Grogly

Grogly

Lives in United States United States
Works as a Ex- Physicist now Telecommunications Engineer
Joined on Aug 20, 2005
About me:

Bodies:
Canon EOS 5D Mark III
Canon EOS M
Canon EOS Elan IIE
Canon G10

Lenses:
Canon EF 50mm f/1.4 USM
Canon EF 28mm f/1.8 USM
Canon EF 17-40mm f/4 USM L
Canon EF 24-105mm f/4 IS USM L
Canon EF 70-200mm f/4 IS USM L
Canon EF-M 22mm f/2 STM
Canon EF-M 18-55mm f/3.5-5.6 STM IS
Kenko Pro300 2x Teleconverter

Flashes:
Canon 580EX II
Canon 420EX

Comments

Total: 2, showing: 1 – 2
On What is equivalence and why should I care? article (2020 comments in total)
In reply to:

Grogly: DPreview has done a disservice to their readers with this article. Equivalence between formats comes down to only one thing, depth of field. An f/2.8 lens is ALWAYS and f/2.8 lens for exposure. Here is why this is true without all the technical mumbo-jumbo. Let’s do a thought experiment.

Suppose you went down to your local camera store and bought a hand held light meter to use with your various format cameras. Once you get the meter home, you discover that there is no setting for your 6x9 medium format camera or your 35mm digital camera or your 16mm film movie camera. There are only settings for ISO, f-stop and shutter speed. Why? Because for exposure, all that matters are those three settings, completely independent of what format you use. By the way, that light meter still works with your digital cameras, provided their ISO/SS/F-stops are correctly calibrated.

So feel free to discuss the merits of DOF, or whatever other comparisons between formats, but leave exposure out!

Quote from the article:

"But surely F1.2=F1.2=F1.2?

Yes, it is. But F1.2 is not equivalent to F1.2 across different formats."

Wrong! Exposure is exposure, f/1.2 or f/8. Just discussing this only obfuscates the equivalence thing unnecessarily.

Direct link | Posted on Jul 7, 2014 at 13:50 UTC
On What is equivalence and why should I care? article (2020 comments in total)

DPreview has done a disservice to their readers with this article. Equivalence between formats comes down to only one thing, depth of field. An f/2.8 lens is ALWAYS and f/2.8 lens for exposure. Here is why this is true without all the technical mumbo-jumbo. Let’s do a thought experiment.

Suppose you went down to your local camera store and bought a hand held light meter to use with your various format cameras. Once you get the meter home, you discover that there is no setting for your 6x9 medium format camera or your 35mm digital camera or your 16mm film movie camera. There are only settings for ISO, f-stop and shutter speed. Why? Because for exposure, all that matters are those three settings, completely independent of what format you use. By the way, that light meter still works with your digital cameras, provided their ISO/SS/F-stops are correctly calibrated.

So feel free to discuss the merits of DOF, or whatever other comparisons between formats, but leave exposure out!

Direct link | Posted on Jul 7, 2014 at 13:36 UTC as 356th comment | 11 replies
Total: 2, showing: 1 – 2