[vincent_photo]

[quote name='nc cat' timestamp='1292702959' post='5092']

i have the same findings with my tamron 70-300 on my d7000. it seems to underexpose by about .5 to 1EV.

i compared the same scene from the same location using both 16-85 and 70-300 both at the 70mm setting.

the tamron would show a faster shutter speed (Av mode) than the 16-85 and would result in underexposure.



what i also noticed was that the camera's metering seems to be more sensitive to the tamron when pointing the camera to a different area of particular scene.



i'm going to try Tv mode.



has anyone talked to tamron about this yet?

[/quote]



I called in: they said they'd fix it free of charge, bringit in on monday.

[Steinar1]

[quote name='woodsfortysix' timestamp='1290904258' post='4505']

I also just ran the same series of tests with my D700 and added the Nikon 28-300 lens. The exposure results for the Tamron were identical with the D700. The 28-300 exposure results were close to the Nikon 70-300VR at 70 and 300.



I know this is not a very scientific test, but it appears that my Tamron is underexposing in aperture mode, but exposes correctly in shutter mode if there is "headroom" to adjust the aperture.



Appears that if I shoot in shutter mode, I will be okay...



Comments / suggestions...



Thanks,

[/quote]



I am delighted to hear/see your findings. They coincide with my own on a D300s. Sharp pictures, but underexposed by .5 at least in Aperture mode. Likewise, I am delighted to hear that it performs well on a D700. I am getting one <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='' /> and wondered how the Tamron would hold up against the D700 sensor. Any more of your experience on the D700 would be appreciated.

Kind regards Vieux Loup

[miro]

My EF mount tamron reports at EXIF data max lens aperture 5,4 at 300mm

I cannot say that I have exposure problems. For exposure the lens behaves similar to my tamron 17-50.

Since i shoot digital I don't take the exposure issues seriously.





greetings,

Miro

[Klaus]

FWIW ... I just got a sample in EOS mount for testing.

[Brightcolours]

[quote name='Klaus' timestamp='1296997786' post='5888']

FWIW ... I just got a sample in EOS mount for testing.

[/quote]

Great... I am expecting it to be sharp for the kind of lens (bit sharper than the Canon 70-300 IS and quite a bit sharper than the Nikon 70-300 VR for the one Markus will test), with a bit high CA, which is easily correctable for this lens.

[sth]

[quote name='Klaus' timestamp='1296997786' post='5888']

FWIW ... I just got a sample in EOS mount for testing.

[/quote]

Cool, I can't await the review(s) of that lens.



Just out of curiosity: Could you post the first three digits of the serial number? <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='' />

[Klaus]

[quote name='sth' timestamp='1297010524' post='5899']

Cool, I can't await the review(s) of that lens.



Just out of curiosity: Could you post the first three digits of the serial number? <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='' />

[/quote]



FWIW, the initial findings are good albeit not outstanding.

[koulang]

Now the lens is reviewed at lenstip.com

From the review, it seems a bit disappointed for its image quality. At 300mm the lens is even worse than Nikon 70-300mm VR. I used to use Nikon before, and I was disappointed with its IQ at 300mm. I will never buy this lens unless the reviewed lens was bad copy.

[Klaus]

[quote name='Koulang' timestamp='1297148343' post='5947']

Now the lens is reviewed at lenstip.com

From the review, it seems a bit disappointed for its image quality. At 300mm the lens is even worse than Nikon 70-300mm VR. I used to use Nikon before, and I was disappointed with its IQ at 300mm. I will never buy this lens unless the reviewed lens was bad copy.

[/quote]





It's similar to the 70-300 IS (non-L). A bit better and worse here and there. No big difference. About the same rating.

[miro]

As usual your test results match closely my experience with the lens.

Behind the very good IQ I’d like to mention few minor drawbacks.



1. The lens is heavy. Attachment of tripod is challenge, even on 50d. This is probably minor issues since the lens targets the group of people that rarely used tripod.

2. The zoom ring and AF ring has different position compare to all my other lenses. I still cannot get to use the zoom ring in my action shoots.

3. The AF is fast but there is no focus limiter

4. VC works fine but there is no dedicated panning mode??? Does the VC switch automatically to panning mode when I move the lens horizontally?



I like this lens. babove drawbacks are minor and I'slowiy get used to live with them.





Thanks ,

Miro



PS The IQ at 300mm by my lens is reasonable good at 5,6. Nothing to worry here. Actualy very good for 400Euro lens