The magic of the EF 75-300mm

I will end this debate with the following observations:

1. The 75-300 has almost non-existent vignetting compared to the STM.

2. The 75-300's out of focus area (bokeh) is much more pleasing to my eyes.

3. Sounds weird, but the pictures seem to have better dynamic range with the 75-300 (or it's just a better optimized lens for my T5? doesn't make sense).

4. I find that the closest I can get to match the STM lens overall IQ is by turning down the highlights in ACR.

5. The 75-300 produces much finer noise. I'd call it film grain. After shooting outdoors and using ISO 1600 the images are pleasing. With the STM lens if I'd shoot the same thing with lower ISO (e.g. 400 where you can start to notice some noise), then I'd be fussing. I just realized that the way noise is presented on an image is much more important to me, than the amount of noise. For me the MK iii seems to shine in this area the most, out of all the other points.

6. CA looks worse on the 75-300.

7. Yes, the STM lens is sharper. Although there are 1-2 samples with the mk iii where the opposite is true, but most of the time that isn't the case.

8. The 75-300 has no IS. Zoomed in to 250+ with a shutter speed of 1/500 I had images that were blurry. I'm used to the STM lens and this feels much heavier. I would never buy a tele lens the size of the MK iii without IS!

The magic definetly lies in the vignetting (both produce vignetting, but the MK iii produces a more old-skool, more natural and pleasing one), bokeh and the (lack of) corner sharpness.

I'm giving this old girl back to her new owner, and saving up for the image stabilized Sigma 70-200 as well as a better camera. Until then I'll keep using the STM lens which is still better overall than the MK iii. Hey, I use it more often than the nifty fifty and the kit 18-55, so that should tell you something; the IQ is superior.

Thanks for reading!

Nevermind. The greatest difference between them that I cannot match in camera raw is the color noise. Seems the STM suffers with severe color noise in a very destructive way. If it wouldn't, the old MK iii would not stand a chance. I'm starting to wonder if I have a got a bad copy of the STM lens...