XF 35mm 1.4R CA

[3dit0r]

Just wondered if a good deal of CA is standard issue on the 35 1.4 wide open? I just got my copy yesterday and it's pretty bad, and not just at the edges of the frame, right across the frame wide open with highlights.

Cheers,

James

 

[f16sunshine]

Just wondered if a good deal of CA is standard issue on the 35 1.4 wide open? I just got my copy yesterday and it's pretty bad, and not just at the edges of the frame, right across the frame wide open with highlights.

Cheers,

James

Sounds like you have an issue with the lens. I have not seen much signs of C.A. with this lens.

 

[coelacanth]

From my limited time of use, I haven't really noticed that. Wanna post a few pics?

 

[3dit0r]

From my limited time of use, I haven't really noticed that. Wanna post a few pics?

Sure I'll post some up tomorrow, I have to pop out in a moment.

I did just test very quickly using my Sony NEX-6/35mm 1.8 wide open and I guess it's comparable overall. Maybe a little worse on the Fuji, but then it's at 1.4, not 1.8, so maybe it's just normal.

 

[semilog]

Also: CA is one of the easier aberrations to correct in post.

 

[willie_901]

Are the photographs in question out of camera JPEGs? If they are raw, what program was used to render the images?

Are you concerned with lateral or longitudinal CA?

Some lens test results are here:

"http://www.photozone.de/fuji_x/746-fuji35f14?start=1"

and here

http://www.slrgear.com/reviews/showproduct.php/product/1487/cat/105

 

[3dit0r]

Couldn't work out how to upload so here's a flickr link. Don't know why photoshop can't down-res without aliasing, but there you go.

http://flic.kr/p/mgLvus

This is a jpeg straight from camera, the raw file shows the same CA when I tried opening in Camera Raw RC, although it attempts to apply an automatic, undefeatable lens profile.

By the way, it's totally accidental, as this is just a horrid snap of the crap and detritus at the end of my kitchen table, but it happens the purple coat behind makes it very difficult to remove purple fringing.

It's not easy to remove CA when Lightroom doesn't support the X-T1 yet... 😉

P.S. The fringing is mitigated by f/2 and largely gone by f/2.8. Nonexistant at f/4. The reason this shocked me is it's pretty much centre frame, not in direct daylight, and I had no need to zoom in to see it, it's visible even on screen/viewfinder.

 

[willie_901]

I have not seen this sort of fringing with my 35/1.4.

I'm tempted to speculate this is due to a combination of slight over exposure, reflections and longitudinal CA. Lateral CA typically has different colors on different edges. Some of the white object is out of focus due to the extremely shallow DOF. And white can reflect the colors of nearby objects. While my guess requires the smaller aperture examples to not be over exposed, they have would different out of focus rendering.

Anyway, I don't think you should see this... especially on with an in-camera JPEG.

The longitudinal CA (upper right hand corner) looks very low and typical for this lens.


I would take some more shots with bright subjects that are further from the camera. I would place the objects in the edges and center of the frames.

The LR Defringing/CA Development tools also work on JPEGS. They just don't work as well as they do on raw.

I am using the free Adobe DNG converter (release candidate 8.4) to transform the XT-1 .RAF to DNG. Then I import the DNGs into LR 5.3. I save the original .RAFs to a back up drive.

 

[3dit0r]

Thanks. Yeah I have only had the camera a couple of days and not had a chance to do many 'real' shots with it (I came across this phenomena on a wet evening testing AF), so I'm guessing this is an unusual useage situation - one I'm hopefully not likely to encounter in my actual photography. The photos I took yesterday at sunset on the downs are gorgeous.

Not sure I follow what you suggest about over exposure? Even if it were, why would it cause purple fringing? When I stopped down, the camera was still setting shutter speed, so the overall exposure was the same in the highlights, I double checked this in camera raw.

I received my 23mm and it does exactly the same in that example, so I think it's just the lenses, unless you mean there's some weird sensor 'bloom' which is causing it? TBH I'm not that concerned now I know it's not a fault with that particular lens, but it's odd the in camera processing doesn't take care of it...

Once I get my adapter, I'll try with my Zeiss 50 1.4, which I know is relatively immune to CA.

 

[willie_901]

Over exposure could cause fringing. However if the exposure was essentially identical, then the artifacts are likely to be from over exposure. And, with the six Fujifilm primes I use it is rare to see fringing due to slight overexposure.

The fringing around the thin, white objects white look red on my screen. That's why I thought they might be a combination of reflections from the red objects in the frame and out of focus rendering. The DOF is quite thin at this distance. The in-focus (or less out of focus) white regions have no (or less fringing).

I don't think it's CA because the in-camera corrections have a good reputation.

Comparisons with the Zeiss will be interesting.

 

[jsrockit]

This is normal in my experience (when things are severely backlit or wide open with thin, brighter objects like metal). I just remove it in lightroom.