think so... the image is wider with 16:9

and correct Jpeg is one thing, automatically correct RAW without notifying user is another. Everybody knows every manufacturer correct something in jpeg, but seldom modify RAW. To me it's like panasonic is trying to cover the lens's weakness

Ehrik wrote:

PTLens author Thomas Niemann
said that dcraw outputs the same pixel width data
for all three aspects. Since this is the first raw capable
camera with multi-aspect, I think it's possible dcraw
may have made an oversight, not outputting all
available pixels at 3:2 and 16:9.

The images wouldn't be horizontally wider at 16:9 and 3:2
unless more of the sensor width was utilised. And the sensor
would be needlessly large.

BTW Panasonic correcting lens flaws when they make their
JPEGs has not been a secret. They even talked about it in
an article about the Venus 2 engine long ago.

Just my two oere
Erik from Sweden

please read my main post, I'm talking about RAW, which should reveal the true characteristic of the cam, rather than jpeg. By modifying RAW, panasonic successfully hide the distortion of the lens, which is misleading. it is difficult for panasonic to tell the user while doing correction

and FYI, distortion correction certainly degrades the IQ (detail), that's why rich people buy expensive lens which are distortion "free" rather than getting a cheap one then correct is using some software

Midwest wrote:

Ehrik wrote:

BTW Panasonic correcting lens flaws when they make their
JPEGs has not been a secret. They even talked about it in
an article about the Venus 2 engine long ago.

Very true Ehrik. Besides, isn't that basically the way most digital
cameras work anyhow? They are designed to produce the best image they
can, and that generally includes processing to get rid of distortions
etc. You don't have that capability with a film camera so the lenses
have to be the best (and costliest).
A digital camera is a system unto itself. It creates images. The lens
is only one stop along the route and should be as sharp as possible
(lost detail cannot be recreated) first and foremost. Other issues
(i.e. distortion and CA) can be dealt with downstream, and most
certainly are. Ideally, any weaknesses in the image created by the
lens are matched by appropriate processing within the camera for JPG
output. This is why is puzzles me that so many cameras produce
purple-fringed JPGs when the camera ought to be able to remove it.
Panny's do a darned good job of that. (I'd rather look at a little
'noise' than at tree branches swimming in purple fog.)

I have used wider lens than this, I have used other compacts with 24mm, and I didn't expect this either

and let's not forget panasonic always tout about its lens, being "leica", "producing minimal distortion (in it's website advertisement)"...

valid point, automatic correction is effort-saving, but it depends on how much distortion to correct...as I suggested, when it involves so much correction, the intention of panasonic is doubtable.

If I have seen raw file like I have posted, I wouldn't buy the camera.

so panasonic saved me an IQ degrading step ( may I say hide it) to induce me to buy this camera...

panasonic can always automatic correct raw, and in the meantime notify user, I think this looks honesty to me

kernow wrote:

OK, but if you have this camera and shoot in RAW you would have to
correct this distortion anyway, it saves a step. In my LX1 they do
not correct it, and not even in JPEG is it corrected as far as I can
see and that is only 28mm.
--
Oll an gwella,
Jim

http://www.flickr.com/photos/50073525@N00/

[FX07]
[LX1]
[FZ30] * IS/L B-300 * IS/L B-Macro * Minolta No. 0, No. 1 & No. 2 *
Sunpak 383 * Benbo Trekker

hmm...I don't understand this part...let me make my testing procedure clearer, so you could help me to see if there is nay problem?

I intent to calculate roughly how much has been cropped to correct distortion (not detail, just pixels)

I have the raw file converted in Silkpix, with defalut setting, and got jpeg1
I have the same raw file went through DCRAW, got a tiff, and convert it to jepg2

I correct jepg2 in Photoshop CS3, lens correction, to roughly match the correction by default silkpix conversion.
after correction, the whole pic became pincushion like

I cropped the maximum rectangle area after lens correction, and measured it's dimension
the measured dimension is 20% smaller compared with jpeg2

and I concluded panasonic did some interpolation to add back the 20% in silkpix

Conversio wrote:

ch01 wrote:

please read my main post, I'm talking about RAW, which should reveal
the true characteristic of the cam, rather than jpeg. By modifying
RAW, panasonic successfully hide the distortion of the lens, which is
misleading. it is difficult for panasonic to tell the user while
doing correction

and FYI, distortion correction certainly degrades the IQ (detail),
that's why rich people buy expensive lens which are distortion "free"
rather than getting a cheap one then correct is using some software

ch01, if you use RAW and Silkypix you should be careful and try to
correct the distortion before developing the raw. Otherwise you lose
some IQ when Silkypix corrects it by default and correcting it a
little more in Photoshop or equivalent. It's better to do this in a
unique step. It's true Panasonic (or Silkypix proprietary) should
have been clearer with the LX3 support. Distortion correcting values
shouldn't be but it's real value.

BTW I don't know of any wide lens for less than 400$ without barrel
distortion! I think LX3 lens performs very well for its size and its
price. For me, it's only real issue is poor sharpness in distant
objects, but this is a question for another topic in the forum...

I don't know, but the problem is not there is barrel distortion, the problem is there is HUGE barrel distortion, and more seriously, how panasonic handled this information...

Hi, Bo, thanks for advice

actually not many know about the RAW auto proceesing until recently, and if you don't dig into forum like this, u probably will never know.
and it's not an industry standard to manipulate raw like this

Compared with other models, LX3's image is distinctively soft to my eyes, I'm not sure if this could be caused by the excessive distortion correction. But I'm pretty sure removing distortion has a bad effect...

I'm perfectly fine with distortion, I'm not ok with HUGE distortion
I used a number of wide angles, and never saw things like this

and even the distortion of some lens is severe, I still got to know from RAW, so I can make right decision if I will purchase.

but for LX3, I looked the raw sample from my friends in silkpix, thought it was good, and went out to get one. neither of us knew panasonic did the modification, as silkpix suggested lens correction was 0.

even if panasonic could maintain the IQ (not likely, distortion correction is always worse than you directly get it right), the IQ alone doesn't justify panasonic's attitude, by depriving users the rights of getting unmodified data, as what RAW means.

BTW, in panasonic's advertisement, it says the camera produces minimal distortion...

Bo Lorentzen wrote:

CH01,

While you do have a point, its not exactly a secret and I don't think
its reasonable to call Panasonic deceptive.

Besides and more important, the files print great. I have printed
13x19 on my epson and the prints look great. This is what I bought
the camera for and it is delivering what I had hoped.

I have great wideangle lenses, all of which cost significantly more
than this camera, it is simply not reasonable to expect a distortion
free for usd 400.

Go take some pictures and stick them on the wall. Im pretty sure you
will enjoy the results and agree with your self that it really do not
matter how they were captured now that they are on the wall.

Bo

http://www.bophoto.zenfolio.com
http://www.bophoto.com/panos