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15mm shots with EF-S 15-85mm lens.

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Damoo

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Hi,

I have been using the 15-85mm lens with my new EOS 7D. When shot at 15 or 16mm, the edges were not very sharp. Before purchasing the lens I know that distortions around the edges are natural for a wide angle lens.Yesterday I tried shooting a building & found there was lot of distortion. I dont know if its really the expected distorion or if I missed some technique. Any feedback wud be of great help...

Pic shot at 16mm f11 @1/60 sec with IS on.

Tks



 
where was the focus point?
--
Photography, It ain't the same old Art form it used to be..
 
Seems quite acceptable to me. The image is underexposed but aside from that, that is what I would expect from almost any wide angle lens from that perspective.

If this was my shot, I would shoot it in raw and in lightroom I would adjust the distortion and bring the building back to vertical at the cost of losing some sky and width at the base. Photoshop could also take out the distortion.

The only lens that will provide you with "acceptable right from the lens" would be a tilt shift lens.

Nothing wrong here!
 
If you could photograph the building from halfway up you would at least have a symmetrical amount of distortion... :)

Wide angle lens naturally do have this type of optical distortion. The lens elements required to give you such a wide angle come at a tradeoff cost of distortion.

I haven't been successfully able to use Canon's DPP lens distortion adjust to correct for this. A PP tool like photoshop can easily 'fix' it. When photographing, keep the PP in mind so that you give ample space on the sides to allow for what will be lost when it is corrected.
Damoo said:
Hi,

I have been using the 15-85mm lens with my new EOS 7D. When shot at 15 or 16mm, the edges were not very sharp. Before purchasing the lens I know that distortions around the edges are natural for a wide angle lens.Yesterday I tried shooting a building & found there was lot of distortion. I dont know if its really the expected distorion or if I missed some technique. Any feedback wud be of great help...
Click to expand...
 
It was auto select.
 
I am not knowledgeable enough to categorize it. Probably its the barrel distortion thats common with wide angle lens. For landscape photos I normally crop the ends which appear distorted. But in this pic I felt it was too much. :( Almost 4-5 shots around 15/16mm appear the same way.
 
Thank U very much. I wud keep in mind your suggestion when I shoot with this lens henceforth.
 
Thank U. I shot it in RAW. Then for the purpose of uploading it here, just converted it to .jpeg without any other processing just as it is. Tks a lot.
 
Like others, I'm a bit confused as to what form of distortion you're referring to. The barrel distortion (slight bulging at the edges) can be eliminated if you shot in RAW using ACR, either in Photoshop or Lightroom, by clicking on Lens Profile Correction. If you want to straighten out the edges of the building and eliminate the keystoning, there's a way to do that in Photoshop as well. While you're at it, again if shot in RAW, you can also tweak the exposure a bit and with those changes you'd probably be able to get the results you're looking for.
Damoo said:
Hi,

I have been using the 15-85mm lens with my new EOS 7D. When shot at 15 or 16mm, the edges were not very sharp. Before purchasing the lens I know that distortions around the edges are natural for a wide angle lens.Yesterday I tried shooting a building & found there was lot of distortion. I dont know if its really the expected distorion or if I missed some technique. Any feedback wud be of great help...

Pic shot at 16mm f11 @1/60 sec with IS on.

Tks



Click to expand...
 
Jerry-astro said:
Like others, I'm a bit confused as to what form of distortion you're referring to. The barrel distortion (slight bulging at the edges) can be eliminated if you shot in RAW using ACR, either in Photoshop or Lightroom, by clicking on Lens Profile Correction. If you want to straighten out the edges of the building and eliminate the keystoning, there's a way to do that in Photoshop as well. While you're at it, again if shot in RAW, you can also tweak the exposure a bit and with those changes you'd probably be able to get the results you're looking for.
Click to expand...
I agree. This 15-85 is my only lens right now on my 7D, and I love it ... after I fix the lens distortions in Adobe Lightroom. The OP should look for online deals (I got one at saveintheusa.com) and get a copy. It is fast and gives great results.

DxO Optics Pro is on sale for $99 until July 15. I find it clunky to use (very slow onscreen updates), and the default results not to my liking (yuck for the over-agressive noise reduction). But, it does everything, including distortion correction, and I'm sure it is tweekable to get good results.

Both programs have 30-day downloadable full-version trials, though I would greatly recommend Lightroom over DxO.
 
photoPhlow said:
DxO Optics Pro is on sale for $99 until July 15. I find it clunky to use (very slow onscreen updates), and the default results not to my liking (yuck for the over-agressive noise reduction). But, it does everything, including distortion correction, and I'm sure it is tweekable to get good results.
Click to expand...
Yes. The defaults are very easy to change. The first thing I did was to turn the NR off as a default setting. The other controls are very powerful.
 
Damoo said:
I have been using the 15-85mm lens with my new EOS 7D. When shot at 15 or 16mm, the edges were not very sharp. Before purchasing the lens I know that distortions around the edges are natural for a wide angle lens.Yesterday I tried shooting a building & found there was lot of distortion.
Click to expand...
If you want a lens with low distortion, take the large number on the zoom, divide it by the little number on the zoom, and look for a quotient less than 3.

Thus 85/15 = 5.66 > 3.0 -> has anoying distortion
Thus 70/24 = 2.91 has little distortion
--
Mitch
 
MitchAlsup said:
If you want a lens with low distortion, take the large number on the zoom, divide it by the little number on the zoom, and look for a quotient less than 3.

Thus 85/15 = 5.66 > 3.0 -> has anoying distortion
Thus 70/24 = 2.91 has little distortion
--
Mitch
Click to expand...
2.91 is "little distortion"? You gotta be kidding...? Anything over 1% is easily visible if there are straight lines along the image edges (like e.g. the horizon).
--
  • Jan
 
lens distortion is a natural event as in your never going to make it go away unless your using a tilt/shift lens(which Canon makes 3 of them). On a crop body like the 7D, 60D, and so on distortion is a little less than on a full frame body depending on the lens used. Your image looks pretty good for 15mm how ever your 15mm turns into a 24mm lens on the 7D which isn't super wide. Canon does make a 24mm TS-E tilt/shift and its a killer lens.
--
AustinLuker.com
7D-5DMKII-1DMKIV
 
You might try backing up . The less angle of camera to subject the better . I try to keep the 10-22 level and square , then crop .
--
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Austin_Luker said:
lens distortion is a natural event as in your never going to make it go away unless your using a tilt/shift lens(which Canon makes 3 of them). On a crop body like the 7D, 60D, and so on distortion is a little less than on a full frame body depending on the lens used. Your image looks pretty good for 15mm how ever your 15mm turns into a 24mm lens on the 7D which isn't super wide. Canon does make a 24mm TS-E tilt/shift and its a killer lens.
--
AustinLuker.com
7D-5DMKII-1DMKIV
Click to expand...
You are mixing up geometrical distortion and optical distortion. Geometrical distortion is the slanting of the building outlines when looking up, and can indeed be corrected using a shift lens, or on the computer. Optical distortion, as was discussed in the two previous posts, is an optical fault in the lens, which makes straight lines away from center appear curved, either inwards or outwards, or both (moustache distortion). Most lenses have some optical distortion, zooms have the most, and macro lenses usually almost none. Fisheyes have intentional optical distortion.

--
  • Jan
 
Damoo said:
It was auto select.
Click to expand...
If you had the focus point set to 'auto select' then all bets are off. If you don't know where the focus point was, your original question is invalid. Nobody can make a judgement without knowing where you focused. If you open the image in a program that shows the active focus point (assuming you did NOT focus and recompose) then you can at least get an idea of what is going on.

The image looks fine to me under the circumstances.

--
Photoblog at: http://timrucciphotography.blogspot.com/
Gallery at: http://www.timrucci.com

 
OP: what's your question? You said two things: Blurry and Distortion. I see both. Distortion (the lines of the building aren't quite straight) is normal for the 15-85 zoomed out like you have it.
However, the lack of sharpness (blurry) shouldn't be a problem at all.

BUT: you need to provide more pics.
Set the camera to AV and set the aperture to 3.5 when zoomed to 15mm.
Then post some crops of the middle and corners.

I had a 15-85mm that was a bad sample:
http://forums.dpreview.com/forums/readflat.asp?forum=1029&message=38811438

But, the key is taking 100% crops from different parts of the frame.

-david
 
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