Tamron 28-75

Hi, I have read a few reviews for the Tamron 28-75 f/2.8 lens and I am a little confused if there are two types of this same lens.

On fredmiranda, I see

1. Tamron AF 28-75 f2.8 XR Di Zoom and
2. Tamron SP AF 28-75 f2.8 XR Di LD Aspherical (IF)

Are they different and if yes, can someone explain the difference.

annother one on my wish list....Like to know about this!!!

Hmmmm........

I just ordered the Tamron AF 28-75mm f/2.8 XR Di LD Aspherical (IF) from B&H. That's the only one I have seen at every dealer. Maybe they are both the same? The one I ordered is also the only one on Tamron's site....

But why on earth would there be two seperate review sections for it?

GRRRRR!!!!!!!! If they are different for some reason....I do hope I ordered the better one!

i was under the impression that the 28-75 just came out with the (IF) at this point is where it became a hit. the older one isn't an IF i believe and has been out for awhile.

What's the difference between a lens with internal focusing and a lens without it?

Internal focus? Can someone please give me a link to a lens with external focus? I've never heard the term IF before, sounds like marketing speak.

From what i've read here and on fredmiranda.com I don't think there's a significant new version of this lens.

Jackal, my concern exactly. The 'Aspherical' has a lower rating than the 'Zoom' version. If they are indeed different, the ones available widely now seems the lower rated one

If the basic choice of lens is not confusing enough, this is one additional layer I guess!!

I'm pretty sure there is only one version of this lens, proudly bearing all these acronyms. The different versions at FM reviews are probably old and new versions of the reviews rather than old and new versions of the lens.

I think jyrgen is correct. When I was researching this lens I asked myself the same question and concluded that someone had just added the second lens without realising it is the same as the first. I didn't find two versions of this lens.

You can add reviews on FM and a few other lenses on there have the same multi entry problem. I just added the scores together to get an overall AWESOME LENS score

On the box that mine came in it says Tamron SP AF 28-75 f2.8 XR Di LD Aspherical IF and I bought it new about 3 weeks ago.

The other lens I considered is the new Sigma 24-70mm f2.8 EX DG Macro.

On the IF issue ... my 100-300mm Sigma has an internal focus mechanism and here IF means that the barrel doesn't go in an out as you zoom. My Bigma used to extend quite a way on full zoom. I prefer the IF as the lens stays the same length. However, with the Tamron the barrel does go in and out as you zoom ... and so I have no idea what it means for them as there was nothing on their web site to clarify!! But Tim is right ... marketing speak and who cares!

Tim, I think that "internal focus" refers to a focusing system which doesn't extend the lens: the length remains the same from close-up to infinity.

pierrot wrote:
Tim, I think that "internal focus" refers to a focusing system which doesn't extend the lens: the length remains the same from close-up to infinity.

Isn't internal focusing the fact that the front element doesn't turn when focusing?

Well, a forum search with the words 'Tamron Version' brought up this thread that was posted a week ago and should answer the questions posed and discussed here.

In a nutshell ... there's only one lens.

Hope that helps.

Best regards,
Andy

I've never heard of a lens that extends to focus, only lenses that extend when they zoom. I still think it's marketing bulls***.

FYI - One example, a lens that you probably have or had, is the Canon 50mm F/1.8 which has a linear extension focusing system. It extends out or retracts back when changing focus. All that said, it's not marketing BS afterall.

Interesting, thanks for the tip. Can anyone explain why it's a bad thing, or why Tamron are pushing the IF system? I really don't care if the back of my lens moves.