RF 70-200 or EF 70-200 with Converter for EOS R

ZX11 wrote:

RDKirk wrote:

ZX11 wrote:

I don't like the air pump design of the new RF 70-200 and its far higher price for the same image quality. To me, the EF 70-200 on the EOS R is a better choice. To each their own.

Interestingly, nobody seems to be reporting problems with the "air pump" design for the 24-70 or the 24-105...and it hasn't been a problem for decades. It appears to be a design Canon perfected a long time ago.

After reading Roger Cicala's disassembly report on the RF 70-200, I have no reason to doubt its solid mechanical prowess.

https://www.lensrentals.com/blog/2019/12/the-not-very-long-awaited-teardown-of-the-canon-rf-70-200mm-f2-8-is/

I have seen the video on youtube.

Hasn't been a problem for decades? The EF-S 17-55 f/2.8 does have a problem with dust getting in it due to the huge volume of air it pumps in and out as it zooms. It is not a decades old design. Similar dust with the EF 24-105.

No other air pump lenses get dust in them? Seems there are plenty of youtube videos about getting dust back out of Canon's air pumps.

I do not have to like the RF's air pump design just because it is the newest greatest hip thing. I do not think Canon was mistaken when they designed the all internal design on the EF 70-200 f2.8 and the EF 70-200 f/4.

I don't like fiddling with the lock on the RF 24-105 that is necessary for its air pump design. Do I have to like it too? I don't like the extra rotation range the RF 70-200's zoom ring has. The extra rotation needed to move the RF 70-200's large front element, entire barrel, hood, and the kitchen sink, forward and back.

I like the non-pumping, non-moving inner barrel, and thinner design of the EF 70-200. The EF is solid, sealed, and proven reliable. My choice. To each their own.

Read what Roger Cicala says in the comments:

OK, I'm not commenting on 'will it resolve' because I'll go on a 20 minute rant. Of course it will resolve.

Biggest dusters: 85 f1.2, 105mm f1.4s, 70-200 f/2.8s, 150-600s are fast horses. The biggest variable to 'how dusty is it' is probably 'how much do the front and rear elements magnify it'.

To be fair, in olden times some extending barrel zooms (Canon 100-400 old version, Sigma Bigma) were the dustiest. Like so many things, progress was made. I believe that progress is more like "we know the front element is going to magnify, we know there is air flow, let's design the air flow so it doesn't pool under the front element", but I don't know for sure.

Here's what I know for sure:
Every lens has air flowing through it, there are no air-tight lenses.
Air has dust in it.
Dust in air likes to settle on solid objects.

That glass stuff in your lens makes things look bigger, smaller, sharply in focus and sharply out of focus. Including what's inside the lens.

When you take a lens apart to clean out dust it's interesting how the horrid dust you saw on the second element almost disappears when you take the first element off.

When you take apart a lens to not clean out dust it's interesting how dusty the inside might be even though you didn't really see it.

There is generally less dust (not no dust) in lenses that we just opened new in box, too.

I sum this up in Roger's Rule #63: If you don't see dust in your lens, you don't have a bright enough light.

Per what he sees, the current crop of non-pumping 70-200 f/2.8's are already gathering a lot of dust inside. He also listed a a couple of large prime lenses (which don't zoom at all) and the 150-600's as among the worst.

All lenses will get dust inside. The issue is how much the front and rear elements in a lens magnify the dust.