BB Pics from Jan 5

[Hards80]

i was not impressed with the tamron to be quite honest.. the optical quality was pretty good, but not noticeably better than others in the range i have looked at.. and i was really not a fan of the build quality.. to light and plasticy.. i much preferred the feel of the sigma EX's..

you can make an argument that the optics of the Tamron are slightly better than the sigma 28-70 and even 24-70.. but i think if you look at the copy to copy variability, there will be significant overlap.. so is it a significant difference, that i couldn't tell you..

the 24-60 is definately a good sigma lens, probably their most consistantly sharp one in the 24-xx 2.8s..

[davidreeves]

all of this goes too show how subjective photography really is and how difficult it is for a relative newbie to make buying decisions.

I wish our local camera store would allow me to rent both for an afternoon and draw my conclusions looking at images I shoot in my venue

If only life was so simple!

Thanks for your comments. I ammost probably going to buy the Sigma because the extra 80 bucks for the Tamronfor my budget is a real consideration.

[[email protected]]

I work sometimes right across from the Green Monster!

Often I look out the window during meetings and see the lights and the green stands!

I have the Tamron 17-35 and the 28-75 and haven't been too worried about the build quality.

I've seen some really nice sports shots off the Sigma F2.8 zooms.

I probably have a following of about 100 people lookingfor my sports shots in the local paper each week (its a weekly).

So, to give them a different angle, I will shoot one week with a 50mm. The next week I will use the 17-35 and shoot "in tight" to get facial expressions, etc.

This week, for instance, I will be using a 70-200 to get that background out of focus bokeh effect.

Each week I try different shots, different angles, different lenses, different effects.

That way, my100 customers never get bored.

Grant you, I wish I had about 5,000 customers. lol.

Terry

[Africa]

For those who are interested here are the MTF numbers for an 8x10 print, with the lenses wide open (f2.8), at three different focal lengths (higher numbers are better):

Sigma @ 28mm = 95.3, A+
Tamron @ 28mm = 95.9, A+

Sigma @ 50mm = 93.7, A
Tamron @ 50mm = 97.0, A+

Sigma @ 70mm = 93.1, A
Tamron @ 75mm =97.6, A+

At 28mm the Sigma and Tamron are virtually the same but there is, what I would call, a pronounced difference at the two longer focal lengths.

When one looks at letter grade results for an 11x14 print, a higher standard, at all f-stops (f2.8-f32) here's what you'll see translated into letter grades.

@ 28mm the Sigma gets no A pluses, 5 As, 2 B pluses & 1 B.
@ 28mm the Tamron gets 4 A pluses & 4 A's.

@ 50mm the Sigma gets no A pluses, 5 A's, 2 B pluses & 1 B.
@ 50mm the Tamron gets 6 A pluses & 2 A's.

@ 70mm the Sigma gets no A pluses, 3 A's, 4 B pluses & 1 C.
@ 75mm the Tamron gets 7 A pluses & 1 A.

You said "the (Tamron) optical quality was pretty good", well I thought I should give other people a look at some of the numbers. While I would call the results from the Sigma very good the Tamron is clearly outstanding, not "pretty good".

You went on to say "but not noticeably better than others in the range...", I would say the difference is significant. As a matter of fact if one looks at the numbers of the Canon 24-70mm L series lens, the Tamron is sharper!

Then there are those distortion numbers:

Sigma at 28mm "noticeable" pincushion 1.5%
Tamrom at 28mm "slight" barrel 0.6%

Sigma at 50mm "noticeable" pincushion 2.0%
Tamrom at 50mm "slight" pincushion 0.86%

Sigma at 70mm "considerable" pincushion 2.47%
Tamrom at 75mm "noticeable" pincushion 1.28%

As I previously stated, Tamron has less than half the distortion figures as the Sigma. Take either lens, photograph a brick wall, and I'll bet anyone would see the difference.

Now how does one argue with "i think if you look at the copy to copy variability, there will be significant overlap... so is it a significant difference, that i couldn't tell you..."? I couldn't tell either and since you counter your own arguement I can't figure out why you bring it up.

I think we could agree that since both Tamron and Sigma have outlasted numerous independent lens manufacturers over the past 55 years that "copy to copy" variability is not a big problem.

Normally one would have to pay a $55 premium to get the Tamron but they currently have a $30 rebate making the difference just $25 (all prices via B&H). When I made my decision the $55 difference was in place and I found the superior tests results worth the difference.

But I can understand how someone would not find the extra costs worth it, and that's OK. I don't think if someone showed me 4x6 prints, newspaper reprints or 90 dpi computer images from both that I could tell the difference.

I post this diatribe so others can have, as much as posible, a objective view of these two lenses with my commentary as an additive.

Africa

In case it makes any difference I own the Tamron 17-35mm f2.8-4.0 (a disapointment), the Tamron 28-75 mm f2.8 (sweeeeeet) and the Sigma 70-200mm f2.8 (excellent).

At work I have recently been issued all Canon L series lenses: 16-35mm f2.8 (beautiful), 24-70mm f2.8 and the 80-200mm f2.8 along with a Canon 20D. I told my boss I wanted now is a Segway human transporter to get around campus.

[[email protected]]

Now I know why I like Tamron!

I have the 17-35 and I quite like it. Not sure why it's a disappointment for you Africa.

The dirty little secret is the 3rd party lenses manufactueres have to work harder, builddecent quality, and charge a lower price to compete with the name brand lenses.

Not too say that the high end "L" lenses don't earn their keep. But we'd all like to be drinking the highest quality French Bordeaux, but most of us end up settling for a decent priced Californian Cabernet Sauvignon.

So, for those who earn their living by the lens, the high end is definitley justifiable.

But for the cash strapped amateur and semi-pro, these 3rd party lenses are a god send!

Now if I could just afford one of those expensive French reds on a regular basis!

-- Terry

[davidreeves]

ok, I cant resist this ...

I'm on a Boones Farm budget

[sbranch]

I see that you like the Tamron lenses. I am concerned about the claims which abound on the net about getting bad lenses and having to take them back and exchange them until you get a good one. Is this the actual case? Sounds like a headache to me.

I think the Tamron 28-75 sounds like a good option, but am worried by the "experts" claims as set forth above. What is the truth?

[[email protected]]

I own three Tamrons and have never had a problem with any of them.

If you buy from a reputable online retailer like B&H photo video, in the case you get abad lens copy, I'm sure they'd exchange it no problem.



-- Terry