Sony 100-400mm f/4.5 - 5.6 GM OSS knocks it out of the park

[AlanF]

a, I use the 5DSR and 100-400mm II very frequently as it is a favourite of mine.
b, I don't take TDPs IQ charts very seriously as they are done on one copy of a lens only and sometimes under different distances and conditions.
c, It's not good to compare different cameras to compare lenses as different sensors are used.

On b., the copy variation is a valid concern but it's certainly not unique to TDP. DxO, Lenstip, Photozone, ePhotozine, and IR generally all test based on a single copy. LenRentals is the only one out there that consistently tests with multiple copies and then shares the averaged results. TDP also does multiple copies but it's not consistent.

I'm not sure what you mean by different distances and conditions though. The distance he uses is a function of the focal length but the conditions are fairly well controlled.

Yes, indeed, TDP, DxO, Lenstip, Photozone, ePhotozine, and IR as well cameralabs, amateurphotographer, photoblog, pcmag, dustin, tony etc etc etc all test just one copy. That is why you should read all the reviews and look for a consensus, and not just take one result and draw conclusions from that alone. Then, when you decide to buy, you test the copy on sale to make sure it is a good one.

The only site that does rigorous testing is lensrentals. There are several comments on CR about how their findings with lenses differ from TDP. My set of EF-M lenses on the (11-22, 15-45, 18-55, 22mm) doesn't tally well with TDPs, for example.

 

[AlanF]

ps, here is an example from TDP and another lens, the EF-M 18-150mm. I had discounted the lens because it is so absolutely awful on TDP at 50mm and above: see https://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=1134&Camera=812&Sample=0&FLI=1&API=1&LensComp=1114&CameraComp=812&SampleComp=0&FLIComp=3&APIComp=0

But, other reviews have quite good results

http://www.photographyblog.com/reviews/canon_efm_18_150mm_f_35_63_is_stm_review/conclusion/

https://www.digitalkamera.de/Zubeh%C3%B6r-Test/Testbericht_Canon_EF-M_18-150_mm_3_5-6_3_IS_STM/10403.aspx

So, I might just have to order one and try it for myself.

 

[mjg79]

It looks like Sony made an excellent lens. I have tried Sony's mirrorless options and they just didn't gel with me, it's hard to undo years and years of getting used to Canon. Nonetheless I am always pleased when the competition brings out a new product. While Canon are not the type to panic and respond quickly, over the long term they will be of course keeping an eye on the quality of other competitive products. I can't see a 100-400L III for many years but some other lenses in the area - the 3004 and 400/5.6 need updating and it might push them, along with Nikon's excellent 300PF to bring out a 300/4 DO.

I am curious that the Sony is so much lighter than the Canon despite being around the same size. The Canon 100-400L II has a reputation as one of the best built lenses you can buy so it will be fascinating to see what happens when there has been a tear down of the Sony to compare.