XT CA examples. (24mm f2.8)

[dxphoto]

Hi, sorry that I am starting a new thread regarding the same topic <a

href="http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00H6Ub&tag=">Chromatic

Aberrations of EF 24mm, because of digital?</a> I posted two days ago. <br><br>

 

Here is the example <br><br>

this is the original <br>

<img src="http://www.bluecosmosstudio.com/share/temp/orginal2.jpg"><br><br>

 

the 100% crop of the lower right corner.<br>

<img src="http://www.bluecosmosstudio.com/share/temp/crop2.jpg"><br><br>

 

Is it normal or I am just being too picky. <br><br>

It is shot with an XT + 24mm f2.8 lens. f10, 1/25s (quite slow i know).

Handheld. UV filter.<br><br>

 

Thanks.<br><br>

[dxphoto]

Sorry forgot, the ISO setting is 400. Thanks again.

[eugene_scherba]

Hey, my Sigma zoom (18-50 2.8 EX) does the same if not worse, and

I'm not complaining.

[bobatkins]

You're being too picky!

[gdanmitchell]

Too picky! :-) Photoshop will clean that up in a jiffy.

[kevin conville]

Looks pretty minor to me.

[PuppyDigs]

Something's odd about that image. Its a bit overexposed (blacks are too grayish) and the

contrast is seriously low and washed out looking. Also, I see a serious amount of flare--e.g.,

a reflection of the diaphragm on the dogtag. Finally the whites are too magenta.

[neil_herke]

"Too picky! :-) Photoshop will clean that up in a jiffy."

 

Hi dan, what would you say was the best way to clean it up in photoshop? and how about removing more pronounced purple fringing?

 

Cheers

[gdanmitchell]

"Hi dan, what would you say was the best way to clean it up in photoshop? and how about

removing more pronounced purple fringing?"

 

Sure, but with a clarification. To be more accurate I should have written that you could

clean it up in Bridge. I shoot RAW and use Bridge (part of the current Photoshop package)

to convert from RAW to Photoshop.

 

During conversion Bridge brings up a window where you can set parameters for the

conversion. Zoom in to at least 100% manification in Bridge; I often work at 200%

magnification or sometimes even a bit higher so that the CA will be more visible.

 

Click on the "Lens" tab and look for the "Chromatic Abberation" section where

you can adjust for CA. I often need to set the upper number to a negative value, which

may

vary between perhaps -15 and -50

depending upon what lens I used.

 

There may be a way to do this directly in Photoshop after conversion, but I'm afraid I can't

point you to it since I use Bridge for this purpose in my workflow.

 

In my experience, the CA adjustment during RAW conversion is generally very effective

with all of my lenses.

 

Good luck!

[gdanmitchell]

Following up on my previous message...

 

Writing the description from memory, I now realize that my description was not exactly

accurate. I think it is fair to say that I conflated three applications: Bridge, Adobe RAW

Converter, and Photoshop. Let me clarify.

 

I begin by browsing my RAW images in Adobe Bridge. When I find one that I want to work

on I double-click it. This opens the image in...

 

... the Adobe RAW Converter window. This is the window I was mainly describing in my

previous window - the one that includes the "Lens" tab providing control over CA. (I

mistakenly implied that this was part of the Bridge program.) Once I finish my

adjustments, including fixing and CA, in the Adobe Raw Converter window, I click the

"Open" button and...

 

... the image opens in the regular Photoshop environment.

 

Dan

[neil_herke]

I dont actually have bridge installed. I have been using either DPP but i have just got a mac so been using the beta version of lightroom (which i love!)

 

I'll find my copy of CS and reinstall everything again.

Thanks for the help

Neil

[steve_dunn2]

<p>Yup, you're too picky. At various focal lengths, my 17-40/4L USM and 28-135/3.5-5.6 IS USM both produce far worse CA than that. I only have PS Elements, which doesn't allow CA correction during RAW conversion, so I use PTLens to fix CA.</p>