[Dma110]

I am trying to decide on a UWA. I'm torn between the sigma
10-20 f4 and the tamron 10-24. I've read good & bad about
both, and seen excellent photos from each. I lean toward the
tamron because 1. I like the longer reach 2. 6 year warranty
3. Have a tamron 28-300 now & love it.
Now comes the stupid part. The tamron's lens hood is just
too big to fit in my camera case (a small lowepro omni traveler)
without removing my flash. From what I've heard the sigma hood
is reversible and would fit w/o removing anything. I know I am a
drooling idiot to pick a lens just because it fits in a bag.
I guess what I'm asking is the tamron so good it would be worth
carrying my flash separately , or is the sigma so good I won't
miss the extra 4mm. I have overlap either way since I also have
the 18-135.
Would appericate any comments. Sorry for the long, rambling post

[hray]

Does your Lowepro Omni Traveler have attachment points for the Lowepro lens cases? I've got the Tamron 10-24 and really like it; it does fit in my Lowepro Slingshot 102 but I also bought it a Lowepro Lens Case 1W--the Tamron fits in it beautifully with the hood on, and the attachment to the outside of the Slingshot is very secure. FWIW!

lowepro lens case 1w

[DSims]

I skipped both and got the DA15. It has better IQ, fabulous colors, and you just stick it in your pocket. Then you still have room for another small lens in your bag.

Alternately the DA10-17 has fairly low geometric distortion at 17mm, but is equivalent to somewhere around (I believe) 12-13mm rectilinear at that end. Colors are close to the DA15 and it's both versatile and fun. I have one and it sounds like it would fit in your bag.

[Coeurdechene]

The tamron's lens hood is just
too big to fit in my camera case

you can remove it, store it appart or find a way to place it...from the reviews the tammy's got some problems of sharpness and contrast wide open, but stopped down it's great...Dpreview gives it the edge..and the price is similar.
The 10-20 3.5 is also there, a bit more pricey but sharper (well, it also has worse chromatic aberration issues, and more barrel distorsion at 10mm).
but if the hood was what was bothering you...just remove it when you'll pack the lens!
Good luck (and don't think of the 8-16).
(i'm in, kindof, the same dilemma but add to the mix trying to decide if the UWA, a strobist setup, the 8mm 3,5 or save for the 10-17 or 70-200
f2,8...Gear and limited money hell!)

[AdamP]

I ,too, was debating which one to get. To my untrained eye, I liked the look of photos taken with the Tamron I've seen online better, but the Sigma seems to be the more popular choice.

After finding an open box copy of the Tamron for $350 on Amazon Warehouse Deals, the debate was over for me. I just got it and it seems brand new. The lens hood is low profile and easy to stow when you take it off the lens. If it doesn't fit in your bag, you might be able to attach it to the bag or yourself with a climbing clip.

[Coeurdechene]

but the Sigma seems to be the more popular choice

That's due to the fact that it was released before the Tammy...in fact Tamron got quite "late" to the UWA.

[RioRico]

I mulled mightily over the choice. Kicker was the US$100 discount coupon. So now I have the Tammy. Sorry, coupon expired in January. You're too late. Should have asked in December.

Yes, its hood is large, even reversed. Fortunately, my Ameribag is larger. So the Tammy rides along with the DA10-17. VERY different lenses. And the Zenitar 16/2.8 stays home more.

I'm still deciding how much I like this Tammy. I think one corner is slightly soft at 10/3.5. I need more testing, and test conditions have been lousy lately. Fortunately, there's no rush.

Yes, the Sigmas are more popular. So are McBurgers and crack. (EAT SH!T! 10 TRILLION FLIES CAN'T BE WRONG!) I decide on price/performance, not popularity. And I like the extra 4mm.

[Jewelltrail]

I have bought & love the following Tamron lenses:

Tamron SP 17-50 2.8
Tamron SP 28-75 2.8
Tamron SP 24-135 3.5-5.6
Tamron 23a 60-300 3.8-5.4
Tamron 90mm 2.8 Macro Di

HOWEVER, for my UWA lens I chose the Sigma 10-20 4-5.6. Read the Photozone reviews for the 2 lenses: you will see it is no contest. Final verdict for the Sigma is 5 Stars--for the Tamron 10-24, 3 1/2 stars. Sigma is superior optically & mechanically.

BTW, this is Tamron's 2nd less-than-successful attempt @ UWA--their 1st one was the not-so-well-received 11-18mm. One issue with the Tamron is barrell distortion is throughout the range, whereas the Sigma has it in the borders, @ 10mm, but gets excellent with distortion as you zoom out. But you can read all this for yourself.

Coeurdechene: Dpreview gives it the edge..and the price is similar.

I looked @ the DPReview, but did not see it giving any edge to the Tamron lens. To what edge are you referring? Can you cite it? I would like to read this--thanks.

Coeurdechene: That's due to the fact that it was released before the Tammy...in fact Tamron got quite "late" to the UWA.

Well, it was late getting to the game with something that could compete, even remotely. The 11-18mm flopped, but I'm not so sure the 10-24 is much better, even though it is attractively priced. The Tamron is not a bad lens, and surely worth shooting with, but I do not think it is the best option. Here is a little discussion from Photozone's "Verdict" on the Tamron:

"However, on the other hand the center resolution is very high and stopped down the border and even corner resolution reaches levels, which are probably sufficient for most use cases.

Given its rather low price (compared to similar lenses) it may well be the first choice, especially for those who shoot in this focal range occasionally only. You get what you pay for here: not outstanding, but maybe good enough."

[Coeurdechene]

Studio Tests


"The 10-24mm gives generally good, if not outstanding results; distortion is well controlled and central sharpness is high once stopped down F5.6, especially at 10mm. However sharpness wide open is distinctly low"
In the Tammy review.
And now the edge part, that they give with a grain of salt, it is in the Sigma's review:
"Compared to the Tamron SP AF 10-24mm F3.5-4.5 Di-II, the Sigma is perhaps starting to show its age; the Tamron is significantly sharper across most of the frame at wideangle, although it has serious problems wide open, and the extreme corners tend to be rather soft. Towards the long end, though, the Sigma edges ahead; but it's probably fair to say that wideangle zooms aren't particularly bought to be used in this range, which is shared with the typical kit zoom. The Sigma also shows notable control of lateral chromatic aberration, but against that the Tamron has significantly lower distortion and falloff. This makes the choice between the two less than entirely clear-cut, however the Tamron probably edges it overall, unless you intend to shoot a lot wide open, or really need the Sigma's HSM focusing."

Then they complicate even more the things saying:
" it simply can't match the biting central sharpness of the Tamron 10-24mm F3.5-4.5 Di-II in the 10-18mm range (for which, we suspect, users will mainly be buying this type of lens), and has more problematic distortion characteristics. However in a typical case of swings and roundabouts, the Sigma shows superior sharpness when shot wide open, and is better in the corners of the frame at all settings; it also has lower chromatic aberration, is better built and uses a superior focusing system"
The thing with the UWA's is that none is a clear victor..all of them have trade-ins (the only one who stands out completely is the Sigma 8-16 and that's just because there is no other option with 8mm! reviews are fine but acknowledge a fair lot of problems, common to this kind of angle of view).

And they are both recomended by dpreview (the sigma and the tammy...).
And it's hell and back to chose between the two.

[Dma110]

Thus my quandry. Both dpreview & Photozone give a slight
edge to the sigma, although dpreview rates image quality the
same for both. It seems to boil down to center sharpness on the
tammy vs overall sharpness of the sigma. My heart is saying
the tammy for the zoom range ,but my brain is leaning toward
the sigma for the overall sharpness & the compactness.
This decision is a quandary & a pickle I tell you

[hray]

There is currently, through the end of April, a $50 discount on the Tamron. I just got my check a week ago.

[Dma110]

I know. That's one reason am wanting to buy now. That and
get it in case price & availability problems happen due to
earthquake in Japan. Will be a expensive month for me. A K-5
body, bower battery grip, 18-135 lens, and this. Plus a surprise
mystery camera I'll post pictures of when it comes in

[Coeurdechene]

surprise
mystery camera

Exiting!
It will be an expensive but delightfull week i'm sure

[qtopplings]

I went through the same thought process. I originally bought the Tamron, based on the reviews I read, and mainly because of the price (the $100 rebate). The first copy of the Tammy 10-24 was awful, soft in the corners even through f8. I returned it, and asked for a new copy. I also bought the Sigma 10-20 to compare. The second Tamron was even worse than the first one. The Sigma, however, was flawless. MUCH MUCH sharper, great in the corners, and better made. Hood is much smaller too. In my mind, there is absolutely no contest between these two UWA's. The Sigma wins, hands down.

Check out the Sigma Club: https://www.pentaxforums.com/forums/lens-clubs/84539-sigma-10-20mm-club.html

Here's my shootout of the two: https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/127946-sigma-1...ml#post1326473

And finally the Tammy club (note how many pictures are cropped): https://www.pentaxforums.com/forums/lens-clubs/103557-tamron-10-24mm-club.html

Good luck in your choice!

[Jewelltrail]

DMA110: Thus my quandry. Both dpreview & Photozone give a slight
edge to the sigma,

DMA110, no, you are incorrect---Photozone in no way "gives a slight edge to the Sigma"; rather, they give a great edge to the Sigma--there is no contest between the 2 lenses if you read the Photozone reviews. Here are links to the 10-24 Tammy & the Sigma 10-20 f4-5.6--both on Nikon mount, it is best to compare lenses within mounts. You can also read the 3rd link I provide below, which is for the Sigma on Pentax mount--the Tamron has not been tested on Pentax mount yet.

Tamron AF 10-24mm F/3.5-4.5 SP Di II LD Aspherical IF - Review / Test Report - Sample Shots & Verdict

Sigma AF 10-20mm f/4-5.6 EX DC HSM - Review / Lab Test Report - Analysis

Sigma AF 10-20mm f/4-5.6 EX DC (Pentax K) - Review / Test Report - Sample Images & Verdict

Read the reviews carefully, within mounts, your decision will be easy--also, compare shots with each lens & again your decision is easy. Finally, check out the excellent MTF scores across the range in the Pentax mount, as well as the excellent CA control.