PattyW60 Loc: Northwest Illinois

I recently bought my first full-frame dslr, and got a deal I couldn't refuse on a Canon 24-70 f/2.8L lens. I love the camera and lens, but I've never experienced lens distortion like this before. I went out to take some pictures of shelf clouds as a storm was approaching, and I shot most of them at 24mm. When I looked at them later, I was really surprised by the distortion, particularly noticeable because of the telephone pole bowing in. I have a 24-105L lens that I have used on my Canon 7dmkii, but never experienced distortion at 24mm like this. I'm wondering, is this due to one camera being FF vs. crop sensor? So, my bigger questions are, Is this normal? If so, how do I improve my technique/approach to taking pictures at 24mm? I'm new to post-processing images, so if distortion will always be an issue at 24mm, is there something in Photoshop that will fix that? I've attached one of the photos, in case that will be helpful to see what I'm describing. I sure appreciate any help or advise you can share. Thank you! Patty

(Download)

Haydon

It's mostly because of it being at 24 mm on the full frame. Applying a lens profile in post can help this a little or in camera. FWIW, the 24-70 2.8L II handles distortion better than the 24-105 L version 1 & 2 at the wide end but anything outside of the center of the frame will be noticed in either case when using a full frame.

The ideal situation is to use a longer focal length and make a series of shots into a panorama if you want to reduce the distortion signficantly.

Sirsnapalot Loc: Hammond, Louisiana

Correct fisheye effect
https://youtu.be/U2606D0XjXo

rodpark2 Loc: Dallas, Tx

The way to avoid wide angle perspective distortion is to keep the camera level. Any lens, but especially noticeable the wider the lens, will do what you saw when the camera is not level. Tilt-shift lenses are made to deal with the issue.

PattyW60 Loc: Northwest Illinois

Thank you, Haydon! I will check the lens profile, as you suggested. If I had a tripod, it would've been ideal to do a series of vertical shots at a longer focal length and make a panorama. I actually tried doing that handheld, but they didn't stitch together very well in Ps. I'm sure I didn't do something right!! haha

PattyW60 Loc: Northwest Illinois

Thank you, Sir!

PattyW60 Loc: Northwest Illinois

Thank you, Rod. I'll be mindful of keeping my camera level; good point! The field in front of me slopes right to left, and the clouds had their own line going on; fighting with what "felt" level. haha

CHG_CANON Loc: the Windy City

Hey Patty, you didn't mention version numbers, so are these the "v I" versions of the 24-70L and 24-105L lenses, or could one or both be the vII. Also, the 24-70 lens comes in both the f/2.8 and f/4 IS versions. It's not that important to have the specific models other than to recognize each lens model and version of the lens has slightly different characteristics regarding distortion. From my own experience, the original 24-105, aka vI, has a good deal of distortion at 24mm. I've had a lot less 24mm distortion from the 24-70 f/2.8L II, but not non-existent.

To your several questions, yes there is a difference in what you will observe in terms of distortion when using the same lens on FF and cropped bodies. Things you can do to avoid distortion when shooting are to attempt to have the sensor / camera held parallel and level to the subject. This isn't always practical such as shooting upward at buildings in the sky while standing at their base. But, in some situations, you might have an opportunity to maybe take a step back or two or maybe hold the camera slightly higher for more straight-on rather than angled view of the subject.

Actions you can take in post include:

a) Check your EOS camera manual for instructions on how to enable Lens Peripheral Illumination. You may need to download profiles as Canon doesn't ship the cameras with every EF lens and profile enabled.

b) Test you results for both JPEG and CR2, as applicable. I believe the distortion correction will be evident in the JPEGs vs the straight out of camera CR2s (RAW).

c) For RAW, if you have the Canon DPP4 software installed, you can import the CR2 and enable the "digital lens optimizer" and see the distortion corrections Canon will apply for the lens and image. See your EOS camera manual for details in downloading Canon lens profiles to this software, if needed. The results in DPP4 for distortion correction should replicate the in-camera adjustments made to the JPEG

d) In Lightroom, if applicable, you can apply Adobe's versions of the lens corrections with the RAW file imported and opened for edit in the Develop Module. Expand the section 'Lens Corrections' where LR should automatically detect the camera and lens type. You just need to enable the two corrective actions (Chromatic Aberration and Profile Corrections).

e) In Photoshop and / or ARC, again the Adobe lens profiles should be available to apply to your images (but I have less experience here on the 'how')

The various software editing tools (DPPv4, LR, PS/ARC) all have sliders that let your customize the application of the lens corrections. Using the JPEG (w/ corrections enabled) as the 'baseline' you can do some comparative work of the defaults of each software and adjustments, if needed, to your individual needs.

PattyW60 Loc: Northwest Illinois

Paul, thank you for all of this valuable information!! I really appreciate the time it took you to write all of this down!! I will work on those lens profiles. As for the lenses, I have the 24-105 version I, and the 24-70 f/2.8L II. I think I'm just not used to the effects of the wider angle on the FF. Thanks for the advice on both my technique and post-processing! I appreciate it!
Patty

uhaas2009

Just for info, every lens have distortion, doesn’t matter if it is at70mm, 200mm, 14mm. I turned on the life view and till and shift on door frame. Cell phone is good exercise, too.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Patty, there is a little field curvature (uncorrected barrel distortion, together with keystone effect (keystoning - where verticals converge). The first can be mitigated by using a lens profile in post processing software, or manually correcting it in software, or shooting jpeg and letting the camera automatically apply the correct profile.

The second problem is the converging verticals. You can keep the camera level - and just crop the top and bottom of the image to give you the composition you are looking for. Or you can shoot it as you did, and apply the necessary adjustments in post processing - or you can use a shift type lens which lets you raise the lens without needing to tilt the camera up much if at all. Correcting in software might be easier and faster, but you will lose image width and end up with fewer pixels.

Sirsnapalot Loc: Hammond, Louisiana

👍🏼

PattyW60 Loc: Northwest Illinois

Thank you, Gene! I'm only shooting in RAW right now. I'll switch to both Raw and jpeg, so I can see how that works. I'll also be working on the post processing tips. I appreciate the help/advice! Thanks!!
Patty

PattyW60 Loc: Northwest Illinois

Thanks, uhaas.

Architect1776 Loc: In my mind

Your distortion appears to be from pointing the camera up.
PS can easily correct this and make the silo and pole vertical.
Did this in PSE in about 5 seconds.
Not perfect I am sure but gives you an idea of a quick fix easily done.

(Download)