[Josep]

Hi all, 

Is it possible to create a homemade MTF chart of a lens? Homemade meaning without buying any additional software or hardware.

I'm asking because I have the Sigma 15-30mm lens designed for Canon DSLR (quite an old lens) that I'm using with a Sony A7rIII and would like to know how it compares to modern lenses, and since it's difficult for me to rent or test those new lenses I thought that creating the MTF chart could be a way to compare the sharpness (other aspects I can compare more easily).

I know the Sigma 15-30 was reviewed here, but only with a much lower resolution Aps-c sensor. 

Well, also I'm asking because I'm an engineer (not optical of course) and I just like this stuff  

Thanks in advance for your answers.

[Brightcolours]

You will not be able to measure images you take without software, which knows the chart you use. If you use freely available software, you can't compare results with Optical Limits MTF results for so many reasons that I don't feel like listing them all.

But you can compare this lens with other lenses you have (/access to).

A cost free (open source) MTF software collection is called MTF mapper:
https://sourceforge.net/p/mtfmapper/home/Home/
https://sourceforge.net/projects/mtfmapper/

[Josep]

You will not be able to measure images you take without software, which knows the chart you use. If you use freely available software, you can't compare results with Optical Limits MTF results for so many reasons that I don't feel like listing them all.

But you can compare this lens with other lenses you have (/access to).

A cost free (open source) MTF software collection is called MTF mapper:
https://sourceforge.net/p/mtfmapper/home/Home/
https://sourceforge.net/projects/mtfmapper/

Thank you very much, that's precisely what I was looking for. It's a shame that those results can't be compared to the reviews here, but as you say I can compare them to other lenses I have, so I can work with that.

[Rover]

Thanks BC, maybe I'll take a stab at testing the lenses (however crudely) after all.