p.38 #1 · Official: Tamron 35-150mm F/2-2.8 Di III VXD (Model A058)
zeitlos wrote:
I am not an expert (basically far from being one), so can you explain this technically?
The above post explains this nicely. I am not an expert myself, but I believe a lens might be intentionally or unintentionally made to perform better at some distances. For example, a macro lens should be the sharpest near the MFD, and may not be the best when focused at a distant target. A telephoto lens may have certain useful applications at the MFD (the 100-400GM is an excellent example of a semi-macro lens), however their main application is arguably to take pictures of distant subjects. From this practical point of view, the performance of the Tamron at the long end would be better tested when focused at the suitably long distances.
Mark Alhadeff described the performance of the Tamron at 150 mm and F2.8 and 4 as "very good"; in his experience, the lens became excellent only at F5.6. This seems to be similar to what I see in the pictures presented above. I don't see this as a problem myself, when thinking about using this lens while travelling when I would often have the aperture in the 5.6 - 8 -11 range for landscapes or cityscapes.
p.38 #2 · Official: Tamron 35-150mm F/2-2.8 Di III VXD (Model A058)
This is true, there are some lenses which are "better" aka sharper at certain distances. It's not a common thing but it is a thing.
It's one of the reason why nowadays there is a disscusion if "chart" tests should be used at all in testing lenses. However the other side argues that you can almost never have repeatable "real world" test. So it's kinda a stalemate.
Also keep in mind that resolution of the camera matters alot in lens sharpness testing (if the lens is sharp enough to begin with). For the sake of this conversation if lens X is:
"very good" on 61 Mpix camera (A7R IV) it will be
"excelent" on 42 Mpix camera (A7R III) and if you go even lower it will be
"outstanding" on 24 Mpix camera (A7 III/A7C)
However i never seen it this manifest in a way like above (haze) so that makes think that his copy of the lens is less than stellar.
p.38 #3 · Official: Tamron 35-150mm F/2-2.8 Di III VXD (Model A058)
I think this is perfectly normal for a lens to show a visible improvement when stopping 1 - 2 stops from the widest aperture. Take one of the best primes, e.g. the 35mm F1.4 GM, and you should see a major improvement in image quality by F2.8. It might be simply unrealistic to expect a 35-150 mm zoom to exhibit excellent sharpness at 150 mm when wide open. From my reading, I understand that such zooms are generally expected to be optically somewhat weak at the long end. I remember, for example, reading how Roger Cicala was surprised by the (unexpected) sharpness of the 24-105 mm F4 G lens at 105 mm. There need to be more testing done at the 150 mm end. I am thinking about ordering this Tamron lens, and I would not be alarmed should I find that the lens must be closed to F5.6 at 150 mm for the best performance for landscapes. For portraits at 150 mm, which tend to fill the frame, the difference between F2.8 and 5.6 may not be visible, or can be insignificant.
p.38 #4 · Official: Tamron 35-150mm F/2-2.8 Di III VXD (Model A058)
Immortal wrote:
This is true, there are some lenses which are "better" aka sharper at certain distances. It's not a common thing but it is a thing.
It's one of the reason why nowadays there is a disscusion if "chart" tests should be used at all in testing lenses. However the other side argues that you can almost never have repeatable "real world" test. So it's kinda a stalemate.
Also keep in mind that resolution of the camera matters alot in lens sharpness testing (if the lens is sharp enough to begin with). For the sake of this conversation if lens X is:
"very good" on 61 Mpix camera (A7R IV) it will be
"excelent" on 42 Mpix camera (A7R III) and if you go even lower it will be
"outstanding" on 24 Mpix camera (A7 III/A7C)
However i never seen it this manifest in a way like above (haze) so that makes think that his copy of the lens is less than stellar....Show more →
The thing about Marc's testing approach is that it's very subjective (he also uses a rather close bookshelf for this, no? ), which not always lead to consistent (with others) results, e.g. AFAIR 14-24DN is "only" very good according to him. I enjoy his reviews but that part makes me less of a fan .
He labels them "very good" or "excellent", but doesn't show the difference between the two. It would be interesting to see the degradation going from 61MP to 50MP, which I honestly doubt is that big of a jump.
I'll gladly test the Tamron against 100-400GM on the long end and against 24-70DN in the mid range (both marked as "excellent"), if I ever get one .
p.38 #5 · Official: Tamron 35-150mm F/2-2.8 Di III VXD (Model A058)
I did two quick test shot rows at the long end of 150mm. To be honest, in my (subjective) point of view it confirms my findings with the test charts so far.
100% magnification:
and
FYI: If you want, you can find all files in full size here:
p.38 #7 · Official: Tamron 35-150mm F/2-2.8 Di III VXD (Model A058)
My preliminary uses, my copy is very sharp and focuses very fast for event work. I’m going to put it thru a grueling test tonight for a boxing match. And will report back
p.38 #9 · Official: Tamron 35-150mm F/2-2.8 Di III VXD (Model A058)
ruthenium wrote:
Let's see more comparisons at 100 - 150 mm of the images of some relatively distant targets. These can be more revealing of the behavior of this lens than images of charts.
After some testing, I can say that all my findings in the charts (the good, the bad) are mirrored in the distant shots I took. So I wouldn't generally say that charts don't work. At least for now I've come to the same conclusions.
p.38 #10 · Official: Tamron 35-150mm F/2-2.8 Di III VXD (Model A058)
ruthenium wrote:
I think this is perfectly normal for a lens to show a visible improvement when stopping 1 - 2 stops from the widest aperture. Take one of the best primes, e.g. the 35mm F1.4 GM, and you should see a major improvement in image quality by F2.8. It might be simply unrealistic to expect a 35-150 mm zoom to exhibit excellent sharpness at 150 mm when wide open. From my reading, I understand that such zooms are generally expected to be optically somewhat weak at the long end. I remember, for example, reading how Roger Cicala was surprised by the (unexpected) sharpness of the 24-105 mm F4 G lens at 105 mm. There need to be more testing done at the 150 mm end. I am thinking about ordering this Tamron lens, and I would not be alarmed should I find that the lens must be closed to F5.6 at 150 mm for the best performance for landscapes. For portraits at 150 mm, which tend to fill the frame, the difference between F2.8 and 5.6 may not be visible, or can be insignificant....Show more →
That's true, however we're talking here about a specific situation, specific lens. Obviously almost all lenses show some improvment when stopping down 1-2 stops from the widest aperture. However in this case, that haze isn't normal it's either a dud lens copy or he was very unlucky and cought heat distortion (since his shoots at home look much better at F2.8). I don't see any other reasonable explanation.
j4nu wrote:
The thing about Marc's testing approach is that it's very subjective (he also uses a rather close bookshelf for this, no? ), which not always lead to consistent (with others) results, e.g. AFAIR 14-24DN is "only" very good according to him. I enjoy his reviews but that part makes me less of a fan .
He labels them "very good" or "excellent", but doesn't show the difference between the two. It would be interesting to see the degradation going from 61MP to 50MP, which I honestly doubt is that big of a jump.
I'll gladly test the Tamron against 100-400GM on the long end and against 24-70DN in the mid range (both marked as "excellent"), if I ever get one ....Show more →
I'm not really a fan of Marc tests. I have a respect for the work he puts in it however for me - when i test my lenses very extensively i often have different results than him and much closer to results of people like Dustin Abbot which i like to watch.
The point in that comment using Marcs metric was to emphasize that sensor resolution matters in lens testing. There is quite a big difference in how much flaws in a lens you will see on 24 Mpix camera vs 61 Mpix camera or even 42 Mpix. Lens X can be (for the sake of consistency) excelent on A7 III a cross the frame but "only" very good at A7R IV. As for your point - yes the difference in A1 vs A7R IV resolution in lens testing is very small (you can spot it in pixel peeping mode with certain lenses but in a real world images unless you print in billboard size there will be no difference).
zeitlos wrote:
After some testing, I can say that all my findings in the charts (the good, the bad) are mirrored in the distant shots I took. So I wouldn't generally say that charts don't work. At least for now I've come to the same conclusions.
Your copy of the lens is very good, nothing really to complain about here.
p.38 #11 · Official: Tamron 35-150mm F/2-2.8 Di III VXD (Model A058)
Just a quick update. Just compared my copy with a copy at a local retailer. It is indeed the lens that was a dud. My new copy has a significantly tighter lockup on the body mount (first copy had some play), and the haze is entirely absent at 150mm at f/2.8. Needless to say my initial copy will be going back. Given that, I’ll likely entirely redo my comparison test analysis with my Sigma 24-70 and 100-400GM for those interested.
p.38 #12 · Official: Tamron 35-150mm F/2-2.8 Di III VXD (Model A058)
I’m glad you were able to clarify things quickly because it can be so frustrating. You spent a lot of money for this lens and started to like it. It would have been a shame if there was no solution.
Will you ask for an exchange from the dealer you bought your first copy? Or did you buy from your local retailer to make sure your copy is okay this time? Which again confirms that we should also spend money at local dealers because it also benefits our needs.
p.38 #14 · Official: Tamron 35-150mm F/2-2.8 Di III VXD (Model A058)
ajamils wrote:
35-150mm?? Isn't it kinda weird FL? Neither wide not tele?
Personally I think this will work better than a 70-200 for most events, 150 is really not that far away from 200, I will go 16-35 + 35-150 over 24-70 +70-200 anytime, I only wish this is a 2.8 fixed so it's a little smaller lighter and cheaper, but I will buy one just for the great focal range.
p.38 #17 · Official: Tamron 35-150mm F/2-2.8 Di III VXD (Model A058)
j4nu wrote:
I'd say the whole point of this lens is starting at f2...
There are already multiple slower options available in similar range: 24-105 f/4, 28-200 f/2.8-5.6 ...
I personally think it will be even better if it's a fixed 2.8, I mean if shooting slow stuff it's OK, but if shooting something fast when we zoom the f stop change will change the exposure, yes I can put it to 2.8, but the f2-2.8 design just made this lens bigger heavier and cost more.
p.38 #18 · Official: Tamron 35-150mm F/2-2.8 Di III VXD (Model A058)
I don't think 3rd party lenses have worse resale value than Sony GM.
The 24-70GM is about 1400 used right now which is 900 down which is 40%, Tamron 28-75 is in about same % used right now, and Sigma 24-70 is at better % than both of them.
70-200GM is about 1700 used right now which is 900 down which is 35%, Tamron 70-180 is selling at better % used right now.
Sigma 85DN is doing a lot better than the 85GM resale, I know it's a much newer and better lens.
24GM dropped like 35% too.
12-24GM lost 30%, Sigma 14-24DN about the same %
Only some of the super new GM like 14GM and 50GM hold it's value really well now, but don't think it will hold the same kind of value after another 2 to 3 years.
So I really don't think the resale value is something that should keep people away from 3rd party lenses.
If people know it's a great lens it will resale well.
Maxxus46 wrote:
Maybe but it's still a third party lense and will have less value at resale. Also, it will not be able to perform above 15FPS for us A1 and A9 users. I want this lens to be great like the 70-180. But I would have issue spending $1800 on it knowing resale would be poor compared to Sony glass.
p.38 #20 · Official: Tamron 35-150mm F/2-2.8 Di III VXD (Model A058)
EdwardDye wrote:
I personally think it will be even better if it's a fixed 2.8, I mean if shooting slow stuff it's OK, but if shooting something fast when we zoom the f stop change will change the exposure, yes I can put it to 2.8, but the f2-2.8 design just made this lens bigger heavier and cost more.
Sorry, no offense meant, I simply wonder if this is a correct assumption that the lens could be more compact if it had the constant F2.8 aperture. Theoretically, the diameter of the aperture when fully open is the focal length over the F number. If this is correct, then the diameter of the lens is mostly due to the F2.8 at 150 mm, not due to F2 at 35mm. I know little about the lens design, thus this is merely a question whether the size of the Tamron zoom might be due to factors other than the F2 at 35mm, for example due to the focal range it covers, all the glass inside to correct for the aberrations, the focus drive mechanism, etc.
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