[Clem Nichols]

I realize that many are agonizing right now over whether to purchase the Tamron or the Sigma 70-200 f/2.8 lens, and in fact I am one of them. The other choice in my book, however, is the Pentax 50-135 which continues to receive accolades from just about everyone who has one. I had originally been holding out for the upcoming 60-250, but if the price tag is roughly twice that of the above mentioned lenses, then that lens is no longer on my short list. I anticipate using whichever lens I decide on taking pictures of my grandkids playing high school basketball. Apparently none of the above three is particularly fast focusing, at least on the K10, so the deciding factor boils down to image quality. I guess what I'm wondering about is whether or not a cropped 135mm image made with the Pentax would be equal in quality to a 200mm image made with the Tamron or Sigma. The Pentax would certainly be more user friendly because of the weight difference, but I wouldn't want to give up too much in IQ. Anyone have any ideas?

CN

[kenyee]

pictures of my grandkids playing high school basketball

Get the long lens unless you get to sit on the sidelines...

[Lowell Goudge]

This is a question of what range of lenses in total you want in your bag.

my own opinion is that if you practice a wide variety of photography, from archatecture to landscape to portraits to wild life you need ultimately to cover from about 10/12mm at the wide end towards 400mm at the long end.

the question then becomes how do you want to fill this range.

For general shooting I do it with 4 lenses (Known as Lowell's Lens List or LLA)

Sigma 10-20mm
Pentax 18-35mm FA-J
Tamron 28-75mm F2.8
Sigma 70-200 F2.8 plus 1.4x and 2x TCs

this gives the range in noted above.

If you don't need wildlife and speccifically long telephoto, perhaps the 50-135 is OK for you. This could change your package to be either the sigma 10-20 or pentax 12-24, then a 16-50 F2.8 then the 50-135 (or sigma 50-150) as a 3 lens kit.

You could also decide that there is not much use between 135 and either 300 or 400 and simply get a long prime as opposed to a zoom or teleconverters.

If you are thinking between the 70-200 or 50-135 it is time to map out your entire system

[Denis]

II anticipate using whichever lens I decide on taking pictures of my grandkids playing high school basketball. Apparently none of the above three is particularly fast focusing, at least on the K10, so the deciding factor boils down to image quality.
CN

I have the Sigma 70-200 EX DG II HSM. As for focusing, it is as fast and quiet as any others. Problem is the same for many other brands, enough light and contrast to focus on. I have taken a few photos of my son playing volleyball. It works well even at 2.8 and as high as 1600 iso. He starts his basketball season in mid-October. I will test it then to see if it is suitable.

With time, I have impoved my ability to take basketball photos. I have found that if you stay low and shoot toward a light color wall, you can increase speed and decrease iso to improve IQ but most of all a fast f2.8 lens is minimum requirement.

[bigben91682]

I was thinking about buying the 70-200 as well, I'd love to have the range at weddings. I already have the 50-135 and I love it. The problem is that if I do get a 70-200 I think I'm going to have a hard time parting with 50-135....

The 60-250 looks nice but I can't justify that kind of money for a lens at f/4, no matter how versitile it is....although the price will surely come down eventually. Maybe I'll bite at the $1000 mark.

[24X36NOW]

Buy yourself a used Pentax 70-210 F4 "A," which will probably beat both the Tamron and the Sigma on image quality, will cost you less than $200, and uses a one-touch zoom/focus ring that will enable you to compose, focus and shoot quickly without worrying about how well the autofocus system works (or doesn't) in indoor lighting. Extra 10mm reach too.

[Clem Nichols]

This is a question of what range of lenses in total you want in your bag.
If you are thinking between the 70-200 or 50-135 it is time to map out your entire system

Lowell:

Good advice. Actually I'm pretty well covered range-wise with the Sigma 10-20, 17-70, 70-300, and 50-500. Speed-wise, however my only two fast lenses are the Pentax 50 f/1.4 and the Sigma 30mm f/1.4, neither of which is nearly long enough for my intended purpose. I gather that the Pentax 50-135 is sharp wide open at all ranges. Likewise I've heard that the Sigma is fairly soft wide open above 150mm and that the Tamron's auto-focus leaves something to be desired although it supposedly has great image quality. For obvious reasons my basketball shots will probably all be at f/2.8, and that's what led to the question in my original post. Do you think it's likely that a cropped image made with the Pentax 50-135 will be as good or better than the same size image made with the Sigma 70-200. Between the Sigma and the Tamron I'm leaning toward the Sigma despite what I've read in some of the reviews.


Denis:

Have you formed an opinion yet regarding the IQ of your Sigma when shooting wide open at 200mm? Thanks for your response.

CN