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S90 distortion: is the cure worse than the disease?

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Matt F

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I just did my first real outing with the S90, to a Halloween party. I primarily bought the camera to have something pocketable with an F2.0 lens. But of course to get F2.0 you need to be at the widest angle, which means the most barrel distortion.

I am finding that if you take vertical shots of people, and have their heads anywhere near the top edge of the frame the Canon barrel distortion correction stretches them out in a very unflattering way.

Here is a Lightroom conversion of an image that shows this. Barrel distortion is completely uncorrected (though I did a bunch of other corrections to bring the photo more to my liking)...



And here is the way that Canon DPP converts it. Look how his head is elongated in a very unflattering way...



All in all, for these party pictures, the barrel distortion does not bother me at all, but the correction looks terrible in quite a few of my shots.

For now, the solution is easy – I am just converting in Lightroom beta. The colors are not quite as accurate, and the noise is a bit worse, but for these types of shots, I don't care.

What worries me is that when Adobe fully supports the S90, they may make the lens correction built-in, with no option to turn it off (like it is with the LX3). Though maybe they will at least leave access to the the current beta camera conversion, like they still include previous conversion profiles for other cameras, so that old pictures do not suddenly look different?

If you have a facebook account, and want to see the rest of my lightroom conversions from this party, you can see the full set here:
http://www.facebook.com/home.php#/album.php?aid=121915&id=599923422
--
Matt Freedman
http://www.silentcolor.com
http://www.facebook.com/MattFreedmanPhotography
 
people tend to get stretched and distorted with WA lenses anyway ..get out your DSLR and take a portrait of someone at 16mm on a FF or 10mm on a crop. If they do not have a sense of haha they may not be your friend for long ...so in this case yes the cure for the distortion may very well be worse then the illness.. so in that case dont fix want aint broke
 
What bothers me the most is the upsampling of the image to 10MP, which gives the images a soft look.
 
Yes, the barrel distortion correction seems to crop quite a few pixels off the edges, then stretches out and flattens the image to fill them back in, so the corrected edges are not going to look very good.

Though again, as long as we have a choice about whether to do the correction or not, then I have no problem with it. I am just worried that Lightroom is going to cut off access to the uncorrected raw files. I would really hate to have to drop a different converter into my workflow.
Radu P said:
What bothers me the most is the upsampling of the image to 10MP, which gives the images a soft look.
Click to expand...
--
Matt Freedman
http://www.silentcolor.com
http://www.facebook.com/MattFreedmanPhotography
 
Matt F said:
For now, the solution is easy – I am just converting in Lightroom beta. The colors are not quite as accurate, and the noise is a bit worse, but for these types of shots, I don't care.

What worries me is that when Adobe fully supports the S90, they may make the lens correction built-in, with no option to turn it off (like it is with the LX3). Though maybe they will at least leave access to the the current beta camera conversion, like they still include previous conversion profiles for other cameras, so that old pictures do not suddenly look different?
Click to expand...
Thats a good point and one i hadn't thought off. We will have to see what happens i guess.

Did you know that you can enable the luminance NR slider by changing the Process version to 1 in LR3b, this might help with the NR for now. Its on the settings menu.

Just looking through your gallery. That looks like an amazing party and i think the S90 did really well considering. So did you of course.
--
Dave.

Gallery @
http://davepearce.smugmug.com
S90 Shots @
http://www.flickr.com/photos/davebass5/sets/72157622647970370/
Videos @ http://www.vimeo.com/user464364/videos
 
It was definitely a great party. The other big problem I had with the S90, I did not discover until looking at the photos on the computer. Namely, I thought I was shooting at F2.0 all night, but because I had left "Safety FE" (under the Flash Settings sub-menu) left in its default On setting, most of the time the camera did not actually use the aperture and shutter it was telling me it was using. Here is a thread about that...
http://forums.dpreview.com/forums/read.asp?forum=1010&message=33562627
dave_bass5 said:
Just looking through your gallery. That looks like an amazing party and i think the S90 did really well considering. So did you of course.
Click to expand...
--
Matt Freedman
http://www.silentcolor.com
http://www.facebook.com/MattFreedmanPhotography
 
Matt F said:
It was definitely a great party. The other big problem I had with the S90, I did not discover until looking at the photos on the computer. Namely, I thought I was shooting at F2.0 all night, but because I had left "Safety FE" (under the Flash Settings sub-menu) left in its default On setting, most of the time the camera did not actually use the aperture and shutter it was telling me it was using. Here is a thread about that...
http://forums.dpreview.com/forums/read.asp?forum=1010&message=33562627
dave_bass5 said:
Just looking through your gallery. That looks like an amazing party and i think the S90 did really well considering. So did you of course.
Click to expand...
--
Matt Freedman
http://www.silentcolor.com
http://www.facebook.com/MattFreedmanPhotography
Click to expand...
Yeah, i read that thread as it was going on.

As i have a 40D (and 30D before that) im aware of this safety shift and turn it off.
--
Dave.

Gallery @
http://davepearce.smugmug.com
S90 Shots @
http://www.flickr.com/photos/davebass5/sets/72157622647970370/
Videos @ http://www.vimeo.com/user464364/videos
 
I'm wondering if you did something goofy while postprocessing. I took some pictures and cannot seem to replicate what you posted. I am getting the same undistorted image when I compare the out of camera jpeg, raw corrected automatically in DPP, and raw manually adjusted for distortion in photoshop.

Has anybody else seen any remotely this bad coming out of DPP?
 
jasontb said:
I'm wondering if you did something goofy while postprocessing. I took some pictures and cannot seem to replicate what you posted. I am getting the same undistorted image when I compare the out of camera jpeg, raw corrected automatically in DPP, and raw manually adjusted for distortion in photoshop.

Has anybody else seen any remotely this bad coming out of DPP?
Click to expand...
I think it could also be the angle the shot was taken at.

To me it looks like the camera is angled down a bit so this would also cause a bit of distortion.

I must admit i looked at a few shots that i have that are similar and dont really see this problem either although i can understand why its happening.
--
Dave.

Gallery @
http://davepearce.smugmug.com
S90 Shots @
http://www.flickr.com/photos/davebass5/sets/72157622647970370/
Videos @ http://www.vimeo.com/user464364/videos
 
Any rectilinear lens does that, no matter how good it is.

That's why such barrel distortion isn't necessarily a bad thing after all. Don't bother correcting it unless you're shooting architecture. Worst case - use dcraw to convert it.
Matt F said:
I just did my first real outing with the S90, to a Halloween party. I primarily bought the camera to have something pocketable with an F2.0 lens. But of course to get F2.0 you need to be at the widest angle, which means the most barrel distortion.

I am finding that if you take vertical shots of people, and have their heads anywhere near the top edge of the frame the Canon barrel distortion correction stretches them out in a very unflattering way.

Here is a Lightroom conversion of an image that shows this. Barrel distortion is completely uncorrected (though I did a bunch of other corrections to bring the photo more to my liking)...



And here is the way that Canon DPP converts it. Look how his head is elongated in a very unflattering way...



All in all, for these party pictures, the barrel distortion does not bother me at all, but the correction looks terrible in quite a few of my shots.

For now, the solution is easy – I am just converting in Lightroom beta. The colors are not quite as accurate, and the noise is a bit worse, but for these types of shots, I don't care.

What worries me is that when Adobe fully supports the S90, they may make the lens correction built-in, with no option to turn it off (like it is with the LX3). Though maybe they will at least leave access to the the current beta camera conversion, like they still include previous conversion profiles for other cameras, so that old pictures do not suddenly look different?

If you have a facebook account, and want to see the rest of my lightroom conversions from this party, you can see the full set here:
http://www.facebook.com/home.php#/album.php?aid=121915&id=599923422
--
Matt Freedman
http://www.silentcolor.com
http://www.facebook.com/MattFreedmanPhotography
Click to expand...
--

. 。o O o 。 . 。o O o 。 . 。o O o 。 .
 
First, this is most visible when the lens is at its widest angle position. There is much less distortion as you zoom in.

The out of camera jpeg will definitely look the same as what comes out of DPP, as they will both silently apply the same correction of barrel distortion.

I have not tried opening an image in Photoshop, but it should be using the same beta camera profile as Lightroom, so the barrel distortion correction should not be getting applied. You are sure you are opening the raw image in photoshop, i.e. getting the Adobe Camera Raw adjustment interface? Not opening a DPP produced tiff or jpeg in Photoshop?
jasontb said:
I'm wondering if you did something goofy while postprocessing. I took some pictures and cannot seem to replicate what you posted. I am getting the same undistorted image when I compare the out of camera jpeg, raw corrected automatically in DPP, and raw manually adjusted for distortion in photoshop.

Has anybody else seen any remotely this bad coming out of DPP?
Click to expand...
--
Matt Freedman
http://www.silentcolor.com
http://www.facebook.com/MattFreedmanPhotography
 
I took a photo at full wide of graph paper. And compared:

1) jpeg from camera
2) DPP converted raw
3) open raw in lightroom, export to PS for barrel correction

My squares were square in each version. Maybe I missed something. My squares were not square however when I opened the raw in lightroom and had not made any distortion adjustments yet.

I am going to monkey around some more tonight when I get home because I didn't spend much time on it yesterday and maybe I goofed something up. Or maybe somebody sees some flaw in what I did.

Matt, can you post the image uncropped without distortion correction?
Matt F said:
First, this is most visible when the lens is at its widest angle position. There is much less distortion as you zoom in.

The out of camera jpeg will definitely look the same as what comes out of DPP, as they will both silently apply the same correction of barrel distortion.

I have not tried opening an image in Photoshop, but it should be using the same beta camera profile as Lightroom, so the barrel distortion correction should not be getting applied. You are sure you are opening the raw image in photoshop, i.e. getting the Adobe Camera Raw adjustment interface? Not opening a DPP produced tiff or jpeg in Photoshop?

--
Matt Freedman
http://www.silentcolor.com
http://www.facebook.com/MattFreedmanPhotography
Click to expand...
 
Ahh -- you are doing barrel distortion correction in Photoshop, that is why all three of your final images look the same. What I am saying is that barrel distortion correction will elongate things at the edges of the frame, and sometimes (like if it is somebody's head) that will look bad.

I am just converting in Lightroom, which does not do any barrel distortion correction (at least in the current beta version of S90 support). So heads near the edge of the frame look much better, but if I had graph paper in the shot the squares would not be square.

Neither image in my original post is cropped at all vertically (my Lightroom conversion is cropped horizontally to bring it to 3:2). Which points out another issue with barrel distortion correction – it also causes you to lose pixels at the edges of your image.

The bottom line is that sometimes barrel distortion correction is what you will want, i.e. if you are shooting buildings (or graph paper). But other times it hurts more than it helps (close up vertical party pictures, especially when there is a head near the top of the frame).

So hopefully when Lightroom adds the distortion correction there will be an option to use it or not. But I am concerned, because apparently with the LX3, you are forced to use it.
jasontb said:
I took a photo at full wide of graph paper. And compared:

1) jpeg from camera
2) DPP converted raw
3) open raw in lightroom, export to PS for barrel correction

My squares were square in each version. Maybe I missed something. My squares were not square however when I opened the raw in lightroom and had not made any distortion adjustments yet.

I am going to monkey around some more tonight when I get home because I didn't spend much time on it yesterday and maybe I goofed something up. Or maybe somebody sees some flaw in what I did.

Matt, can you post the image uncropped without distortion correction?
Click to expand...
--
Matt Freedman
http://www.silentcolor.com
http://www.facebook.com/MattFreedmanPhotography
 
Back to the original post:

"Look how his head is elongated in a very unflattering way... "

There's a guy in that picture..?

Sorry - had to say it.

I actually wish that Canon would give you the option of turning the correction on or off. There are times when having a quasi-fisheye look would be a cool free extra to have access to.
 
Matt F said:
Ahh -- you are doing barrel distortion correction in Photoshop, that is why all three of your final images look the same. What I am saying is that barrel distortion correction will elongate things at the edges of the frame, and sometimes (like if it is somebody's head) that will look bad.
Click to expand...
Yes I corrected in Photoshop. But I did observe the photo in LR first. The squares on my graph paper were all out of wack. After correction, they were squares again. So I would image that in your photo, guys head is out of whack then you view it in LR without correction. After distortion correction in PS, the guys head looks normal. I don't understand why barrel correction 'fixes' the shape of my squares, but 'destroys' your shape of your man's head. Can you explain what I'm missing?
Matt F said:
I am just converting in Lightroom, which does not do any barrel distortion correction (at least in the current beta version of S90 support). So heads near the edge of the frame look much better, but if I had graph paper in the shot the squares would not be square.

Neither image in my original post is cropped at all vertically (my Lightroom conversion is cropped horizontally to bring it to 3:2). Which points out another issue with barrel distortion correction – it also causes you to lose pixels at the edges of your image.
Click to expand...
I understand about losing pixels, but this is what we must live with given size, cost, weight, etc. optimization of the lens and camera chosen by Canon (and appearantly others as well), or so I hear.
Matt F said:
The bottom line is that sometimes barrel distortion correction is what you will want, i.e. if you are shooting buildings (or graph paper). But other times it hurts more than it helps (close up vertical party pictures, especially when there is a head near the top of the frame).

So hopefully when Lightroom adds the distortion correction there will be an option to use it or not. But I am concerned, because apparently with the LX3, you are forced to use it.
Click to expand...
Agreed! Hopefully they don't do what i have heard the camera does (correct barrel, crop, upsize ). That's something else I am going to try to figure out tonight as well...
 
Matt F said:
What worries me is that when Adobe fully supports the S90, they may make the lens correction built-in, with no option to turn it off (like it is with the LX3). Though maybe they will at least leave access to the the current beta camera conversion, like they still include previous conversion profiles for other cameras, so that old pictures do not suddenly look different?
Click to expand...
As I feared, the Lightroom 2.6 release candidate is now available, and it corrects the barrel distortion, with no option to turn it off.

There are 6 calibrations available for the camera now, and the original beta calibration is gone. This means that any S90 images that you previously converted in LR are now going to look radically different, both in color/tone curve (because a different profile will be applied) and because the barrel distortion will be traded for the edge distortion that the correction creates.

If you go back to LR 2.5 after installing 2.6 RC 1 though, the new profiles show up (and the beta is still there).
--
Matt Freedman
http://www.silentcolor.com
http://www.facebook.com/MattFreedmanPhotography
 
I compared conversions done in LR3 beta and LR 2.6, using a sample raw file available on the photography blog website here (the one of the bottle) http://www.photographyblog.com/reviews/canon_powershot_s90_review/sample_images/

I noticed with the 2.6 conversion that apart from losing a considerable amount of the image at the periphery, the whole of the image appears softer, and the colour doesn't seem as subtle in terms of tonality. I was all for software correction of barrel distortion until I saw how much is applied to S90 files, I think Canon should alter the spec to say you are actually buying an 8.5mp camera! ;)
 
Anyone notice that lens correction is NOT getting applied during import in LR3 Beta? It's clearly corrected during the import panel preview, but when it's imported, it's not applied. Is there a setting for this? I've got LR2 installed and LR3 Beta 1 on a Mac running Snow Leopard.

-Dan
 
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