p.37 #1 · Pre-order: Sony FE 35mm f/1.4 GM ($1,399)
Teo Rey wrote:
I thought that lateral CA only appears on the plane of focus? The CA on the GM that people are most concerned about is on the focus plane, no?
Basically lateral CA is variation in the "magnification" of the different colors of light and axial CA is a variation of each "wavelength" of light.
The former is visible at the edges and the latter anywhere in the frame (including center). Purple fringing is longitudinal/axial CA and also deals with wavelength discrepancy. The only difference is that it is visible on the focused area.
Lateral CA does not go away when stopping the lens down but it's easy to correct without significant IQ loss.
Longitudinal/axial CA goes away when stopping the lens down. Wide open, it's not easy to correct but can be masked in post.
p.37 #2 · Pre-order: Sony FE 35mm f/1.4 GM ($1,399)
Fred Miranda wrote:
I know it's hard to resist but we should not compare color aberration correction from lenses with different focal lengths.
Instead we should compare the FE 24/1.4 GM to other 24mm f/1.4 lenses. The FE 24/1.4 GM is well regarded because it actually does better than the competition in regards to CA and resolution while being compact for what it is.
Here is a high contrast sample showing axial CA on the metal chain: (front of plane of focus)
my personal threshold is if you have to post a 100% pic to see the problem, I usually don't care. I mean if you look at pixel level, there is sooo many things to nit pick on.
It is all about alternatives. I still kept my 24mm gm for years even though the fringing is so obvious in certain conditions. 35mm, there is the sigma f1.2 which does almost everything well in terms of IQ, thus the 35mm gm has to perform better than the 24mm gm for me. My bar for the 35mm is higher because of the sigma 35mm f1.2.
p.37 #3 · Pre-order: Sony FE 35mm f/1.4 GM ($1,399)
wind30 wrote:
my personal threshold is if you have to post a 100% pic to see the problem, I usually don't care. I mean if you look at pixel level, there is sooo many things to nit pick on.
It is all about alternatives. I still kept my 24mm gm for years even though the fringing is so obvious in certain conditions. 35mm, there is the sigma f1.2 which does almost everything well in terms of IQ, thus the 35mm gm has to perform better than the 24mm gm for me. My bar for the 35mm is higher because of the sigma 35mm f1.2.
The Sigma 35/1.2 has indeed better axial CA correction if you compare it to the 24/1.4 GM but like I said, it's not really fair to compare them.
In the case of the new FE 35/1.4 GM, it's still a question mark for me, but from what I've seen so far, axial CA is visible in some images, although it seems to do better than most 35mm f/1.4 lenses available. Perhaps the Sigma 35/1.2 will still have better correction. Not sure.
p.37 #5 · Pre-order: Sony FE 35mm f/1.4 GM ($1,399)
I never loved the 35mm FE, to the point where I've used it maybe two total days and haven't touched it since. I love the CV 40 but wants something with AF between the 24GM and 55/85.
Should I order this sight unseen, or has the ship sailed in terms of pre-orders times and I should wait for reviews and folks to post their shots?
I remember the 24GM being hard to get for 6 months or more.
p.37 #6 · Pre-order: Sony FE 35mm f/1.4 GM ($1,399)
DavidBM wrote:
Longitudinal CA can appear to be on the plane of focus, even though strictly speaking it isn’t, unlike LaCA which is strictly on the focus plane.
This happens when there is an in focus subject - let’s say some trees at infinity, but some colours are out of focus (commonly violet) and so form a kind of halo around it of fringing. It’s longitudinal because the different colours are in focus at different subject distances.
This can sometime be visually hard to distinguish (or can be combined with) lateral CA where the colours are in the focus the same subject distance. But here you get fringing because the magnification is a little different between colour channels, causing fringing....Show more →
Hmm, that's very interesting. Thank you for the explanation! So then if it's hard to tell them apart, how can we know which is which?
Lateral CA happens outside the image center with high contrast structures, and doesn't go away when stopped down and can be in the focal plane. Longitudinal CA happens just before and after the focal point, being either green or purple, but is fixed by stopping down 2-3 stops on most lenses (like the GM 24 or Sigma 35/1.2). Both result from a lens' inability to focus wave lengths optimally, but look at the link to see how they differ.
Practically speaking, I recently purchased a ZF 28/2. Wide open at f2, if I focused on a nail from 2 feet away, just before and behind were purple and green around the nail. If it were an APO lens, we wouldn't see that (or much much less). By f4 on the ZF 28, the false color is gone/insignificant. However when I checked the lens at infinite, I saw lateral CA purple outlining on tree branches even at f8. It's an older lens now, but not that well corrected for either type of CA.
p.37 #8 · Pre-order: Sony FE 35mm f/1.4 GM ($1,399)
wind30 wrote:
I was beginning to think I am alone about the 24mm gm issue with color fringing. Example of the 24mm gm below. It is really a significant issue so I am not sure why 24mm is so highly rated. It is a good lens but it is in no way perfect. I am beginning to feel the same way about the 35mm f1.4gm. I don't want to sell my 35mm f1.2 which honestly I have no complains about in Image quality. Sure there is some color fringing too but it is really quite low and below my threshold.
The sort of compromises you have to take to have a sharp and compact lens... to know for sure if the GM 35/1.4 meets your expectation, best to shoot with one. But likely you will have to keep your Sigma. Fringing is annoying for me for sure, but less so to me than the weight and size one has to take to suppress them at the current tech. I’m pretty sure all of the high-end Canikon RF and Z lenses will have no problem with this. You don’t mind the weight, those might be a better system, especially Nikon Z. Ignoring the weight and size, the two Nikon S 58/0.95 and 50/1.2 are very sharp and well corrected (remarkably so), even more than the Canon RF counterpart. Either that or you need to keep buying those very fast and big Sigma, though I always prefer first party offerings.
p.37 #11 · Pre-order: Sony FE 35mm f/1.4 GM ($1,399)
Pre-ordered as well at a large photography shop that sells as well online (shops are closed, lockdown) here in Switzerland. First time I pre-ordered a lens. Lets see if I was quick enough to get the lens before my birthday in April
p.37 #12 · Pre-order: Sony FE 35mm f/1.4 GM ($1,399)
Fred Miranda wrote:
Basically lateral CA is variation in the "magnification" of the different colors of light and axial CA is a variation of each "wavelength" of light.
The former is visible at the edges and the latter anywhere in the frame (including center). Purple fringing is longitudinal/axial CA and also deals with wavelength discrepancy. The only difference is that it is visible on the focused area.
Lateral CA does not go away when stopping the lens down but it's easy to correct without significant IQ loss.
Longitudinal/axial CA goes away when stopping the lens down. Wide open, it's not easy to correct but can be masked in post....Show more →
Here's a practical advice on how to correct Longitudinal/axial CA in Lightroom:
1. Tick 'on' the corrections of chromatic aberrations and make sure you have right colors setup there - this of course does nothing to longitudinal/axial CA (but it usually corrects the lateral CA if there is any)
2. Take 'Adjustment brush' and paint with it on the areas where you have longitudinal/axial CA in the picture. Then hit hard with the 'Defringe' on the adjustment brush panel. This usually corrects some of the longitudinal fringing, sometimes almost all of it, though results vary.
I've been correcting some of the Batis 25 images when shooting wide open and Fred's example of GM fringing looks very very similar. Of course massive fringing cannot be totally corrected, but most of the time the irritating aspects (ie. bright non natural colors) can be reduced not to take attention in the image.
p.37 #13 · Pre-order: Sony FE 35mm f/1.4 GM ($1,399)
What a great discussion on the CA topic !
Can you help me and try to tell what kind of CA the fringing on the branches in the background is (f11, but focused close):
I chose this shot as it's not overexposed, which helps a bit I think.
In other shots I have from that forest, the sky is overblown, which makes the matter even worse, even though they're at f8 and the branches in the background are more or less in focus...
!
