DLO can sometimes do miracles !

Yup. I'm positive. However, I'm not quite sure that DLO optimization is effective. I moved the distance and sharpness sliders (left/right) but couldn't see any difference at all. I'll have to redo this later when I'm home to see if there's any improvement at all. I can also confirm which Canon lens DLO profile that I installed yesterday.

morph2_7 wrote in post #15560579
I can also confirm which Canon lens DLO profile that I installed yesterday.

Yes, it would be useful to know, which is the parameter that Canon selected the substitute upon.

morph2_7 wrote in post #15560548
That is what I meant to say, with DLO, without DLO.

Btw, I played around with DLO yesterday using my Tamron 17-50mm lens. DLO feature was disabled at first. When I clicked Update button, one of Canon lens in the list was in bold font (I can't remember which one at the moment). I supposed that is the suggested lens DLO profile to download so I installed that. DLO feature got enabled after installing the new lens profile. I didn't have to go through editing EXIF to trick DLO into thinking that it is a Canon lens.

All that means is that the same Maker's Notes code number represents that Canon lens and the Tamron 17-50. DPP saw the number and thought you have the Canon lens. The same thing happens with my Sigma 15-30 which DPP thinks is a Canon 17-35 F/2.8L. However, as yb98 has discovered, that does not mean that it is the best choice for corrections to be applied to the Tamron.

Here is what ExifToolGUI shows for that lens:

From this table : http://www.sno.phy.que​ensu.ca …ftool/TagNames/​Canon.html

We can see that the Tamron 17-50 has the same first 2 numbers as the Canon 35-80. However the 35-80 is not listed in DLO. So, I'm curious to see which lens DLO has selected for the 17-50 ?

37 = Canon EF 35-80mm f/4-5.6 or Tamron Lens
37.1 = Tamron 70-200mm f/2.8 Di LD IF Macro
37.2 = Tamron AF 28-300mm F/3.5-6.3 XR Di VC LD Aspherical [IF] Macro Model A20
37.3 = Tamron SP AF 17-50mm f/2.8 XR Di II VC LD Aspherical [IF]
37.4 = Tamron AF 18-270mm f/3.5-6.3 Di II VC LD Aspherical [IF] Macro

Also from the previous table, we can see that the Sigma 15-30 has the same first 3 numbers as the Canon 17-35 F/2.8L. So it seems that DLO takes into account only the integer part of the number.
But still I don"t understand because if for the tamron 17-50, DLO think it's a Canon 35-80, normally it should be disabled since there is no profile for the 35-80...

169 = Canon EF 17-35mm f/2.8L or Sigma Lens
169.1 = Sigma 18-200mm f/3.5-6.3 DC OS
169.2 = Sigma 15-30mm f/3.5-4.5 EX DG Aspherical
169.3 = Sigma 18-50mm f/2.8 Macro
169.4 = Sigma 50mm f/1.4 EX DG HSM
169.5 = Sigma 85mm f/1.4 EX DG HSM
169.6 = Sigma 30mm f/1.4 EX DC HSM
169.7 = Sigma 35mm f/1.4 DG HSM

yb98, I won't be home for at least another 2 hours. As soon as I can access DPP software on my home PC, I will give you an update of DLO profile that Canon picks (highlighted in bold font) for Tamron 17-50mm.

Ok, I'm looking at DPP Add or Remove lens data. DPP suggested EF 28-70mm F2.8L USM for my Tamron 17-50mm F2.8 lens. That's what I installed.

Another thing I'd like to mention is that I do see significant difference when I move Setting slider (left/right) from 0 to 100. The difference is clearly noticeable on the edges of the picture. Not so much in the center. I must be looking at the center yesterday.

ok I see.
Actually, there are 3 tamrons 17-50 and one of them corresponds indeed to the Canon 28-70 2.8L (161).

Now the question is, why Canon affected to some third-party lenses the same numbers as some other canon lenses ? does it mean that these lenses have some common characteristics

161 = Canon EF 28-70mm f/2.8L or Sigma or Tamron Lens
161.3 = Tamron AF 17-50mm f/2.8 Di-II LD Aspherical

37 = Canon EF 35-80mm f/4-5.6 or Tamron Lens
37.3 = Tamron SP AF 17-50mm f/2.8 XR Di II VC LD Aspherical [IF]

137 = Canon EF 85mm f/1.2L or Sigma or Tamron Lens
137.11 = Tamron SP 17-50mm f/2.8 XR Di II VC

Mine is the non VC version (161.3). It makes sense DPP offers EF 28-70mm to download/install.