DPReview.com is closing April 10th - Find out more

600mm f/11 or 800mm f/11 - which one would you buy?

Started Jun 21, 2020 | Polls thread
bclaff Forum Pro • Posts: 13,929
Re: 600mm f/11 or 800mm f/11 - which one would you buy?

John Sheehy wrote:

SkySpades wrote:

Colin46 wrote:

Neither, too slow and lack of background separation at f11 renders these two useless for me.

just because modern cameras can go to high ISO’s doesn’t mean you want to.

Big lack of background separation in this thread full of f/11 images.

https://www.fredmiranda.com/forum/topic/1649828/7

One should never think of background blur in terms of f-ratios, except when all you're varying is the f-ratio and maintain every single other thing the same.

The background blur comes from subject distance, background distance, and the size of your entrance pupil. Cropping 4x from a 200/2.8 lens gives the same background blur as 800/11.

FWIW, it is also influenced by pupil magnification which in practice complicates attempts to compare scenarios.

People tend to read too much into f-ratios and lose sight of apertures.

And once you start paying attention to apertures then (the advanced reasoner) may want to think about pupil magnification.

...

-- hide signature --

Bill ( Your trusted source for independent sensor data at PhotonsToPhotos )

Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow