Tamron 17-50mm f2.8 XR Di II LD


iceblinker

Link Posted 04/01/2010 - 18:57
These are all with the Tamron 17-50 on K-7 at f2.8, 1:1 with Silkypix RAW sharpening but no USM:

Centre @ 50mm, ISO 100:






Near corner of frame @ 17mm, ISO 3200 (sorry!):


~Pete
Last Edited by iceblinker on 04/01/2010 - 19:01

Greytop

Link Posted 04/01/2010 - 19:41
Thanks Mike and Pete, seems that it might possibly be a better performer than the the 16-50 wide open (at least in the boarders). Centre performance of the 16-50 is still good to excellent at f/2.8 and the whole frame sharpens nicely by around f/4 to f/5 or thereabouts.
I might even consider one these 17-50s if I spot used one at a reasonable price
Regards Huw

flickr

iceblinker

Link Posted 04/01/2010 - 19:53
Used ones rarely come up on eBay The owners must like them too much
~Pete

mikew

Link Posted 04/01/2010 - 20:04
I bought mine on impulse as I was fed up with the kit lens and its non constant aperture. It was an eye opener for performance. I will use it at any aperture in full confidence.

One thing that does seem to be the case is that these lenses are prone to needing AF adjustment to deliver their very best.

Mike
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You can see some of my shots at my Flickr account.

thoughton

Link Posted 05/01/2010 - 08:32
johnriley wrote:
You asked for an honest reply, and to be honest the image isn't really very sharp.

John - I don't think anyone expected you to find it sharp, since it isn't made by Pentax

Mike - that seems quite impressive for a corner, although I keep wondering what it is?? Grey wallpaper? I find it quite hard to judge sharpness from that photo because I'm not sure what the subject is.
Tim
AF - Pentax K5, Sigma 10-20/4-5.6, Tamron 17-50/2.8, Sigma 30/1.4, Sigma 70-200/2.8, Tamron 70-300/4-5.6
MF - Vivitar CF 28/2.8, Tamron AD2 90/2.5, MTO 1000/11
Stuff - Metz 58 AF1, Cactus v4, Nikon SB24, Raynox 150, Sigma 1.4x TC, Sigma 2x TC, Kenko 2x macro TC, Redsnapper 283 tripod, iMac 27, Macbook Pro 17, iPad, iPhone 3G
Flickr Fluidr PPG Street Portfolio site
Feel free to edit any of my posted photos! If I post a photo for critique, I want brutal honesty. If you don't like it, please say so and tell me why!

johnriley

Link Posted 05/01/2010 - 08:40
Quote:
John - I don't think anyone expected you to find it sharp, since it isn't made by Pentax

Perhaps, but do you think it's sharp? Is it sharp compared to other lenses you have?
Best regards, John

thoughton

Link Posted 05/01/2010 - 08:58
Yes, I do think it is sharp! I haven't done any formal testing but just from normal photography it seems to rival what I consider to be my sharpest lenses (probably the 50, 85 or 90mm).
Tim
AF - Pentax K5, Sigma 10-20/4-5.6, Tamron 17-50/2.8, Sigma 30/1.4, Sigma 70-200/2.8, Tamron 70-300/4-5.6
MF - Vivitar CF 28/2.8, Tamron AD2 90/2.5, MTO 1000/11
Stuff - Metz 58 AF1, Cactus v4, Nikon SB24, Raynox 150, Sigma 1.4x TC, Sigma 2x TC, Kenko 2x macro TC, Redsnapper 283 tripod, iMac 27, Macbook Pro 17, iPad, iPhone 3G
Flickr Fluidr PPG Street Portfolio site
Feel free to edit any of my posted photos! If I post a photo for critique, I want brutal honesty. If you don't like it, please say so and tell me why!

mikew

Link Posted 05/01/2010 - 09:24
Tim: It's a cloth roof of a classic car with water droplets on it.

John: When I got the Tamron it blew me away with how sharp it was but I only had the kit lens and Pentax 50-200 to compare. Now I have some Ltd's and a 35 f2 I don't think it's quite as sharp but then I don't think I have seen a zoom to match the 35 f2.

As I said the only reason I don't use it more is bulk. OTOH when I went to Barcelona it was the only lens I took and it was just fine.

Mike
---------------------------------------------------

You can see some of my shots at my Flickr account.

iceblinker

Link Posted 05/01/2010 - 13:31
There have been various doubts and criticisms raised about the Tamron 17-50mm - including AF error and underexposure - but sharpness is not usually one of them.

It is generally considered to be very sharp by its users and reviewers. If you see a soft image from it, it's probably due to the way it's been processed or because it wasn't focused or held still properly.

The first image in this thread does look soft, and is not a great advert as it stands, but I expect any unsharpened image at 100% to look soft.

The images I posted show what detail the lens can capture even at F2.8. Consider how heavily cropped the pictures are and look at the bird's tiny claws.
~Pete

cabstar

Link Posted 05/01/2010 - 16:41
Love this lens, I have to agree it is sharp for a zoom lens. Certainly put me of buying 16-50mm for a whilst yet!

Non cropped but resized.





PPG Wedding photography Flickr
Concert photography

Currently on a Pentax hiatus until an FF Pentax is released

Braunton

Link Posted 09/01/2010 - 10:29
Interesting comments on here about the Tamron SP 17-50. I bought one of these when I purchased my K20D 18 months ago, and am generally very pleased with its build and image quality. Various people have mentioned the need for AF adjustment, and I have noticed on some images (generally taken at wider than f5) that it is less than sharp on the RH side, but fine on the LH side. This suggests that I need to adjust. Can someone talk me through, in words of one syllable, how this should be done. Thanks

iceblinker

Link Posted 09/01/2010 - 10:55
If it's to a significant degree, and when facing square-on to a flat subject, being much softer on one side than the other would indicate a fault with the lens: a centering defect. That would need to be fixed or replaced by Tamron if it's bad.

You should check that really is happening first of all: that the RH side is consistently softer than the left, even the left and right of the subject are at the same distance from the lens.

Adjustments that affect the whole of the frame are done via AF Adjustment near the end of the Custom menu:

Set the zoom to 50mm and the aperture to F2.8.

Using a triod, or a shutter speed fast enough to eliminate shake, take a shot of something still at a typical distance with good light and contrast.

Then enter an adjustment of -5 and take another shot. Same again with -10, +5 and +10.

Repeat the whole thing with different subjects and different zoom settings. Examine the images and decide which is generaly the sharpest setting. Repeat with finer adjustments if you like.

Focus charts are tricky to use and tend to test the lens for close focusing distances, so only use one if that's what you want to calibrate for. AF can behave differently at longer distances.
~Pete
Last Edited by iceblinker on 09/01/2010 - 11:10

smc

Link Posted 09/01/2010 - 17:37
thoughton wrote:
No problem, I'll be working at home all day tomorrow. perfect chance to skive off

I'm not even sure why I started this thread It was late and I'd had a few. I was just going over some photos from the day before (drunkenly marvelling at my photographic prowess ) and it occurred to me that the Tamron 17-50 doesn't get enough love on this forum!

Some people compain about the sharpness, but that is not the only test of a lens: the rendering or drawing of this lens is apprently very attractive. It certainly did a good job with your photo.

Braunton

Link Posted 14/01/2010 - 01:04
thanks Pete, I`ll give that a try.

Stu-D

Link Posted 14/01/2010 - 16:10
I have read a few reports now that say that the Tamron 17-50 has focussing issues, being front focussing at one end of the zoom range and rear focussing at the other end. I dont know if this is confined to a particular period in time, or a problem with particular examples, but it does put me off buying this lens. If it sharp but doesnt focus well, then the results are not going to be great.

I have been thinking also about the Sigma 17-70 - it doesnt have the speed at the longer focal length (but I have a 50mm prime lens) and I havent read anything of the focussing issues, plus it has a larger range and better macro abilities (although I appreciate that neither are proper macro lenses)

I must admit I have got some pretty good results from the 18-55 kit lens, so a part of me thinks why bother?

Any comments, particularly on the focussing issue, are most welcome. I have a K20D, so I know it has the ability to adjust the auto-focus, but unsure whether it would cope with a lens with both front and rear focus issues (at each end of the range).

Cheers

Stuart
K20D | FA 50mm f1.4 | Sigma 17-70mm | DA 18-55mm kit | DA 50-200mm
Last Edited by Stu-D on 14/01/2010 - 16:14
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