[krishna]

Does the SR function in Pentax K-x work with Tamron 70-300mm f/4-5.6 Di LD Macro Lens?

Do we need to manually input focal length in K-x for this lens? I could not find much information on this in the user manual.

Is there any compatibility issues observed in K-x with the above mentioned lens?

[RioRico]

1) You will have no SR problems. Any lens put on a modern Pentax dSLR gets SR if you want it.

2) According to online literature, this is a modern AF lens and you won't need to input any SR data. Some people love it, but some warn that it isn't the sharpest, expecially above 200mm.

3) You should have no compatibility problems.

If you hit this gargle you'll find lots of information.

[krishna]

Thank you for your quick reply.

I had been doing a research on the following lens for a long time for my Pentax K-x:

• Pentax SMC DA 55-300mm f/4-5.8 ED
• Tamron AF 70-300mm f/4.0-5.6 Di LD Macro Zoom Lens
• Tamron AF 75-300mm f/4.0-5.6 LD

Just for my information, how about compatibility with older Tamron AF 75-300mm f/4.0-5.6 LD lens?

Most reviews states Pentax 55-300 having an edge over Tamron 70-300.

[Pentaxie]

Of course the 55-300 has an advantage over the 2 Tammies since it is a Pentax lens.

For me I would choose the Pentax lens as it has more reach (50-300mm as compared with 70-300mm)

[flippedgazelle]

Thank you for your quick reply.

I had been doing a research on the following lens for a long time for my Pentax K-x:

• Pentax SMC DA 55-300mm f/4-5.8 ED
• Tamron AF 70-300mm f/4.0-5.6 Di LD Macro Zoom Lens
• Tamron AF 75-300mm f/4.0-5.6 LD

Just for my information, how about compatibility with older Tamron AF 75-300mm f/4.0-5.6 LD lens?

Most reviews states Pentax 55-300 having an edge over Tamron 70-300.

Any AF lens will have automatic compatibility with Pentax's SR.

As for comparing the Tamron 70-300 with the Pentax 55-300, here's from my review comparing the 2:

This came as part of the K-x 2 lens kit, which cost $180 more than the standard K-x/18-55 kit.

One of the major complaints of the "L" version of this lens is the fact that it does not include a hood. Given the price of the lens (when included in the kit) I understand the lack of a hood. My big complaint about this is the lack of availability of a hood at a reasonable price. If a Pentax lens hood were readily available for $29.95, that would be fair IMHO.

For me, this lens replaces a Tamron 70-300 LD Di, with which I had good success. I'll use the Tamron as a basis for comparison.

Where Pentax wins: wide open @ 300mm, the 55-300 is clearly sharper. The contrast and (especially) color are worlds better. The Pentax has less, though still evident, CA. The Pentax has better bokeh IMO. 55mm is sometimes useful.

Where the Tamron wins: price (currently ~ $160 w/lens hood). Build quality is a bit better. Stopped down at 70mm, the Tamron is a bit sharper. Biggie for me - the Tamron has a 1:2 "macro" mode that is very useful compared with the Pentax's 1:3.6 (or whatever). The Tamron has a min. focus distance of 39", so if there is something at my feet I can quickly and easily get a shot, whereas with the Pentax the min. focus distance is 55", which makes that sort of close-up shot much more difficult. Tamron has an aperture ring, useful with MF teleconverter.

Both lenses are slow-focusers.

In a weird kind of way, the comparison between the Pentax and Tamron lenses boils down to this: the Pentax is better optically, the Tamron has more features.

In large part due to the lack of a lens hood, and the fact that on the rare occasions the lens hood is available it's $50-60, I'm rating this lens an "8".

[flippedgazelle]

Of course the 55-300 has an advantage over the 2 Tammies since it is a Pentax lens.

For me I would choose the Pentax lens as it has more reach (50-300mm as compared with 70-300mm)

There is no inherent advantage for the Pentax lens over the Tamron lens due to one being "Pentax". The camera does not communicate differently with the lens.

[jct us101]

I think you'll notice that the SR is a little less effective at longer focal lengths (although this is a problem with any brand) because of 300mm being so vunerable to any kind of vibration or shake in the camera.

[epqwerty]

Yes the Shake reduction will work with the Tamron lens. Actually thats one of the benefits of the Pentax SR system. All lens you use will be SR enabled.

No you do not need to input focal length due to the lens capable of transmitting it's focal length to the camera body.

The only advantage that the pentax has over the tamron is the image quality is better than the tamron. But don't forget the Tamron has macro 1:2 capabilities that the pentax does not. I'm not saying 1:2 is awesome but it's better than nothing.

[JeffJS]

Thank you for your quick reply.

I had been doing a research on the following lens for a long time for my Pentax K-x:

• Pentax SMC DA 55-300mm f/4-5.8 ED
• Tamron AF 70-300mm f/4.0-5.6 Di LD Macro Zoom Lens
• Tamron AF 75-300mm f/4.0-5.6 LD

Just for my information, how about compatibility with older Tamron AF 75-300mm f/4.0-5.6 LD lens?

Most reviews states Pentax 55-300 having an edge over Tamron 70-300.

If you're going to buy a Tamron, get the Di version. I cannot say that it's better or worse than the Pentax because I've never owned the 55-300 (and probably won't). THESE are taken with my copy on the K7.. The file title gives indication of the focal length and there are a couple macro test shots as well. THESE were taken with the same lens (except the squirrel shot) on the K10d. Exifs should be in tact.

SR works fine with the lens. You only need to worry about Inputting a focal length with a Manual lens (M42, K, M, A type manual focus lenses).

Good luck..

[Pentaxie]

Yes, SR works fine with the lens. Bur on a longer value, > 200mm it may pose a problem due to the length. SR is not so effective at a higher length.

For Manual lens (M42, K, M, A type manual focus lenses etc), you will need to input the data on the focal length. For all autofocus lens, no need to concern about it.

[Pentaxie]

There is no inherent advantage for the Pentax lens over the Tamron lens due to one being "Pentax". The camera does not communicate differently with the lens.

I agree, unless one compares between Pentax SMC DA 55-300mm f/4-5.8 ED
with Tamron AF 75-300mm f/4.0-5.6 LD where the Pentax lens is suited(made for) for digital APS-C camera as compared with the Tammy (which I believe is used previously for FF film SLR - please correct me if I am wrong).

Both the Pentax & the Tammy Di lens are made for digital camera.

[jct us101]

I agree, unless one compares between Pentax SMC DA 55-300mm f/4-5.8 ED
with Tamron AF 75-300mm f/4.0-5.6 LD where the Pentax lens is suited(made for) for digital APS-C camera as compared with the Tammy (which I believe is used previously for FF film SLR - please correct me if I am wrong).

Both the Pentax & the Tammy Di lens are made for digital camera.

Oh there's a difference at least in the quality of those lenses. One might equate it to the SR, but in reality the Pentax is just a better lens. The brand has no bearing on what the SR does.

[Ahab]

Yes the Shake reduction will work with the Tamron lens. Actually thats one of the benefits of the Pentax SR system. All lens you use will be SR enabled.

No you do not need to input focal length due to the lens capable of transmitting it's focal length to the camera body.

The only advantage that the pentax has over the tamron is the image quality is better than the tamron. But don't forget the Tamron has macro 1:2 capabilities that the pentax does not. I'm not saying 1:2 is awesome but it's better than nothing.

Quite true, but I have no problem with the the Di Tammy's image qualiy.

[Marc Sabatella]

don't forget the Tamron has macro 1:2 capabilities that the pentax does not. I'm not saying 1:2 is awesome but it's better than nothing.

While that is true, a $40 Raynox 150 in front of the 55-300 turn it into a far better macro lens than the 70-300. No way would I choose the 70-300 over the 55-300 on this basis.

[TER-OR]

I have the Tammy 70-300, and have taken a lot of very good shots with it. At the long end, it has chromatic aberration issues - purple fringing. I bought mine used, and inexpensive. I'm sure eventually I'll move to the Pentax zoom and sell the Tammy to someone else, cheap. Until then, I'll make do taking shots around 180mm before zooming to 300.

I have found the Tammy lens to focus well (I don't know how fast it is without comparison). It's also quite light, which is nice on the shoulder strap.

BTW, I'm shooting with a K-10D