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View Full Version : quick thoughts on tamron 17-50


phatkid77
09-02-2006, 04:42 AM
well i picked up the lens yesterday after work... got off about 30 pics of various aperatures... i will take some tonite after work and post findings, but first thoughts are im not too impressed at f2.8 when viewed on the LCD..

1. i like the feel of the knurled lens and the weight
2. focus seemed snappy and not loud like others report
i took some pics of my driver licence at ISO 1000 f2.8 ss1/250 and my name looks like a shot with the 70-200 without VR, i kept the settings the same and shot 4/5.6/ 7.1 and f9, to be honest it didnt appear to get real sharp until f7.1, which im not too happy about..

i am gunna search fo a focus chart i think ive read about and print it off and do some comparos for you all...

stay tuned...

any tips to test sharpness..like if i print the focus test chart for the D70 can i shoot hand held str8 on to guage sharpness...im not looking for backfocusing??? nor do i currently own a tripod....
thanks

coldrain
09-02-2006, 05:31 AM
The 17-50 is a reasonably sharp lens even at f2.8, so my guess is that it does not focus all that accurately on your D200. "back focussing" is nothing more than inaccurate judgement of focus by the camera (or camera/lens combination). Some people do not understand that it is not the lens that determines focus, but that it is always the camera doing that.

K1W1
09-02-2006, 05:31 AM
I thought about this lens but I decided that it was basically a con.
The f2.8 only works at 17mm and as soon as you zoom you loose the low light capability. The images I have seen so far do not look much better than the D50 kit 18-55 so I have decided to stick with that lens until I can justify a "pro" product in that range.

coldrain
09-02-2006, 05:34 AM
I thought about this lens but I decided that it was basically a con.
The f2.8 only works at 17mm and as soon as you zoom you loose the low light capability. The images I have seen so far do not look much better than the D50 kit 18-55 so I have decided to stick with that lens until I can justify a "pro" product in that range.
That is not true at all, it is a f2.8 lens over the entire focal range and it is quite a bit better than the Nikon kit lenses in areas.

I think you are confusing it with the Sigma 17-70 f2.8-4.5.

K1W1
09-02-2006, 05:36 AM
That is not true at all, it is a f2.8 lens over the entire focal range and it is quite a bit better than the Nikon kit lenses in areas.

I think you are confusing it with the Sigma 17-70 f2.8-4.5.

You are correct.
I retract my comment.

phatkid77
09-02-2006, 05:40 AM
well, ill try and get one more copy in and the nikkor.... which ever one is sharper i will keep.... god i hope the tammy is.....lol

mals

coldrain
09-02-2006, 05:55 AM
Just test what is the problem. Your idea of checking is focus is on the rights pot is a very good idea, so do that first.

If it is not on the right spot, and that is what causes the unsharpness on the subject, I doubt getting another Tamron 17-50 f2.8 copy will help much, since it has no AF motor of its own, and does nt have any influence on the "finding the best contrast" AF sequence of your camera.

So... if the Tammy just cant be used reliably, choose a different lens or a different camera. My guess is that choosing a different lens in that case is preferrable ;).

Other options are of course the Sigma 18-50 f2.8 (the test of the Sigma did not show any AF problem), the to be introduced still Tokina 16-50 F2.8 (which just might be a great lens), the expensive Nikon 17-55 f2.8 (around 1200$).

Other lenses that don't quite go as wide that are recommendable are the Tamron 28-75 f2.8, the Sigma 24-70 f2.8 and the very expensive Nikon 28-70 f2.8.
All three should work well on your camera.

Those are your best options, if the problem is the actual focussing.

phatkid77
09-02-2006, 06:08 AM
well, i wanted the 24-70 and what not, but figured for weddings and such the 17-50 is the better choice...
im not sure its and AF accuracy issue as much as a sharpness issue, because as i said the writing was alot crisper at f7 than f2.8, but maybe its more accurate thus sharp at f7 than f2.8

i will test the tamron at f3.5 18mm VS the sigma 18-200 at f3.5 and 18mm to gauge sharpness there too...

will definitely play around tonite.. when i go to the shop on tues i will look at the sigma as well..

mals

coldrain
09-02-2006, 06:12 AM
At f2.8 the depth of field is a LOT smaller than at f7. So if your camera/lens combination is not too accurate on the best focus position, that will show a LOT more at f2.8 than at f7.

So, do test the focus position (more than once) and it would maybe be helpful if you show 100% crops of the areas that are supposed to be in focus ( the part you focussed on). Good luck!

Oh, and you can also still consider the Sigma 18-50 f2.8... It is close to the tamron you chose, and really performs quite well. That will give you your wanted extra width (if actually needed)... I think there are at least two forum members that are happy with that 18-50 f2.8 Sigma on their D50s.

erichlund
09-02-2006, 12:37 PM
...and, while you are testing focus, you might just want to turn autofocus off, and see how well the lens can focus manually, especially in ranges that are giving you trouble. If you have the same problem as when autofocusing, you've just eliminated the camera as the issue.

Esoterra
09-02-2006, 06:40 PM
well, i wanted the 24-70 and what not, but figured for weddings and such the 17-50 is the better choice...
im not sure its and AF accuracy issue as much as a sharpness issue, because as i said the writing was alot crisper at f7 than f2.8, but maybe its more accurate thus sharp at f7 than f2.8

i will test the tamron at f3.5 18mm VS the sigma 18-200 at f3.5 and 18mm to gauge sharpness there too...

will definitely play around tonite.. when i go to the shop on tues i will look at the sigma as well..

mals

Phat... I use the Sigma 24-70 f/2.8 as my primary lens at all my weddings and have never had problems framing- moving my body to frame the image wasnt a problem though- the 24-70mm range works great. I do have a 12-24mm and use that as well. Have you considered the 24-70mm range and adding on a 12-24mm?

phatkid77
09-02-2006, 07:25 PM
yes i did, but figured i could crop the 50mm if need be... i will mull it over for the next couple days... as it turns out im an idiot...

i switched from matrix to spot metering and it made BIG difference??? i will put up examples.... kinda confused but i do feel abit better..

phats

coldrain
09-03-2006, 02:37 AM
yes i did, but figured i could crop the 50mm if need be... i will mull it over for the next couple days... as it turns out im an idiot...

i switched from matrix to spot metering and it made BIG difference??? i will put up examples.... kinda confused but i do feel abit better..

phats
That sounds totally weird, that metering has any influence on focussing! You must be doing something else differently.

EdMichaels
09-09-2006, 05:24 PM
well i picked up the lens yesterday after work... got off about 30 pics of various aperatures... i will take some tonite after work and post findings, but first thoughts are im not too impressed at f2.8 when viewed on the LCD..

1. i like the feel of the knurled lens and the weight
2. focus seemed snappy and not loud like others report
i took some pics of my driver licence at ISO 1000 f2.8 ss1/250 and my name looks like a shot with the 70-200 without VR, i kept the settings the same and shot 4/5.6/ 7.1 and f9, to be honest it didnt appear to get real sharp until f7.1, which im not too happy about..

i am gunna search fo a focus chart i think ive read about and print it off and do some comparos for you all...

stay tuned...

any tips to test sharpness..like if i print the focus test chart for the D70 can i shoot hand held str8 on to guage sharpness...im not looking for backfocusing??? nor do i currently own a tripod....
thanks

I owned serial number 000794. made the mistake of thinking it would be a lightweight, pocketable companion lens when I was carrying and using old dependable 70-210/4.5.6 AFD on a D200 ...WRONG! The lens has gone back to www.nycv.com as did the 18-200 VRII AFS Nikkor.

I can not tolerate sub-standard contsruction in a lens whether it is $450.00 or $750.00. Both lenses are "plastic toys", not suitable for humid or hot environs let alone an occasional bang into a hard object.

In the case of the Tamron, focus issues are a problem on every D200 I own or have tried as well as with everyone my dealer has sold. The lens will many times stay at infinity once in focus at a distant point and require power down of the camera or switch to MF to move the focus ring. Although it is optically superior to the Sigma 18-50/2.8 and shares focus issues, the slower focsing, non-Nikon direction for focus and zoom, Sigma is better built, communicates and mechanically functions well with the D200.

It looks like my lightweight lens kit, which all fits in vest pockets and eleminates the need for a bag, remains my Sigma 18-125DC 3.5-4.5, Nikon 70-210/4-5.6AFD, 105/2.8VRII AFS Macro which can double as a medium 160mm f/2.8 tlel amd if anticipated low light my 50/1.4AFD which becomes my short 75mm, fast tele. Obviously one lens is always on a body so the vest load is minimal.

Full lens kit still includes 12-24/4. Tokina, 17-5/2.8 Nikkor, 70-200/2.8 Nikkor, TC 14E.

Ed