First Thoughts on Tamron 24-70 F2.8

[Geoff F]

In some other posts, I mentioned that my Canon 24-105 had stopped working and I had been researching alternatives before deciding what to do next. I didn't restrict myself with budget considerations as I was just looking.

There are quite a few alternatives around this size range. 24 mm is wide enough for me but I do wonder if 70 mm will be a little short for me. But I do also have the Canon 70-200 F4.

To be honest, I had tended to regard Tamron as being a budget price lens manufacturer so I was initially surprised to see this lens being reviewed alongside similar Canon L lenses.

But all the reviews highly recommended it. In fact some suggested that because it was a stabilised lens (VC) it was a better bet under some shooting conditions.

So I purchased one for just over £800 which seemed to be a good deal.

Since it arrived we have had mostly dull wet weather so I have only done a few test shots so far.

It is certainly a large and heavy lens, with 82 mm diameter lens. All plastic construction, but it appears to be good high impact resistant and everything is very firm at the moment.

The UV filter was very stiff to screw in, I don't know if this was due to the lens or filter thread, and I was rather nervous about working it back and forth until it fully tightened. OK now though.

Most reports mentioned that the switches for AF/Manual and VC on/off were difficult to use. Well they are stiff and I wouldn't want to move them with just a finger nail, but I found there is a knack to getting a straight finger behind or in front of the switch. It then moves with no problem.

The manual focusing ring is rather narrow and I do find that I have to think about where it is situated. Although this will probably become second nature after some use.

The zoom rotation direction is the opposite way to my Canon lenses, but to be honest, the Tamron direction appears more logical. Clockwise to zoom larger.

There is a lock switch to prevent zoom creep while the lens is being carried. Without this, it will eventually creep forward with vigourous shaking but the zoom is reasonable stiff.

The lens cap and hood are well constructed and fit snugly without any rattling.

AF is quick and quiet; and fast enough for me.

So far no real faults but now to my initial test thoughts which I will upload in another post.

[Geoff F]

At F2.8 the results were disappointingly soft; but this considerably improved by F4 and at F8 to F11 sharpness was good. There was a little bit of reduction at F16, which is to be expected.

Distortion is very good, at least around the middle settings; much better than my previous Canon 24-105 L and fractionally better than the 70-200. But this isn't a fair comparison as we are working with opposite ends of the zoom range.

I tried some comparison shots against my 70-200 L F4 at 70 mm, which isn't really a true or fair comparison but that will be a decision which I may often have to make during shooting.

At F11, the 70-200 seemed marginally better but much of this seemed to be due to better contrast which could be due to the long lens hood. I then shot again with -1/3 exposure compensation for the Tamron and I couldn't see any difference.

However at F4 the Tamron was considerably sharper.

Shooting some straight lines at 1/500 F5 Iso 100 on a tripod, 44 mm. The light angle wasn't good but I couldn't find anything better.



A flower in the rain. Not the angle or lighting that I would have ideally chosen but it makes a good test. 1/250 F11 Iso 200 on tripod. 57 mm



A bit of landscape under fairly dull light. The foreground is a little too close and it was windy. The far distance was 2 miles. 1/500 F8 Iso 200 70 mm



Some more flowers 1/320 F11 Iso 100 65 mm.





The minimum focusing distance is 8 inches so this should make a fairly good flower lens. I also tried a few handheld flowers and was surprised by how good they came out.

These examples were shot Raw and have only had a little basic editing.

After a few days and a couple of hundred shots I will be able to give a better opinion; but at the moment it looks good. Providing 70 mm is sufficient for me. I won't be shooting wide open at F2.8 due to the softness but I rarely use F4 with my other lenses so that won't be a problem for me.

[Brev00]

Good initial review. Take your time with the lens. I get the impression you are to some extent rushing to judgment. These pics all seem fine as test shots, but I would rather see your best when you get beyond the testing: images that you would like to frame. I am also curious about your images at 2.8. Softness wide open with a lens that costs some serious coin even if not as much as the Canon would be an issue for me. You are paying for the speed after all. So, show some of the 2.8 shots for the sake of getting a sense of the lens' limitations. I know such softness would be a concern for me. Thanks for your efforts so far!

I kinda like the greenhouse shot even with the difficult lighting.

[Adrian]

I am inclined to agree that a large part of the reason for paying a high price for a fast lens is to be able to use it wide open. If it is soft at f2.8, I would return it. Try the Canon 24-70 f2.8L Mk II: it is not soft wide open. It is a bit more expensive though.

[PhotomanJohn]

I would add that one can often get past some of the softness in PP and come up with an acceptable image. I would like to try that on some of your f/2.8 examples.

John

[Geoff F]

OK, I have now done more tests at 24 mm and F2.8 which should give maximum softness problems.

Possibly the focus depth is much shallower than I was expecting; also the centre is noticeably sharper than the corners.

Firstly, one of those lens focus charts but I stuck it on a wall and shot at 90 degrees. Focus point was the Focus Here line. On tripod with cable release, shot Raw with no editing except a crop. Poor indoor lighting, but that is where a F2.8 lens would be most useful.

F2.8



F8



Another test subject, Arnold, shot at 24 mm F2.8. The focus point was his eyes.



And again at F8.



Took the lens on a wildlife shoot today but only shot a bit of fungi before it started to rain; and it is still raining now!

I will certainly give it a good testing on real life shots next week, if we get some sunshine and do a full report afterwards.

[Geoff F]

Incidentally, the main review which persuaded me to purchase this lens is here for the Tamron

http://www.photozone.de/canon_eos_ff...on2470f28eosff

And here for the Canon alternatives

http://www.photozone.de/canon_eos_ff...on2470f28mk2ff

[Brev00]

That is more of a front/back focus check. You don't want to do the whole slant shot approach for sharpness. Just get one of those resolution charts--google and download, make 5 copies, and tape to a some white poster board (one in each corner and one in the middle). Then fill the frame and shoot away with your good tripod technique. You want to compare the resolution and contrast in center shots as well as edges and corners. You need a flat surface for that--the chart is parallel to your sensor in the required test. There seems to be an exposure difference in these two shots and the area of focus is hard to really evaluate with its location near the edge. Given the limited nature of this test, the 2.8 looks ok to me.

[Geoff F]

Yes, I didn't have any resolution chart so this was the best I could easily find.

Did some more general lens checks today.

Whether using stabilisation is detrimental to image quality when using faster shutter speeds is something which occasionally gets discussed. So I did some checks and couldn't see any difference.

It is recommended to turn off the VC stabilisation on this lens when using a tripod. I tested both ways but couldn't see any difference either way.

At F2.8 it did seem that manual focus was fractionally better than AF. But with narrow focus depth it is easy for AF to be slightly out even when on fairly firm subjects. Which is why I prefer to manually focus with macro shots.

Most of my testing was being done on fairly well lit subjects with quite high shutter speeds. So today I had a go at a darker subject, which is more suitable for a faster lens.

F3.2 did seem noticeably sharper than fully open at F2.8.

While shooting, using a tripod and a sundial as a subject, a visitor appeared to remind me that the birdtable needed topping up.



This is a crop but otherwise it is an unedited Raw file. 1/125 F3.2.

And the final edited version.

[Adrian]

The robin does not appear perfectly sharp?

[Geoff F]

I think that is partly due to the fact that it is a juvenile and has slightly 'unusual and softer head colouration'. I can see feather detail in a 7 x 5 ins print.

And it was AF. Ideally, if I had set out for a photo of the bird, I would have used manual focus for a shot like this.

Certainly not the camera settings I would have used for a serious bird shot though; but an interesting unexpected subject for a lens test. My intended subject was the sundial.

I will try a few more test charts when I get sufficient time later this week and see how they work out. The lens certainly seems OK at F4 and above.