rvh23 wrote:
Received my replacement GM today, and this second one is much better centered (one somewhat weaker corner at the wide end but essentially perfect at the long end).
As Fred has demonstrated flare control is noticeably better than the Sigma, and as much as I love the Sigma, that will be the main reason for switching to the GM for me because it means even less lens changes in the field. Sharpness wise I doubt I will see any difference in my landscapes.
One thing I did notice in my brief test of the lens so far was some focus shift in the corners when I compared infinity focus at F2.8 and F5.6. It doens't affect me personally because I always focus at "taking aperture", but if you prefer to focus wide open and then stop down it might....Show more →
I'm glad you came across a good copy Richard! What are you doing about filters for it?
Good to hear more are getting good copies. I am very happy with mine and keeping it. It has made shooting sunrises an awesome experience. Let's see what filter solutions we get soon. Hope to see lee filters make an adapter for the sw150 mark ii system I have but I doubt we'll see that for another year. Besides I'm used to not shooting with filters anyway. A GND 0.9 and polarizer (which I both have in 150mm) is all I need if they release the adapter.
Fred Miranda wrote:
I'm glad you came across a good copy Richard! What are you doing about filters for it?
Thanks Fred, it's not a great copy, but maybe good enough. Despite having one weaker corner wide open when I do a terrestial "infinity test" at the wide end of its zoom range, my astro test shots last night were fine and that's the only scenario where I need all four corners to be sharp wide open. I've seen this before with other lenses and don't really understand it.
For filters I'm waiting for Nisi to start selling the S6 adapter on its own rather than only in full kits. I still have my round S5 CPL and CPL+ND64 filters which apparently will fit the S6 adapter.
Ah, who am I kidding. I'll more likely than not try another copy
This one is spectacular at 20-24mm, but unfortunately not as good as my Sigma at the wide end.
rvh23 wrote:
Ah, who am I kidding. I'll more likely than not try another copy
This one is spectacular at 20-24mm, but unfortunately not as good as my Sigma at the wide end.
Even if you remove FC from the equation?
If you focus at center, the Sigma 14-24/2.8 does have slight better corners at 14mm due to lower field curvature.
Fred Miranda wrote:
Even if you remove FC from the equation?
If you focus at center, the Sigma 14-24/2.8 does have slight better corners at 14mm due to lower field curvature.
Yes FC is not the problem with this copy. I tested it some more this morning in very still conditions, and unfortunately even stopped down to F6.3 the bottom right corner remains clearly softer than the others, and even when focus is on that corner. Here is a comparison of that corner with the next poorest corner (top R) at 14mm. Crops are from two "diagonal horizon" shots at 100% on 61MP.
So that's 2 out of 2 no good...
But certainly when FC is allowed for, the other three corners are at least as good as the Sigma, and at the long end between 20 and 24mm all four of its corners are better than what I saw on any of the Sigma samples I've tried.
Yes FC is not the problem with this copy. I tested it some more this morning in very still conditions, and unfortunately even stopped down to F6.3 the bottom right corner remains clearly softer than the others, and even when focus is on that corner. Here is a comparison of that corner with the next poorest corner (top R) at 14mm. Crops are from two "diagonal horizon" shots at 100% on 61MP.
But certainly when FC is allowed for, the other three corners are at least as good as the Sigma, and at the long end between 20 and 24mm all four of its corners are better than what I saw on any of the Sigma samples I've tried....Show more →
Do you see any asymmetry at other focal lengths? If it happens consistently throughout the range (only changing in severity), you could try this: https://www.fredmiranda.com/forum/topic/1662397
Basically it's a method to correct focus plane tilt. It should work well with primes but it's always worth investigating.
Fred Miranda wrote:
Do you see any asymmetry at other focal lengths? If it happens consistently throughout the range (only changing in severity), you could try this: https://www.fredmiranda.com/forum/topic/1662397
Basically it's a method to correct focus plane tilt. It should work well with primes but it's always worth investigating.
Thanks Fred. Unfortunately it's not consistent over the whole range. It's worst at 12-14 mm where it manifests even well stopped down, is moderate at 18mm where it disappears by 5.6, and by the time you get to 24mm it's incredibly sharp across the whole frame even wide open.
Also, I can't get the weaker corner to sharpen to the same extent as the others no matter where I focus, so tilt may not be the problem.
My 12-24 GM arrived yesterday and today I did a quick test. Sadly the left side at 12mm and especially the lower-left corner is really soft, even stopped down to f/5.6.
What's really impressive is the sharpness at 18mm wide open (besides a very slight softness in the lower-left corner again). I've never experienced any 18mm lens that sharp at f/2.8 (even compared to very good lenses like the Batis 18mm and Sigma 14-24 DG DN).
At 24mm the sharpness is comparable to the Sigma, very good but not as great as at 18mm.
Since I've bought this lens mainly because of the additional 12-14mm range compared to the Sigma zoom, I'm not really happy with the performance, especially for 3300€. And I have currently absolutely no motivation to try now many different samples until I find a great one. I will therefore just return the lens and continue to use my Sigma, which has great IQ at all focal lengths and apertures and do without the 12mm.
I can understand your frustration. It took me four attempts to find a good copy. The third and final attempts I had no motivation to keep going and I was prepared to simply give up trying.
I now have a decent copy, but the hassle has taken the edge off the excitement of getting a new lens.
At least now I can simply concentrate on my photography.
The concern I have is the extent to which the two GM 12-24 samples I've tried so far have been decentered. Both of them showed corner asymmetry even when stopped down to F7.1.
Although it took me 4 copies of the Sigma to find one that was good wide open across the whole range, all four of them were great by about 6.3.
But because both these zooms CAN be spectacularly good over the entire zoom range (better than any prime), I will keep trying to find a decent GM. I just wish there were an easier way. I would happily pay a premium for that option. But at this price, you'd be forgiven for thinking you were paying that premium.
This is indeed scary, I still have nightmares after the ordeal with Sigma and that was more manageable due to the price. Not thinking about the GM anywhere soon, but once I do I'll try to find a shop that allows me to go through several copies to find the best one. Especially for a premium priced product such as this, I think the shops should show some understanding...
Anybody know first hand what happened to a de-centered lens after they returned it?
Would be interesting to know the percentage that go back to Sony for fixing compared to those
that just go back on the shelf to be sold to the next customer with perhaps lower standards or less willingness to complain?
I would definitely recommend to get it from a local store that has a more generous return/exchange policy. My store I go to has 15 day return and 30 day exchange if it the lens has issues which made getting a new copy real easily aside from having to wait a day or two for the lens to arrive since they don't really carry many in the stores yet. It seems one has to go through at least 2 copies to get a good one but aside from that this lens is just simply amazing. B&H/adorama are pretty good at this too but I hate shipping and having to wait a long time to get a copy when I can simply just get it the same day from the local store.
My guess is that those returned lenses are sent to sony for testing to see if it's within standards and then are sold to the next customer who doesn't bother testing really, just takes a picture and if it looks good they go home with it. When I got my 16-35 GM I did quick tests in the store and was happy with it testing it at home as well on my first copy. We are definitely a picky group here but given the price I can understand
i'm waiting for one to arrive i asked my dealer to try it on before sending it to me ... however it is not normal that a lens with these costs has problems gm lenses should have rigorous tests before being placed on the market
and 
