Sony FE 12-24mm f/2.8 GM Review
p.15 #1Sony FE 12-24mm f/2.8 GM Review
Today I did a test on the brick front of my house. I used the Sony F4 and compared it to the Sony F8. I compared them at 2.8 vs 4, 5.6 vs 5.6, and f8 vs f8. Would anyone have an interest in me posting them?
Sep 15, 2020 at 12:01 PM
p.15 #2Sony FE 12-24mm f/2.8 GM Review
InFocus2014 wrote:
I’m perplexed as to how anyone could efficiently utilize these rear-mount filters.
First, I find that removing lenses outdoors is a sure-fire recipe for sensor dust - a real problem when shooting stopped-down.
If I am shooting ND filters, I always take shots of the scene without the filter, in case vegetation moved, skies are blown out (no variable filter), portions of the water too softened, etc. I can then selectively paint layers in PS for correction.
I realize that some static scenes, would work, but it sure seems like a ton of flexibility is lost, compared with front filters.
I bit the bullet...Show more →
I agree Jeff. It has limitations in usability and IQ (induced field curvature) but the advantage is carrying way smaller/lighter ND filters.
abase21 wrote
filter option from HAIDA:First, I find that removing lenses outdoors is a sure-fire recipe for sensor dust - a real problem when shooting stopped-down.
If I am shooting ND filters, I always take shots of the scene without the filter, in case vegetation moved, skies are blown out (no variable filter), portions of the water too softened, etc. I can then selectively paint layers in PS for correction.
I realize that some static scenes, would work, but it sure seems like a ton of flexibility is lost, compared with front filters.
I bit the bullet...Show more →
I agree Jeff. It has limitations in usability and IQ (induced field curvature) but the advantage is carrying way smaller/lighter ND filters.
Sep 15, 2020 at 12:05 PM
p.15 #3Sony FE 12-24mm f/2.8 GM Review
..my Nisi filter holder will arrive tomorrow, but I will buy the Haidy filter also, especially for video work. The lens is fantastic for my videos and the front filter are to big (mostly gimbal work)
Sep 15, 2020 at 12:14 PM
p.15 #4Sony FE 12-24mm f/2.8 GM Review
abase21 wrote:
..my Nisi filter holder will arrive tomorrow, but I will buy the Haidy filter also, especially for video work. The lens is fantastic for my videos and the front filter are to big (mostly gimbal work)
I've used them also mainly for video and timelapse.
What Gimbal do you have? My Ronin SC would take the 12-24GM (and also the Sigma 14-24) only with lots of counterweights.
..my Nisi filter holder will arrive tomorrow, but I will buy the Haidy filter also, especially for video work. The lens is fantastic for my videos and the front filter are to big (mostly gimbal work)
I've used them also mainly for video and timelapse.
What Gimbal do you have? My Ronin SC would take the 12-24GM (and also the Sigma 14-24) only with lots of counterweights.
Sep 15, 2020 at 12:45 PM
p.15 #5Sony FE 12-24mm f/2.8 GM Review
Fred Miranda wrote:
Is the lens decentered or focal plane tilted? The best way to find out is to focus at the very corners individually and compare them. If they corners look equal, the lens is not decentered and there is hope of fixing the asymmetry. The trick with zooms is that as we change focal length, the focal plane usually gets swung or tilted and therefore shims may not work for all FLs.There is definately a consistent tilt/swing that has improved across the whole range with the shim I installed. But in addition to that, the lower left corner does seem slightly weaker (perhaps a little more astigmatism) even when each corner is focused on in turn. I'm really on the fence with this copy. I know it could be better but it could be a whole lot worse too, and stopped down a bit it's fine.Does that softer corner improve when focusing on it? If not, the lens could have a decentered element as well.
Shimming can fix with focal plane tilt/swing but it won't be useful if the lens is decentered.
A fellow FM member just emailed me his centering test and his lens looked excellent at 12mm and 24mm.
I received mine this AM and thoroughly tested it. The lower-left corner is ever so slightly out (almost imperceptible), but not enough to ever worry about. Overall, this is an outstanding lens! Whew!! Well done, Sony.
I can see where this will likely become on of my favorite lenses and it (along with the GM135 and a few ART lenses) might even keep me from ordering an R5.
Edited on Sep 15, 2020 at 02:55 PM · View previous versions
rvh23 wrote
Fred Miranda wrote
rvh23 wrote
I realized tonight I've been doing this the hard way. Putting the adhesive shims temporarily on the outside of the lens' mount plate (or on the camera's mount) should work just as well for exploratory purposes, and avoids removing the plate on each iteration. I will try some more variations tomorrow, and post if I get any further imrovements.Shimming can fix with focal plane tilt/swing but it won't be useful if the lens is decentered.
A fellow FM member just emailed me his centering test and his lens looked excellent at 12mm and 24mm.
I received mine this AM and thoroughly tested it. The lower-left corner is ever so slightly out (almost imperceptible), but not enough to ever worry about. Overall, this is an outstanding lens! Whew!! Well done, Sony.
I can see where this will likely become on of my favorite lenses and it (along with the GM135 and a few ART lenses) might even keep me from ordering an R5.
Edited on Sep 15, 2020 at 02:55 PM · View previous versions
Sep 15, 2020 at 02:39 PM
p.15 #6Sony FE 12-24mm f/2.8 GM Review
Bobu wrote:
I've used them also mainly for video and timelapse.
What Gimbal do you have? My Ronin SC would take the 12-24GM (and also the Sigma 14-24) only with lots of counterweights.
I have also the Ronin SC but it works without counterweights. The eyecup hits the motor, but for my moves it doesn’t matter. The Ronin S would surely be the better choice for the lens, but I like the lightweight of the SC
abase21 wrote
..my Nisi filter holder will arrive tomorrow, but I will buy the Haidy filter also, especially for video work. The lens is fantastic for my videos and the front filter are to big (mostly gimbal work)What Gimbal do you have? My Ronin SC would take the 12-24GM (and also the Sigma 14-24) only with lots of counterweights.
I have also the Ronin SC but it works without counterweights. The eyecup hits the motor, but for my moves it doesn’t matter. The Ronin S would surely be the better choice for the lens, but I like the lightweight of the SC
Sep 15, 2020 at 02:53 PM
p.15 #7Sony FE 12-24mm f/2.8 GM Review
Fred Miranda wrote:
Does that softer corner improve when focusing on it? If not, the lens could have a decentered element as well.
Shimming can fix focal plane tilt/swing but it won't be useful if the lens is decentered.
A fellow FM member just emailed me his centering test and his lens looked excellent at 12mm and 24mm.
With the shim in place, the lens is about as symmetric (on average across the zoom range) as I can get it. When focusing on each corner in turn, the lower left remains not quite as sharp as the others at f2.8 - f5.6, but by 6.3 it's hard to tell any differences. I have lens #4 on it's way to me
but will hang on to #3 until I know I can get a better one.
I suspect that if I was still shooting with 42mp or less this one would have sufficed, but these lenses are meant to be made for 61mp+.
Does that softer corner improve when focusing on it? If not, the lens could have a decentered element as well.
Shimming can fix focal plane tilt/swing but it won't be useful if the lens is decentered.
A fellow FM member just emailed me his centering test and his lens looked excellent at 12mm and 24mm.
With the shim in place, the lens is about as symmetric (on average across the zoom range) as I can get it. When focusing on each corner in turn, the lower left remains not quite as sharp as the others at f2.8 - f5.6, but by 6.3 it's hard to tell any differences. I have lens #4 on it's way to me
but will hang on to #3 until I know I can get a better one. I suspect that if I was still shooting with 42mp or less this one would have sufficed, but these lenses are meant to be made for 61mp+.
Sep 15, 2020 at 04:26 PM
p.15 #8Sony FE 12-24mm f/2.8 GM Review
InFocus2014 wrote:
Is the lens decentered or focal plane tilted? The best way to find out is to focus at the very corners individually and compare them. If they corners look equal, the lens is not decentered and there is hope of fixing the asymmetry. The trick with zooms is that as we change focal length, the focal plane usually gets swung or tilted and therefore shims may not work for all FLs.There is definately a consistent tilt/swing that has improved across the whole range with the shim I installed. But in addition to that, the lower left corner does seem slightly weaker (perhaps a little more astigmatism) even when each corner is focused on in turn. I'm really on the fence with this copy. I know it could be better but it could be a whole lot worse too, and stopped down a bit it's fine.Does that softer corner improve when focusing on it? If not, the lens could have a decentered element as well.
Shimming can fix with focal plane tilt/swing but it won't be useful if the lens is decentered.
A fellow FM member just emailed me his centering test and his lens looked excellent at 12mm and 24mm.I received mine this AM and thoroughly tested it. The lower-left corner is ever so slightly out (almost imperceptible), but not enough to ever worry about. Overall, this is an outstanding lens! Whew!! Well done, Sony.
I can see where this will likely become on of my favorite lenses and it (along with the GM135 and a few ART lenses) might even keep me from ordering an R5.
Congratulations on the lens. I agree this lens pretty much eliminates the need to carry anything else in its range (if you get a good one). I am really impressed by its ability to shoot against the sun, and have no problems with its color palette unlike the F4.
Fred Miranda wrote
rvh23 wrote
Fred Miranda wrote
rvh23 wrote
I realized tonight I've been doing this the hard way. Putting the adhesive shims temporarily on the outside of the lens' mount plate (or on the camera's mount) should work just as well for exploratory purposes, and avoids removing the plate on each iteration. I will try some more variations tomorrow, and post if I get any further imrovements.Shimming can fix with focal plane tilt/swing but it won't be useful if the lens is decentered.
A fellow FM member just emailed me his centering test and his lens looked excellent at 12mm and 24mm.
I can see where this will likely become on of my favorite lenses and it (along with the GM135 and a few ART lenses) might even keep me from ordering an R5.
Congratulations on the lens. I agree this lens pretty much eliminates the need to carry anything else in its range (if you get a good one). I am really impressed by its ability to shoot against the sun, and have no problems with its color palette unlike the F4.
Sep 15, 2020 at 04:32 PM
p.15 #9Sony FE 12-24mm f/2.8 GM Review
rvh23 wrote:
Is the lens decentered or focal plane tilted? The best way to find out is to focus at the very corners individually and compare them. If they corners look equal, the lens is not decentered and there is hope of fixing the asymmetry. The trick with zooms is that as we change focal length, the focal plane usually gets swung or tilted and therefore shims may not work for all FLs.There is definately a consistent tilt/swing that has improved across the whole range with the shim I installed. But in addition to that, the lower left corner does seem slightly weaker (perhaps a little more astigmatism) even when each corner is focused on in turn. I'm really on the fence with this copy. I know it could be better but it could be a whole lot worse too, and stopped down a bit it's fine.Does that softer corner improve when focusing on it? If not, the lens could have a decentered element as well.
Shimming can fix with focal plane tilt/swing but it won't be useful if the lens is decentered.
A fellow FM member just emailed me his centering test and his lens looked excellent at 12mm and 24mm.I received mine this AM and thoroughly tested it. The lower-left corner is ever so slightly out (almost imperceptible), but not enough to ever worry about. Overall, this is an outstanding lens! Whew!! Well done, Sony.
I can see where this will likely become on of my favorite lenses and it (along with the GM135 and a few ART lenses) might even keep me from ordering an R5.Congratulations on the lens. I agree this lens pretty much eliminates the need to carry anything else in its range (if you get a good one). I am really impressed by its ability to shoot against the sun, and have no problems with its color palette unlike the F4.
Some of the criticism I received from my review was that I stated (and showed in the crops) that the Sony 12-24/2.8 GM outperformed the Sigma 14-24/2.8 at wide apertures in terms of resolution on the A7R IV. I also wrote that flare resistance was better compared to the Sigma or even the Voigtlander 12/5.6 III prime.
I was surprised by this performance level because other G and GM wide angle and normal zooms were not quite there.
I'm glad you are enjoying the lens and confirmed these findings.
You wrote that you used "self-adhesive copper foil" for the shimming. How thick is that and where did you apply it?
InFocus2014 wrote
Fred Miranda wrote
rvh23 wrote
Fred Miranda wrote
rvh23 wrote
I realized tonight I've been doing this the hard way. Putting the adhesive shims temporarily on the outside of the lens' mount plate (or on the camera's mount) should work just as well for exploratory purposes, and avoids removing the plate on each iteration. I will try some more variations tomorrow, and post if I get any further imrovements.Shimming can fix with focal plane tilt/swing but it won't be useful if the lens is decentered.
A fellow FM member just emailed me his centering test and his lens looked excellent at 12mm and 24mm.
I can see where this will likely become on of my favorite lenses and it (along with the GM135 and a few ART lenses) might even keep me from ordering an R5.
Some of the criticism I received from my review was that I stated (and showed in the crops) that the Sony 12-24/2.8 GM outperformed the Sigma 14-24/2.8 at wide apertures in terms of resolution on the A7R IV. I also wrote that flare resistance was better compared to the Sigma or even the Voigtlander 12/5.6 III prime.
I was surprised by this performance level because other G and GM wide angle and normal zooms were not quite there.
I'm glad you are enjoying the lens and confirmed these findings.
You wrote that you used "self-adhesive copper foil" for the shimming. How thick is that and where did you apply it?
Sep 15, 2020 at 04:46 PM
p.15 #10Sony FE 12-24mm f/2.8 GM Review
Fred Miranda wrote:
There is definately a consistent tilt/swing that has improved across the whole range with the shim I installed. But in addition to that, the lower left corner does seem slightly weaker (perhaps a little more astigmatism) even when each corner is focused on in turn. I'm really on the fence with this copy. I know it could be better but it could be a whole lot worse too, and stopped down a bit it's fine.Does that softer corner improve when focusing on it? If not, the lens could have a decentered element as well.
Shimming can fix with focal plane tilt/swing but it won't be useful if the lens is decentered.
A fellow FM member just emailed me his centering test and his lens looked excellent at 12mm and 24mm.I received mine this AM and thoroughly tested it. The lower-left corner is ever so slightly out (almost imperceptible), but not enough to ever worry about. Overall, this is an outstanding lens! Whew!! Well done, Sony.
I can see where this will likely become on of my favorite lenses and it (along with the GM135 and a few ART lenses) might even keep me from ordering an R5.Congratulations on the lens. I agree this lens pretty much eliminates the need to carry anything else in its range (if you get a good one). I am really impressed by its ability to shoot against the sun, and have no problems with its color palette unlike the F4.Some of the criticism I received from my review was that I stated (and showed in the crops) that the Sony 12-24/2.8 GM outperformed the Sigma 14-24/2.8 at wide apertures in terms of resolution on the A7R IV. I also wrote that flare resistance was better compared to the Sigma or even the Voigtlander 12/5.6 III prime.
I was surprised by this performance level because other G and GM wide angle and normal zooms were not quite there.
I'm glad you are enjoying the lens and confirmed these findings.
Yes it's flare performance is amazing. So good in fact, I sold my Loxia 21 despite my preference for its sunstar shape. Once I have a good copy, I expect this lens to be prettty much be glued to my camera.
rvh23 wrote
InFocus2014 wrote
Fred Miranda wrote
rvh23 wrote
Fred Miranda wrote
Is the lens decentered or focal plane tilted? The best way to find out is to focus at the very corners individually and compare them. If they corners look equal, the lens is not decentered and there is hope of fixing the asymmetry. The trick with zooms is that as we change focal length, the focal plane usually gets swung or tilted and therefore shims may not work for all FLs.Shimming can fix with focal plane tilt/swing but it won't be useful if the lens is decentered.
A fellow FM member just emailed me his centering test and his lens looked excellent at 12mm and 24mm.
I can see where this will likely become on of my favorite lenses and it (along with the GM135 and a few ART lenses) might even keep me from ordering an R5.
I was surprised by this performance level because other G and GM wide angle and normal zooms were not quite there.
I'm glad you are enjoying the lens and confirmed these findings.
Yes it's flare performance is amazing. So good in fact, I sold my Loxia 21 despite my preference for its sunstar shape. Once I have a good copy, I expect this lens to be prettty much be glued to my camera.
Sep 15, 2020 at 05:01 PM
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p.15 #11Sony FE 12-24mm f/2.8 GM Review
The flare performance really blew me away. That coating is just magic. Glad to hear more are getting better copies. This lens is an absolute dream to shoot sunrise/sunsets with. The fact that it holds on to the contrast over the bright sun makes the images look better. Once this insane fire cloud has gone I wanna get out to the beach to shoot some images! Curious to see if i can make my 150mm heida glass work with the nisi s6. Don't see a reason why not. Should fit fine.
Sep 15, 2020 at 05:09 PM
p.15 #12Sony FE 12-24mm f/2.8 GM Review
Fred Miranda wrote:
You wrote that you used "self-adhesive copper foil" for the shimming. How thick is that and where did you apply it?
My best guess is that it's about 10um thick. I put a small square of it under the lens' mount plate a the position of one of the four mounting screws. Becuase it's so thin, it's easy to punch a hole in it to allow the screw to go through.
It's not hard to get access (just four screws holding the plate), but it's a little fiddly because there are infinity-adjust shims already in place that are dislodged easily. Also, you need to be gentle moving the plate once the screws are undone because it's connected to a flat flex cable to provide signals to the electronic contacts. I don't plan on doing this to any further copies...
You wrote that you used "self-adhesive copper foil" for the shimming. How thick is that and where did you apply it?
My best guess is that it's about 10um thick. I put a small square of it under the lens' mount plate a the position of one of the four mounting screws. Becuase it's so thin, it's easy to punch a hole in it to allow the screw to go through.
It's not hard to get access (just four screws holding the plate), but it's a little fiddly because there are infinity-adjust shims already in place that are dislodged easily. Also, you need to be gentle moving the plate once the screws are undone because it's connected to a flat flex cable to provide signals to the electronic contacts. I don't plan on doing this to any further copies...
Sep 15, 2020 at 05:26 PM
p.15 #13Sony FE 12-24mm f/2.8 GM Review
rvh23 wrote:
My best guess is that it's about 10um thick. I put a small square of it under the lens' mount plate a the position of one of the four mounting screws. Becuase it's so thin, it's easy to punch a hole in it to allow the screw to go through.
It's not hard to get access (just four screws holding the plate), but it's a little fiddly because there are infinity-adjust shims already in place that are dislodged easily. Also, you need to be gentle moving the plate once the screws are undone because it's connected to a flat flex...Show more →
I would caution about galvanic corrosion between copper and the stainless steel camera bayonet if anyone intends to use it for their camera adjustment, much less so the nickel/chrome plated brass bayonets on the lens side. Lens infinity adjustment shims I've seen have all been brass.
Another concern is how spongy the adhesive layer is. Perhaps the compression of the mount screws crushes the adhesive layer sufficiently...
Good job @rvh23 on adjusting your GM lens! There was a substantial improvement to the radial symmetry in your corner crops.
Fred Miranda wrote
You wrote that you used "self-adhesive copper foil" for the shimming. How thick is that and where did you apply it?It's not hard to get access (just four screws holding the plate), but it's a little fiddly because there are infinity-adjust shims already in place that are dislodged easily. Also, you need to be gentle moving the plate once the screws are undone because it's connected to a flat flex...Show more →
I would caution about galvanic corrosion between copper and the stainless steel camera bayonet if anyone intends to use it for their camera adjustment, much less so the nickel/chrome plated brass bayonets on the lens side. Lens infinity adjustment shims I've seen have all been brass.
Another concern is how spongy the adhesive layer is. Perhaps the compression of the mount screws crushes the adhesive layer sufficiently...
Good job @rvh23 on adjusting your GM lens! There was a substantial improvement to the radial symmetry in your corner crops.
Sep 15, 2020 at 05:35 PM
p.15 #14Sony FE 12-24mm f/2.8 GM Review
inksandpaper wrote:
My best guess is that it's about 10um thick. I put a small square of it under the lens' mount plate a the position of one of the four mounting screws. Becuase it's so thin, it's easy to punch a hole in it to allow the screw to go through.
It's not hard to get access (just four screws holding the plate), but it's a little fiddly because there are infinity-adjust shims already in place that are dislodged easily. Also, you need to be gentle moving the plate once the screws are undone because it's connected to a flat flex cable to provide signals to the electronic contacts. I don't plan on doing this to any further copies...I would caution about galvanic corrosion between copper and the stainless steel camera bayonet if anyone intends to use it for their camera adjustment, much less so the nickel/chrome plated brass bayonets on the lens side. Lens infinity adjustment shims I've seen have all been brass.
Another concern is how spongy the adhesive layer is. Perhaps the compression of the mount screws crushes the adhesive layer sufficiently...
Good job @rvh23@ on adjusting your GM lens! There was a substantial improvement to the radial symmetry in your corner crops.
Thanks for your comment, it was Fred's pointer to your recent thread about shimming lenses that reminded me this might be an option.
The placement of the shim as I described it above was where I initially placed it. Note that I am talking about the mounting plate on the lens, not the camera. When I went back to see if I could further improve it yesterday, I actually ended up putting it between two infinity shims rather than on the back of the lens plate. So if the shims are chrome plated brass, rather than stainless, would that addres the galvanic corrosion concern? (the shims are not brass colored in appearance)
I had wondered about the sponginess of the adhesive, but more in relation to trying to measure the thickness of the shim. Hopefully the mount screw pressure is indeed enough to ensure long term stability.
rvh23 wrote
Fred Miranda wrote
You wrote that you used "self-adhesive copper foil" for the shimming. How thick is that and where did you apply it?It's not hard to get access (just four screws holding the plate), but it's a little fiddly because there are infinity-adjust shims already in place that are dislodged easily. Also, you need to be gentle moving the plate once the screws are undone because it's connected to a flat flex cable to provide signals to the electronic contacts. I don't plan on doing this to any further copies...
Another concern is how spongy the adhesive layer is. Perhaps the compression of the mount screws crushes the adhesive layer sufficiently...
Good job @rvh23@ on adjusting your GM lens! There was a substantial improvement to the radial symmetry in your corner crops.
Thanks for your comment, it was Fred's pointer to your recent thread about shimming lenses that reminded me this might be an option.
The placement of the shim as I described it above was where I initially placed it. Note that I am talking about the mounting plate on the lens, not the camera. When I went back to see if I could further improve it yesterday, I actually ended up putting it between two infinity shims rather than on the back of the lens plate. So if the shims are chrome plated brass, rather than stainless, would that addres the galvanic corrosion concern? (the shims are not brass colored in appearance)
I had wondered about the sponginess of the adhesive, but more in relation to trying to measure the thickness of the shim. Hopefully the mount screw pressure is indeed enough to ensure long term stability.
Sep 15, 2020 at 06:59 PM
p.15 #15Sony FE 12-24mm f/2.8 GM Review
I did some more testing this morning with my shimmed GM and found that although corner symmetry was improved by the shim, focus distance reported in the camera was less accurate especially at distances beyond about 1m, and probably more importantly field curvature was significantly increased. Whereas previously FC was negligible except at the very wide end, after shimming it was clearly visible even at the long end. So I've removed the shim and restored the lens to its original condition
Sep 15, 2020 at 08:17 PM
p.15 #16Sony FE 12-24mm f/2.8 GM Review
rvh23 wrote:
I did some more testing this morning with my shimmed GM and found that although corner symmetry was improved by the shim, focus distance reported in the camera was less accurate especially at distances beyond about 1m, and probably more importantly field curvature was significantly increased. Whereas previously FC was negligible except at the very wide end, after shimming it was clearly visible even at the long end. So I've removed the shim and restored the lens to its original condition
I've learned (from @inksandpaper) that shimming needs to be done in pairs (on two screws instead of one). If you only add shim to one of the 4 screws, the bayonet will bend and this could affect mounting-unmounting of the lens (and perhaps cause damage overtime). Keep in mind that you may have to adjust tilt and swing which means adding shims to 3 screws. For example top left, bottom left and top right. (The top left screw would get the sum of the shim adjustment for swing and tilt)
I did some more testing this morning with my shimmed GM and found that although corner symmetry was improved by the shim, focus distance reported in the camera was less accurate especially at distances beyond about 1m, and probably more importantly field curvature was significantly increased. Whereas previously FC was negligible except at the very wide end, after shimming it was clearly visible even at the long end. So I've removed the shim and restored the lens to its original condition
I've learned (from @inksandpaper) that shimming needs to be done in pairs (on two screws instead of one). If you only add shim to one of the 4 screws, the bayonet will bend and this could affect mounting-unmounting of the lens (and perhaps cause damage overtime). Keep in mind that you may have to adjust tilt and swing which means adding shims to 3 screws. For example top left, bottom left and top right. (The top left screw would get the sum of the shim adjustment for swing and tilt)
Sep 15, 2020 at 09:06 PM
p.15 #17Sony FE 12-24mm f/2.8 GM Review
Fred Miranda wrote:
I've learned (from @inksandpaper@) that shimming needs to be done in pairs (on two screws instead of one). If you only add shim to one of the 4 screws, the bayonet will bend and this could affect mounting-unmounting of the lens (and perhaps cause damage overtime). Keep in mind that you may have to adjust tilt and swing which means adding shims to 3 screws. For example top left, bottom left and top right. (The top left screw would get the sum of the shim adjustment for swing and tilt)
Agreed, and for long term use I would be inclined to place about 1/2 the thickness shim at each of the two neighboring screws in additionto the shim I placed in one corner. Although it might not be necessary for such a thin shim.
But as proof of concept the single shim was fine. Unfortunately it showed shimming couldn't solve the asymmetry issue of this particular lens without introducing other problems like increasd FC, which would defeat the point of the exercise. My only option for better performance appears to be to try more copies.
rvh23 wrote
I did some more testing this morning with my shimmed GM and found that although corner symmetry was improved by the shim, focus distance reported in the camera was less accurate especially at distances beyond about 1m, and probably more importantly field curvature was significantly increased. Whereas previously FC was negligible except at the very wide end, after shimming it was clearly visible even at the long end. So I've removed the shim and restored the lens to its original conditionAgreed, and for long term use I would be inclined to place about 1/2 the thickness shim at each of the two neighboring screws in additionto the shim I placed in one corner. Although it might not be necessary for such a thin shim.
But as proof of concept the single shim was fine. Unfortunately it showed shimming couldn't solve the asymmetry issue of this particular lens without introducing other problems like increasd FC, which would defeat the point of the exercise. My only option for better performance appears to be to try more copies.
Sep 15, 2020 at 09:50 PM
p.15 #18Sony FE 12-24mm f/2.8 GM Review
rvh23 wrote:
I've learned (from @inksandpaper@@) that shimming needs to be done in pairs (on two screws instead of one). If you only add shim to one of the 4 screws, the bayonet will bend and this could affect mounting-unmounting of the lens (and perhaps cause damage overtime). Keep in mind that you may have to adjust tilt and swing which means adding shims to 3 screws. For example top left, bottom left and top right. (The top left screw would get the sum of the shim adjustment for swing and tilt)Agreed, and for long term use I would be inclined to place about 1/2 the thickness shim at each of the two neighboring screws in additionto the shim I placed in one corner. Although it might not be necessary for such a thin shim.
But as proof of concept the single shim was fine. Unfortunately it showed shimming couldn't solve the asymmetry issue of this particular lens without introducing other problems like increasd FC, which would defeat the point of the exercise. My only option for better performance appears to be to try more copies.
It's the main reason I shy away from zoom lenses, especially complex designs with multiple asphericals and so many elements like the 12-24GM. This lens is worth the trouble though.
Fred Miranda wrote
rvh23 wrote
I did some more testing this morning with my shimmed GM and found that although corner symmetry was improved by the shim, focus distance reported in the camera was less accurate especially at distances beyond about 1m, and probably more importantly field curvature was significantly increased. Whereas previously FC was negligible except at the very wide end, after shimming it was clearly visible even at the long end. So I've removed the shim and restored the lens to its original conditionBut as proof of concept the single shim was fine. Unfortunately it showed shimming couldn't solve the asymmetry issue of this particular lens without introducing other problems like increasd FC, which would defeat the point of the exercise. My only option for better performance appears to be to try more copies.
It's the main reason I shy away from zoom lenses, especially complex designs with multiple asphericals and so many elements like the 12-24GM. This lens is worth the trouble though.
Sep 15, 2020 at 09:58 PM
p.15 #19Sony FE 12-24mm f/2.8 GM Review
rvh23 wrote:
I actually ended up putting it between two infinity shims rather than on the back of the lens plate. So if the shims are chrome plated brass, rather than stainless, would that addres the galvanic corrosion concern? (the shims are not brass colored in appearance)
I think it should be fine.
I did some more testing this morning with my shimmed GM and found that although corner symmetry was improved by the shim, focus distance reported in the camera was less accurate especially at distances beyond about 1m, and probably more importantly field curvature was significantly increased. Whereas previously FC was negligible except at the very wide end, after shimming it was clearly visible even at the long end. So I've removed the shim and restored the lens to its original condition
That's strange. Shimming tilt at the mount does not cause FC to increase significantly. I wonder what's going on. What do you mean by the focus distance reported was less accurate? How much less accurate was it? Is it commensurate with the focus shift you would expect on-axis for a 10-micron correction induced at the screw, which is ~5 microns only on-axis?
I actually ended up putting it between two infinity shims rather than on the back of the lens plate. So if the shims are chrome plated brass, rather than stainless, would that addres the galvanic corrosion concern? (the shims are not brass colored in appearance)
I think it should be fine.
I did some more testing this morning with my shimmed GM and found that although corner symmetry was improved by the shim, focus distance reported in the camera was less accurate especially at distances beyond about 1m, and probably more importantly field curvature was significantly increased. Whereas previously FC was negligible except at the very wide end, after shimming it was clearly visible even at the long end. So I've removed the shim and restored the lens to its original condition
That's strange. Shimming tilt at the mount does not cause FC to increase significantly. I wonder what's going on. What do you mean by the focus distance reported was less accurate? How much less accurate was it? Is it commensurate with the focus shift you would expect on-axis for a 10-micron correction induced at the screw, which is ~5 microns only on-axis?
Sep 16, 2020 at 06:50 AM
p.15 #20Sony FE 12-24mm f/2.8 GM Review
rvh23 wrote:
Is the lens decentered or focal plane tilted? The best way to find out is to focus at the very corners individually and compare them. If they corners look equal, the lens is not decentered and there is hope of fixing the asymmetry. The trick with zooms is that as we change focal length, the focal plane usually gets swung or tilted and therefore shims may not work for all FLs.There is definately a consistent tilt/swing that has improved across the whole range with the shim I installed. But in addition to that, the lower left corner does seem slightly weaker (perhaps a little more astigmatism) even when each corner is focused on in turn. I'm really on the fence with this copy. I know it could be better but it could be a whole lot worse too, and stopped down a bit it's fine.Does that softer corner improve when focusing on it? If not, the lens could have a decentered element as well.
Shimming can fix with focal plane tilt/swing but it won't be useful if the lens is decentered.
A fellow FM member just emailed me his centering test and his lens looked excellent at 12mm and 24mm.I received mine this AM and thoroughly tested it. The lower-left corner is ever so slightly out (almost imperceptible), but not enough to ever worry about. Overall, this is an outstanding lens! Whew!! Well done, Sony.
I can see where this will likely become on of my favorite lenses and it (along with the GM135 and a few ART lenses) might even keep me from ordering an R5.Congratulations on the lens. I agree this lens pretty much eliminates the need to carry anything else in its range (if you get a good one). I am really impressed by its ability to shoot against the sun, and have no problems with its color palette unlike the F4.
Congratulations to you both for satisfified copies!
it's not easy to exchange till a well banlanced copy here. I decide to wait for 1 more year to try my luck
InFocus2014 wrote
Fred Miranda wrote
rvh23 wrote
Fred Miranda wrote
rvh23 wrote
I realized tonight I've been doing this the hard way. Putting the adhesive shims temporarily on the outside of the lens' mount plate (or on the camera's mount) should work just as well for exploratory purposes, and avoids removing the plate on each iteration. I will try some more variations tomorrow, and post if I get any further imrovements.Shimming can fix with focal plane tilt/swing but it won't be useful if the lens is decentered.
A fellow FM member just emailed me his centering test and his lens looked excellent at 12mm and 24mm.
I can see where this will likely become on of my favorite lenses and it (along with the GM135 and a few ART lenses) might even keep me from ordering an R5.
Congratulations to you both for satisfified copies!
it's not easy to exchange till a well banlanced copy here. I decide to wait for 1 more year to try my luck
Sep 16, 2020 at 09:19 AM