NormanTheGr8 Loc: Racine, Wisconsin

I watch A LOT of Lens reviews and I seem to have discovered a pattern Tamron seems to do better in real world shooting on Canon cameras and Sigma on Nikon ,Not better than OEM but a lot closer to the point that I don't really bother with a comparison of say just the Canon vs Sigma . Seems Tamron has Canons algorithm figured out just a touch better and Sigma has Nikon's a touch better . Has anyone else noticed this ?

ltj123 Loc: NW Wisconsin

Don't know really, I've had both on my Cannons, recently sold Tamron 18-250 with 7D2, worked really well for long time. Still have Sigma 17-35 that been using with my 6D2 any quite happy with results so far. Only have had the 6D2 couple months so will see over time...

rook2c4 Loc: Philadelphia, PA USA

Perhaps Tamron and Sigma pay the professional reviewers really well. Or they let the reviewers keep the lenses if the review is favorable.

This is why I simply don't trust most lens reviews. You don't know what is going on behind the curtain - the relationship between reviewer and lens maker. A lens manufacturer would be foolish to continue sending a reviewer sample lenses if that reviewer publishes too many negative reviews. And the reviewer needs the manufacturer to continue sending lenses for review.

dennis2146 Loc: Eastern Idaho

On the other hand if a lens manufacturer continues to receive poor reviews the company might be encouraged to step up the manufacturing quality of the lenses. I am sure at some time with some reviewers this fraud might have happened. But to me your post presents it as an every day occurrence. Who would trust a reviewer if it posted fraudulent information?

Dennis

rmorrison1116 Loc: Near Valley Forge, Pennsylvania

Sorry, pet peeve, it's CANON. As for the OP'S question, no have not noticed this phenomenon at all. My Tamron SP 70-200 f/2.8 works almost as well as my Canon 70-200 f/2.8. The Canon focuses a wee bit faster but it also has a different focus motor and costs substantial more. As far as duplicating Canon's OS; my job is a programmer analyst and I'm fairly familiar with how this stuff works, have been doing it for over 35 years now, and when one is duplicating another's software, there's really no such nothing as almost. The programs are reading input from various input devices and telling other components what to do. It's either right or it doesn't work.
As for Sigma and Canon and Nikon, I have the Sigma 150-600 in both Canon and Nikon and I've not noticed any substantial difference in the way either lens works.

dcampbell52 Loc: Clearwater Fl

I have one Tamron lens (Tamron DX 10-24mm wide zoom). I have used it for 4 or 5 years on my Nikon D7100. It was a gift so I am kind of stuck with it. I like the lens okay but have used the Nikkor DX 10-24mm and it performs a little better. The ONLY real difference is that the Tamron tends to barely fisheye at 10mm. The Nikkor does not. The fisheye is barely visible on the Tamron but it is there and becomes noticeable on images enlarged to 8x10 or larger. I can bump to 12mm and it goes away. Is the Nikkor worth an extra 2-300 dollars because of that? ... I don't know.. it depends on how you use the lens. Personally, now that I have an FX (Nikon D610) and the Nikon DX (Nikon D7000 and D7100), I am gravitating to ALL FX lenses as they work great on both cameras and tend to be better quality lenses. Nikon considers (generally) their DX lenses to be "entry level" lenses and while they make a corresponding FX (the Nikkor 10-24 DX and the Nikkor 14-24 FX). The Nikkor is roughly twice as much as the Tamron was so, I can work with the Tamron, knowing the minor issues. But, it would be nice the have the FX lens for my FX camera since I primarily use it for my wide to "normal" shots.

ltj123 Loc: NW Wisconsin

Yup I know, Canon. Dang it didn't review spelling, I bad. But see your smart enough to figure that out. And I've only got 49 years experience with photography and 36 years programming in several areas, was fun and a paycheck for me.

PixelStan77 Loc: Vermont/Chicago

Agree 150 Percent. Same with Car Reviews In Motor Trend.

NormanTheGr8 Loc: Racine, Wisconsin

I am not suggesting that the aftermarket work better than OEM just the Tamrons tend to edge out the Sigma on Canon , and and the Sigmas tend to edge out the Tamrons on the Nikons . The OEM is 99.9% of the time the best lens in the comparison

mwsilvers Loc: Central New Jersey

I think the OP was referring to the Canon AF algorithms which are proprietary and not publicly available. As a result 3rd party lens manufacturers have had to reverse engineer them. Sigma especially has had a few issues with AF consistency on some of their ART lenses on some Canon bodies as a result.

Most of these problems tend to be most noticable when using fast lenses wide open on lower contrast subjects. Achieving accurate focus in those conditions can be difficult with any lens, but some Sigma lenses tend to struggle a bit more then Canon lenses. This has been my experience as well as the experience of many other people.

Having said that, once you identify if you have AF inconsistencies with your Sigma's AF for your particular lens and camera body, you can mostly compensate for it. You must ensure that you focus on hard edges or areas of greater contrast and perhaps stop down from full wide open a bit in some low contrast or lower light circumstances. In real world shooting I run into this problem much less often then I do if I'm specifically testing for it. These AF problems also occasionally occur even when stopped down, but they are far less frequent and much less obvious unless you pixel peek every shot. Understand that what I'm talking about is inconsistent shot-to-shot AF. As a result, adjustments in the USB dock will not not fully resolve them.

mwsilvers Loc: Central New Jersey

This of course is a generalization and individual experiences can vary greatly. And while I don't believe you specifically mentioned it in your posts, the performance issues are related to autofocus accuracy and consistency and not overall image quality. In fact, until very recently, the newer Sigma lenses produced better image quality on Canon bodies than Tamron lenses. In the last year or two Tamron has begun to up its game. But when it comes to prime lenses, Sigmas are first class regardless of what camera body you are using them on.

NormanTheGr8 Loc: Racine, Wisconsin

Correct

dsmeltz Loc: Philadelphia

I have read a good number of reviews where the Tamron or Sigma do much better than the OEM lenses. Sometimes the OEM just does not have a comparable lens (150-600 come to mind) some times they do (Sigma 50mm 1.4 Art lens)

rgrenaderphoto Loc: Hollywood, CA

Don't care about YouTube reviews, your actual use is what matters. I have Tamron,Sigma and Nikon lenses, and feel in some categories, they are even better than OEM

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

The most important factor here is the knowledge of the operator, not Canon, Nikon, Sigma, or Tamron. IT HAS, AND ALWAYS WILL, COME DOWN TO THE OPERATOR, NOT THE EQUIPMENT. WORRY LESS ABOUT EQUIPMENT AND MORE ABOUT ACQUIRING KNOWLEDGE AND TECHNIQUES TO GET A GOOD SHOT EVERY TIME.