Barrel Distortion

[Ninja1283]

Which version of Photoshop are you using?

I have the CS4 suite, so I cannot access barrel distortion corrections direct from ACR 5.7. (I think the newer 6.1-6.2 versions of ACRthat allow barrel distortion correctionsrequire CS5.) Seems like the ideal solution, but PT lens has a nice PS filter plug in that works well if I stay in Photoshop.

If you're going to be opening into Photoshop anyways why not just export/save it as a jpeg from there?

I tried, but the TIFFs I usually work with from DPP are too big to directly save as a JPG for some reason.





I'm new to all this, and probably sound like an idiot, but thanks for the help so far.

[neuroanatomist]

Personally, I find DxO to be the best RAW converter. It

[neuroanatomist]

Ps. In the recent 15-85 vs. 18-200 thread, barrel distortion came up as well. I posted a DxO-corrected vs. uncorrected image there. I had planned to take a shot with the 24-105mm at 24mm (lots of barrel distortion there), vs. the TS-E 24mm (no distortion) of the same scene. This might be a better thread to post that...

[Ninja1283]

Personally, I find DxO to be the best RAW converter. It's corrections for distortion and noise are better than DPP, and unlike ACR the corrections are based on quantitative testing of each specific camera+lens combo. Specifically for barrel distortion, DxO resulted in better correction and sharper corners in the corrected areas (posting from my iPhone so search doesn't work, but search for "mini bake-off" for my DPP vs. DxO comparison).

I'll have to give that article a read. I looked into DxO before, but couldn't justify the purchase at the time. Always thought it was more expensive, but I guess I must have been looking at the pro body elite version or something...

[Fast Glass]

helpI use DXO and like Neuro said it's the best RAW converter out there. I shoot lot of high ISO images and DXO isextremely helpfulfor that.


John.

[neuroanatomist]

Here are some test images showing barrel distortion and corrections. I had done something similar [url="/photography_tips_techniques1/f/13/t/5120.aspx]previously[/url], but in that case there was both barrel distortion and perspective distortion in the mix. IN this comparison, there's only barrel distortion. Apologies for the lack of inspiration in subject matter - I wanted to find something more interesting than this classic approach to showing barrel distortion, but I had limited time this morning as the snowflakes were starting to fall (silly me, I [i]thought[/i] it was the first day of spring...).


Images were shot on a 5DII with the 24-105mm f/4<span style="color: #ff0000;"]L IS, except for the bottom right image shot with a TS-E 24mm f/3.5<span style="color: #ff0000;"]L II. Both DPP and DxO do a good job correcting the barrel distortion of the zoom lens. DPP crops the corrected image a little bit tighter than DxO, such that the centers of the edges are the same in the uncorrected and DxO images. Interestingly, 24mm on the 24-105mm is a little bit wider than the 24mm TS-E framing. Click image for a larger view.

[HDNitehawk]

John


TS-E shot dead center with no tilt or correction right?

[neuroanatomist]

Correct - no tilt or shift, and I had a bubble level in the hotshoe.

[Mark Elberson]

Nice job John. I am honestly shocked by how bad that really is!


While you were shooting these did you take any with the lens tilting up? I'd be curious to see how much that statue would start to lean if you did. I bet at that point you'd really hear people complaining about the "barrel" distortion [:P]