Tamron announces his first ultrasonic AF lens!

[Juza]

Tamron has announced the SP 70-300mm F4-5.6 Di VC USD: http://www.tamron.co.jp/en/news/release_2010/0309.html

The interesting thing about this lens is that is uses an ultrasonic AF motor...it is the first Tamron lens to use this technology By the way, it is "true" ultrasonic motor, with full time manual focus, it is not "micro usm" as the Canon 70-300 IS USM.

[the_cheetah]

YIPPPPPPPPPEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE....there are a few Tamron lenss I would use but dont due to the diesel motor they have been using for AF....at last...

[SteB]

Interesting, and the_cheetah I have to laugh about your diesel motor analogy as its very good, and very apt. Tamron are also claiming that the IQ of this lens will be the best in classs. It will be interesting to see how this bears out. My experience with this type of 70-300mm zoom is that most a quite good up to about 200mm, and then get a lot softer afterwards. The better ones just being less soft than the others, rather than being particularly good. So what will be interesting to me is if this Tamron manages to buck the trend and avoid the sudden drop off in IQ after 200mm that most of these lenses appear to suffer from. It's only a pity that the ultrasonic AF didn't go into the Tamron 60mm f2, which from what I've heard, most definitely has a diesel motor as it sounds like an old taxi in need of a service.

[Nico]

they also claim they have put a XLD glass in it with the same qualities of fluorite. Not so sure about that but I would gladly want to try one time.

[the_cheetah]

I have a 28-75 2.8 and as good as it is, sharp and contrasty, the AF stops working after 3pm due to insufficient light. Lets see how this affects their pricing though.

[babyjax13]

I love my 90mm macro Tammy, nice to see them coming out with more interesting stuff

[mindaugasdd]

Nice lens and more promising. But we must to wait until it be tested. And we will see how good it will be. I already like it's mechanical design

[tomatito]

I have never used manual focus during the autoamtic focusing..I trust the camera focusing senzors ..I think it is absolutely uselessness this fulltime manual focus..

[Vellu]

Nice to see that Tamron finally decided to put a ultrasonic motor in to a lens. I hope to see more lenses from Tamron with USD!

[Nico]

I have never used manual focus during the autoamtic focusing..I trust the camera focusing senzors ..I think it is absolutely uselessness this fulltime manual focus..

yeah actually I never use it too. Only when im taking portraits with a macro lens.

[squishy]

I find full time MF valuable for a lot of macro (my camera doesn't do full time MF, but it has an AF button I can engage while in MF mode, giving the same effect)

I'll let the camera roughly focus on the subject to speed things up, then do the finer adjustments myself.

[overread]

I tend to do all my macro in fulltime manual focus so the USM or lack or does not limit me that way; however its a fantastic feature to be able to use AS and manual focus one after the other quickly and without having to fiddle around to find the AF on/off switch.

Myself I use backbutton AF focusing - so that the AF is activated by a button on the back of the camera body, I hold it down and AF kicks in (ai servo in my case as wildlife is always moving) hold the button down to keep AF going and use the shutter button as normal. However if the subject suddenly holds still for a moment I can release the AF button (after its got a lock) and recompose the shot so that its no longer central (since I tend to only use the middle AF point). I can then take the shot with this non-central composition because the shutter button won't start up the AF (which would start to lock onto the background areas).
USM focusing comes into this because often as you recompose the focus with slightly shift because you are changing the lens to subject angle - so being able to fine adjust the focus quickly and without hunting for that AFswitch on the lens is a fantastic thing. Note that if you are using constant AF modes don't start to try and change the manual focus whilst the AF is working otherwise you are going to be fighting the motors; it might no break them but it certainly won't do them any good

With my macro lenses it also means I can leave the lens in auto focus and do macro work whilst also having the lens ready to do autofocusing on further off subjects in a moment.

USM is also a lot lot quieter than regular focusing motors and also faster as well. So even if you don't take advantage of the fulltime manual focusing you can still delight in faster and quieter AF.

[SteB]

I find full time manual focusing in AF mode pretty hand with my Sigma 150mm macro especially with the 1.4x converter. Basically I use it as a bit of an ad hoc birding lens at times and that is the only time I use AF with it. However, like a lot of macro lenses it can sometimes get a bit lost in AF, even with the focus limiter on, but if you pre-focus with the MF it's pretty snappy - unless it misses the target. Likewise with my Bigma 50-500mm on my Olympus E-510 it's pretty handy because the AF struggles after mid-afternoon, and a bit of MF assistance makes a lot of difference. So I can see it being useful on a slower lens like this that might tend to get used on the lower end DLSRs that don't have such good low light AF, especially with the f5.6 max aperture

[tomatito]

actually..when I was doing macro I was always using just manual focus, when I am doing birds photography I was always using AF and servo on Camera so I trust the lens and camera, when I am doing portraits I am using AF and I neved had any problem with it..the only problem I always had was when I had some manual lenses and 70 percent of my photos were out of focus :D so for me the full time manual focusing (during AF) is useless ..probably I am blind .. (sory for english)

[SteB]

Hi tomatito

I understand you are speaking from experience. I hardly ever use AF with macro and the only time I have tried it is with insects in flight. If you have a good lens and camera I can understand relying on AF. The only time I have had to use manual focus with the AF, is when I have been using cameras or lenses that don't always works so well in AF. Having spent such a long time with manual focus before there was any AF I never quite trust AF and I'm always amazed when it works. Focusing screens in modern DSLRs are not very good for manual focus, especially with wide apertures.