Picture Distortion: I took this picture the other day on my Nikon7100 using an AF-S Nikkor 18-300mm lens. It was wide open at 18mm. Not a great photo, but it demonstrates a problem...

MaryFran Loc: Front Royal, VA

I took this picture the other day on my Nikon7100 using an AF-S Nikkor 18-300mm lens. It was wide open at 18mm. Not a great photo, but it demonstrates a problem that happens often, but I have not paid much attention to until now. The fence I took the picture through appears to be bowed, but that is not the case in reality. This happens often whenever there is a straight edge in the picture like when I photograph puzzles we have finished.

Is this a problem with the lens or what? Thanks.

BooIsMyCat Loc: Somewhere

MaryFran wrote:

I took this picture the other day on my Nikon7100 using an AF-S Nikkor 18-300mm lens. It was wide open at 18mm. Not a great photo, but it demonstrates a problem that happens often, but I have not paid much attention to until now. The fence I took the picture through appears to be bowed, but that is not the case in reality. This happens often whenever there is a straight edge in the picture like when I photograph puzzles we have finished.

Is this a problem with the lens or what? Thanks.

Have you tried using Lens Correction in LR?

Ysarex Loc: St. Louis

MaryFran wrote:

I took this picture the other day on my Nikon7100 using an AF-S Nikkor 18-300mm lens. It was wide open at 18mm. Not a great photo, but it demonstrates a problem that happens often, but I have not paid much attention to until now. The fence I took the picture through appears to be bowed, but that is not the case in reality. This happens often whenever there is a straight edge in the picture like when I photograph puzzles we have finished.

Is this a problem with the lens or what? Thanks.

To answer your question -- yes, it's the lens. You're seeing what is called barrel distortion. It exaggerates as you move from the center to the sides of the frame. Your camera processing software that creates JPEGs should be attempting to correct and if you process raw files then your raw processing software should also attempt to correct with an option that you can correct manually.

Joe

CHG_CANON Loc: the Windy City

This is an example of “barrel distortion”, when straight lines are curved inwards in a shape of a barrel. This type of aberration is commonly seen on wide angle lenses, barrel distortion happens because the field of view of the lens is much wider than the size of the image sensor and hence it needs to be “squeezed” to fit. As a result, straight lines are visibly curved inwards, especially towards the extreme edges of the frame.

You might visit the support section of the Nikon website and check if a firmware update is available for your D7100. There was a Nikon firmware update a few years ago for all Nikon models that loaded profile corrections for Nikon lenses. If you find a firmware update is available, re-test the camera / lens combo on a similar image after installing the update to your camera. If still not satisfied, consider using a digital editor to 'force' a manual correction to these types of images.

MaryFran Loc: Front Royal, VA

CHG_CANON wrote:

This is an example of “barrel distortion”, when st... (show quote)

Thanks. I will go to the Nikon website later this morning to see what I can find.

It is true that I have usually noticed this on close shots with the lens on 18mm. Now, I am curious to see if that's the only shots I have seen it in.

mwsilvers Loc: Central New Jersey

MaryFran wrote:

I took this picture the other day on my Nikon7100 using an AF-S Nikkor 18-300mm lens. It was wide open at 18mm. Not a great photo, but it demonstrates a problem that happens often, but I have not paid much attention to until now. The fence I took the picture through appears to be bowed, but that is not the case in reality. This happens often whenever there is a straight edge in the picture like when I photograph puzzles we have finished.

Is this a problem with the lens or what? Thanks.

It's called barrel distortion and is quite common in wide-angle lenses and the wide end of zoom lenses. It is usually more noticeable when verticals at the edges of the frame are close. As already indicated it can usually be fixed in post processing.

MaryFran Loc: Front Royal, VA

Ysarex wrote:

To answer your question -- yes, it's the lens. You're seeing what is called barrel distortion. It exaggerates as you move from the center to the sides of the frame. Your camera processing software that creates JPEGs should be attempting to correct and if you process raw files then your raw processing software should also attempt to correct with an option that you can correct manually.

Joe

I only use jpeg. I guess I have no software in the camera to attempt to correct this. Why is the software not there? I will have to ask a friend of mine who previously owned this model camera if she ever had the same problem.

spaceylb Loc: Long Beach, N.Y.

https://www.kenrockwell.com/nikon/18-300mm.htm#dist

MaryFran Loc: Front Royal, VA

BooIsMyCat wrote:

Have you tried using Lens Correction in LR?

Don't know what Lens Correction in LR is.

pendennis

At 18mm, lenses will distort, especially any image that's viewed off-axis. Some lenses are worse than others, but any lens shorter than 24mm focal length will display it to a degree. Once shorter than 20mm, it becomes more exaggerated.

The partial solution is to keep the subject on a parallel plane to the ground. Barrel distortion can be minimized, but not often with a SLR-type camera. To eliminate the phenomenon mostly completely, you need something like a view camera, which allows for camera movements to eliminate a lot of distortion.

As others mentioned, with post-processing software, you can eliminate a lot of the distortion. Affinity, Photo Shop, and others work well. You can also try GIMP.

BooIsMyCat Loc: Somewhere

MaryFran wrote:

Don't know what Lens Correction in LR is.

Lens Corrections is a tool within Lightroom’s Develop Module that allows fixing such lens problems as distortion, chromatic aberration, vignetting, and perspective correction “non-destructively”, without leaving Lightroom.

By your response, I'm thinking you don't use Lightroom (LR)?

Ysarex Loc: St. Louis

MaryFran wrote:

Thanks. I will go to the Nikon website later this morning to see what I can find.

It is true that I have usually noticed this on close shots with the lens on 18mm. Now, I am curious to see if that's the only shots I have seen it in.

If you want to see how your lens really performs take some photos saving raw files and then load those into an editor that will allow you to disengage the auto lens correction (Raw Therapee works). It can be a shocking experience.

Back in the day when we put film in cameras and the final image was recorded on that piece of film the camera manufacturers had to work hard to produce lenses as free of this type of distortion as possible. With the advent of digital and the opportunity to apply software corrections the camera manufacturers quickly made the choice to save $$$ on the lenses and fix it in software. Many modern lenses for digital cameras are in fact worthless trash if you tried to use them on a film camera.

Joe

Ysarex Loc: St. Louis

MaryFran wrote:

I only use jpeg. I guess I have no software in the camera to attempt to correct this. Why is the software not there? I will have to ask a friend of mine who previously owned this model camera if she ever had the same problem.

I think the software is there and it's working. What you're experiencing is a poor job of software correction. I suspect your lens is in fact much worse than what you're seeing in this photo.

Joe

CHG_CANON Loc: the Windy City

MaryFran wrote:

I only use jpeg. I guess I have no software in the camera to attempt to correct this. Why is the software not there? I will have to ask a friend of mine who previously owned this model camera if she ever had the same problem.

This in-camera software correction is the 'firmware', for the JPEGs created / processing internally by the camera. Hopefully, a firmware update is available and will help your specific combo.

MaryFran Loc: Front Royal, VA

CHG_CANON wrote:

This in-camera software correction is the 'firmware', for the JPEGs created / processing internally by the camera. Hopefully, a firmware update is available and will help your specific combo.

I looked on the Nikon website. There is a firmware update available, but I am terrified to try it, just like when I first started using a computer, for fear I will destroy the camera.