Jagged wires.

[Marc Wilson]

Hi everyone,

I have produced quite a few stock shots that contained wires or cables in the sky over the last few years, cable car cables, power lines, etc, etc.
The ones I shot yesterday I have noticed for the first time that some parts of the wires at certain angles looking jagged in the digital raw file.(see first wires image)
Other parts of the wires are perfect with no jagged edges at all so its all about the angle they are at. (see second wires image from another section of the same file)
The attached images are of course jpegs from the raw processed tiffs but were processed with no sharpening and so the jaggedness is the same in the raw file.
Shot as I ever do with a 5d at lowest iso and using of course raw, (with my zeiss contax N 24-95mm lens) these lines are in the raw files so are not in the processing.
Is this simply a case of that's what you get sometimes when far off cables are at a particular angle with this type of sensor / resolution, etc or could something else be causing it?

Marc

 

[mark1958]

HI Marc.. May i ask how you convered the RAW images? I notice that some items like wires have these jaggies that come out with little sharpening so perhaps they are there without. I see less of a problem when i use DPP compared with CS3. Mark

 

[Marc Wilson]

Converted with C1 v4
The jagged areas are there pre processing and are certainly less so when I turn sharpening off completely in the raw conversion.
I've just tried to process the same file in DPP and the jaggies show up less but the whole file is softer.(see attached picture).
So, in C1 and DPP, with sharpening set at zero in both, the C1 file comes out a touch sharper. This file can then be softened slightly to lose the jaggies to the same extent as the DPP processed file, but then I lose sharpness in the whole image!

This is what I am doing but trying to soften the affected areas selctively from the C1 processed files...the best all round solution for me.

As an aside apolgies to Tom and anyone else for my typing error, I meant of course 24-85mm!

Perhaps I should have posted this in the image processing section...can it be moved?
Marc

 

[Jack]

Hi Marc:

I see it pretty regularly. If you think about it, a single pixel is square, so the best an angled line can be rendered digitally is as a jagged collection of square corners, assuming optimal processing. Moreover, I've noticed it more frequently when using my best lenses. The good news is a good printer RIP is usually smart enough to know it's supposed to be a line and will smooth it back out

PS: I will move the entire thread into the processing section for you.

Cheers

 

[Marc Wilson]

Cheers Jack,

I wonder would the affect then be the same if the image had been shot on film and then high res scanned?
And again would it be the same or less or more apparent with a higher resolution sensor (mf) or a non AA sensor (M8)?

These images are for stock so should be acceptable with my added selected softening for the library.

Marc

 

[workingcamera]

....I wonder would the affect then be the same if the image had been shot on film and then high res scanned?

Yep… I’ve encountered similar in my scans from 35mm … using the Nikon Coolscan 4000 which I ‘spose is high enough res

Sometimes power lines appear as if they’ve twisted like a ribbon

 

[Jack]

Cheers Jack,

And again would it be the same or less or more apparent with a higher resolution sensor (mf) or a non AA sensor (M8)?

It shows up more on my M8 files than my 5D files, but that could simply be due to better glass. It also showed up with my Betterlight Scanning back, also no AA and high resolution sensor and excellent glass. In both cases, printing though A RIP or printing program like Q-Image attenuates it to the point you can't see it in a print. By contrast, printing the same print directly though the Epson driver did show it on my 7800, though the driver for the 3800 seems to be better --- just need to print them and see.

Cheers,

 

[Paul2660]

Like Jack mentioned, with a square pixel, you will always see some jagged effect. However the AA filter on most cameras should reduce some of this since they are designed to blur the overall image. I would assume that on a Pro back like the P45+, with no AA filter, you are going to see it a good bit.

Any type of liner object that isn't totally straight to the frame would have this problem. Bridges, lines, cables etc.

Paul Caldwell