Imagemaster wrote:
I owned several versions of the EF 100-400 and preferred the push/pull, but also had no problem with the twist model. Of course either zoom method will be more awkward with a larger and heavier lens such as the 200-800.
I know nothing much about the internal working of lenses, so this is just my theory.
Whether it is a zoom or prime, are not glass elements moving closer and further apart when zooming or focusing? If so, does that not mean there are pressure differences taking place between the glass elements? Since none of these lenses are vacuum-sealed as far as I know, does that not mean all of them are prone to trying to suck dust into the low-pressure areas, and the amount would depend on how well sealed the lens would be?
This is my reason from experience for preferring a push pull external zoom over a twist external like the 100-400mm mk2 and the 100-500mm and both RF70-200's.. I've been leading bald eagle photo workshops for many years. Back when I had the 100-400mm mk1 I would take that and a EF500mmF4. When the 100-400mmmk2 came out I didn't get one right away and a friend let me borrow his for the tour since I was getting ready to buy one. When photographing the eagles they come from quite a distance. to very close in an instant. I had no problem at all keeping them framed perfectly with my push pull 100-400mm but found in to be very difficult with the twist zoom. Really liked the optics and IS in the new 100-400mm but nothing else. I never purchased one even though I moved on from the push pull. I went to using the EF70-200mm F2.8 with converters. At least you had a reasonable zoom throw that was manageable. Also when I shot sports with Reuters some events (hockey) you are in a fixed position twist external zooms were quite difficult to use compared to a IF zoom.
So in my experience as far as fast and accurate zoom and staying on intended subject Push/Pull zoom > Internal zoom > external twist zoom. But overall I think I'd take the internal zoom as implemented by Nikon and Sony with the 70 degree zoom though
Nov 05, 2023 at 06:51 PM
Previous versions of drobertfranz's message #16384502 « Canon 200-800? »
