YangMills

I adapt the Canon EF85 1.4L to my R bodies. It works flawlessly and gives the most beautiful rendering of any lens I own. Fantastic for portraits. I guess the RF85 1.2L would be even better but at ...

It’s the only use I have for the lens ring and only on my R7 which is probably the least used of my bodies. I set it to work with shutter button half press otherwise I kept changing it inadvertently.

I have both - got the OEM one then needed a second and decided to try the 3rd party one. Apart from the weather sealing and Wi-Fi they work and look  the same (3rd party finish is a little ...

I use the lens ring when  half pressing shutter release to set ec when in manual with auto iso on R7. It’s a bit of a pain because it’s different from the R5/6 as it lacks one of the dials.

I find the lens pens (branded “Lenspen”) work extremely well blow (or brush), lens pen, blow (or brush) again. They are particularly good for any greasy type dirt, which lens tissues just smear ...

Ok that figures in theory. In reality my non-OEM batteries perform in every respect at least as well as my OEM ones. Probably came out of the same factory.

I am not objecting to you measuring the performance of your lenses in any way that you see fit. I am objecting to your general statement that “MTF is horse feathers”. It might be of no use to you, ...

Seems so, which I agree is not the most exciting or productive pursuit. I simply don’t think of the resolution charts as MTF charts which to me always have been charts showing MTF as a function of ...

it’s not an MTF chart. It’s reporting resolution at a given MTF, not MTF. yes that’s correct, it’s reporting resolution limit at a given MTF,  not MTF. yes that’s also correct. It’s not even an MTF ...

Your first link doesn’t report MTF or CTF at all. It reports resolution limit according to some opaque criterion. The second chart reports CTF at 50lp/mm as a function of aperture for a number of ...

You are in fact estimating MTF (actually CTF) by eye.  And you called MTF a “load of horse feathers” which claim is itself a load of horse feathers.

The full MTF is two surfaces (meridional and saggital) in 3D space with the three axes being contrast, frequency and percentage field (or mm of field). Long before Canon started publishing MTF ...

I disagree with the notion that the Canon marketing charts are of no value. But I agree that one shouldn’t use them as the sole criterion for making buying decisions.

I still don’t understand why the advice to use only OEM batteries?

We can agree on the bolded statement.

You are simply wrong. Typical MTF charts show the contrast as a function of frequency.

This might be how Canon presents it for marketing purposes, but it is not the typical way that MTF is presented. The usual way is to present it as contrast versus frequency not at fixed ...

That’s how Canon does it for marketing but it’s not typical. Typically you would see the transfer function plotted against frequency with several curves - one on axis, meridional and sagittal  at ...

yes - that’s why lens designers and the complex lens optimisation programs they use rely fundamentally on MTF. But I guess you know better than the professional optical engineers who design the ...

Some of these are virtuous, but several have nothing to do with carbon footprint, eg., using OEM batteries, not using flash. Let’s not conflate all advice with carbon footprint issues.