Distortion Question on RPP...Need Help

[Ryan Gibb]

Hello,

I'm really trying to understand distortion (and especially barrel distortion) when it comes to lenses. For the 25mm RPP, red says that the lens has a Max Distortion of 4%, now is that 4% calculated the same as a canon lens on photozone? Like the link below?

http://www.photozone.de/canon_eos_ff...4mk2ff?start=1

Or does the 4% Red is reporting related to something different? Just a little confused here as 4% seems quite high compared to the 1.4% of the canon lens. If this is not the case does anyone know what the RPP's come in at for distortion or do they calculate totally different with cine lenses and you can't really compare? Just a lot of questions and need help. Thanks in advance.

[Mike Harrington]

that should be the same distortion value's....
will vary alot from lens to lens...as you see the 100mm RPP is 0.6%....

there are a lot of factors to a good lens...the canon you mentioned happens to have very low distortion for its focal range....very low
the 24mm leica summilux is 2.2% distortion....
the 50mm leica summilux.....0.4%

[Ryan Gibb]

Ya Mike,

I guess Canon is known for their low distortion, on their 14mm they have a distortion value of 1.7% I know a lot more goes into making a good lens as things such as bokeh, sharpness, etc. But I am interested in doing some architecture shooting and just trying to figure out what lens works best with my budget. If anyonne can confirm that would be great. Thanks

[ericyoung]

If you shoot a grid with the lens you can always correct for barrel distortion in post.

[Björn Benckert]

agree with eric.
Even though it will bring on some softness it will a lot of times be less softness than shooting with a lens that has les distortion since those lenses usually are softer to start with. There is a lot of good lens correction tools out there. if you shoot a grid or use your architect building edges and "de lens" the footage it will look as good as anything with the RPP's.

[Ryan Gibb]

Thanks Guys, that makes a lot of sense to me. Cheers, Ryan.