ggx145 wrote:
Does it take filters? I have the sigma, minor problem that it does not take polarizers but has a mount for ND in the back.
It’s like the other superwide zooms with a filter slot on the rear. Hopefully Kass will make an adapter like they did for the Sony version. I suspect they will if this lens becomes as popular as I assume it will.
For thread posterity. I got my A7R6 a few hours ago, so keep in mind that I'm not at all facile with the camera yet. That disclaimer, I decided to try the lens out on stars. But these are from my Silicon Valley backyard with tons of light pollution, so keep that in mind too please!
Basically, as full images they look pretty decent, but zooming into 100% you definitely see the optical warts. I doubt diehard astro enthusiasts will fawn much over this lens. However, I think it's definitely useable for the occasional landscape shooter who happens to already own it and wants to grab the occasional general astro landscape. Basically that was my interest in this test and my takeaway is this lens will serve that purpose just fine for me. There also may be lens copy variation and this may be a bad copy, IDK... The reality is 12 through 16 all pretty much looked like what I'm posting below. In fact I had to look at exif to know which focal I was at when viewing at 100%. The 18 to 20 range shows a little bit more coma at the corners. This could be due to the added focal magnification or simply worse coma or both. Again, this is not visible in the full image at normal viewing distances. Below is a full-frame image and 3 100% crops as labeled. Also these are all 2048px crops so make sure to view them at that size as browsers will enlarge images in this forum.
PS Edit: For whatever reason there appears to be some color artifacting/banding in the full jpeg as posted here that isn't in my original, I've triple checked it and even re-posted, so can't explain that.
Full image
ILCE-7RM6TAMRON 12-20mm F2.8 A084 E lens16mmf/2.84s3200 ISO0.0 EV
Okay, one more I had to share just for giggles. I was out testing all my lenses on the A7R6 body this morning, and this was the very first capture using the Tamron 12-20 at 12mm wide open. Upon reviewing it, I saw this FYI, full is sized to 2048 wide while crop is sized to 4056 to better see it. (Yes, that's a dragonfly )
full image at 2048 wide
ILCE-7RM6TAMRON 12-20mm F2.8 A084 E lens12mmf/2.81/3200s100 ISO0.0 EV
Douglas L wrote:
Thanks for the report! I thought the Tamron 12-20 would be shorter than the Sony 20-70. I didn't compare the specs of the two. Would love to see some shots of sunstar. it may replace my Vogtlander 12, 15 and 21 f1.4 if it's good enough.
Douglas, sorry this took a bit. This from my backyard this morning. I took multiple zoom focals and apertures from f10 through 16 and they all pretty much look just like this one at 12mm f16. My guess is it would probably still sunstar at f8, but I didn't specifically check for that. I know from past lenses, using the max aperture allows for a bit better cleaning up the edges of the star, but I didn't really see much difference in them between f10 and 16. For this image, my focus point was on the tree the sun is shining through, and in post I did correct for some of the geometric lean distortion; and that tweak did not significantly alter the sunstar. All FWIW, hope it helps!
PS note: I'm actually impressed by the flare control in this lens, especially here at its widest focal. Obviously there is flare, but it appears very well controlled IMHO.
PPS: For giggles I am adding a second version that has has some clarity and de-hazing done in addition to the above -- the above was zeroed on clarity.
Comments appreciated. FTR I prefer the de-hazed version myself.
ILCE-7CM2TAMRON 12-20mm F2.8 A084 E lens12mmf/16.01/30s250 ISO0.0 EV
I am considering this lens and having it replace my 14gm. Size is roughly the same so in the bag its no difference, however it gives the zoom opportunity to 20 which I like to shoot and then if need go to the 12.
I love the 14 but this is very intriguing
Any more thoughts on this lens or thoughts on my decision to switch?
eriet30 wrote:
I am considering this lens and having it replace my 14gm. Size is roughly the same so in the bag its no difference, however it gives the zoom opportunity to 20 which I like to shoot and then if need go to the 12.
I love the 14 but this is very intriguing
Any more thoughts on this lens or thoughts on my decision to switch?
I have recently tested mine out in more demanding situations. I am absolutely keeping it. The only nits of note are occasional bits of unwanted flare, which of course is not uncommon in ultrawide lenses. The other is it shows a bit of field curvature, but is remarkably sharp to the corners across the range, and of course DoF at f5.6 essentially eliminates it in landscape style shots.
I have also taken a few astro shots with it. My guess here is it’s inferior to your 14GM. In the corners if you zoom in to 100%, you see some coma and astigmatism, but regardless it does still render quite well at normal image magnifications. So if you are doing a lot of astro, I’d keep the 14 as it’s probably a bit better here and also 1-1/3rd stops faster which is significant for astro.
If you’re looking for a really versatile doitall ultrawide zoom, I think this lens is tough to beat. I will add that the difference between 14mm and 12mm FoV is pretty remarkable. While only a 2mm difference, I need to remember that’s about a 17% difference, or the same difference as 24mm is to 28mm… Oh, final note is the latest updates for Adobe does have the correction profiles for it.
Jack Flesher wrote:
I have recently tested mine out in more demanding situations. I am absolutely keeping it. The only nits of note are occasional bits of unwanted flare, which of course is not uncommon in ultrawide lenses. The other is it shows a bit of field curvature, but is remarkably sharp to the corners across the range, and of course DoF at f5.6 essentially eliminates it in landscape style shots.
I have also taken a few astro shots with it. My guess here is it’s inferior to your 14GM. In the corners if you zoom in to 100%, you see some and astigmatism, but regardless it does still render quite well at normal image magnifications. So if you are do a lot of astro, I’d keep the 14 as it’s probably a bit better here and also 1-1/3rd stops faster which is significant for astro.
If you’re looking for a really versatile doitall ultrawide zoom, I think this lens is tough to beat. I will add that the difference between 14mm and 12mm FoV is pretty remarkable. While only a 2mm difference, I need to remember that’s about a 17% difference, or the same difference as 24mm is to 28mm… Oh, final note is the latest updates for Adobe does have the correction profiles for it. ...Show more →
Thank you that is helpful. I no longer am the pixel peeper I once was I am more about the shot now, however I am ADHD and so I overthink the whole. "I have the quality lens why am I changing" vs the "hey this might help me shoot better shots in the situation in the field" thing.
FYI, full is sized to 2048 wide while crop is sized to 4056 to better see it. (Yes, that's a dragonfly 
) 
