03-25-2011, 06:47 PM
Yes, technically you're, of course, correct.
It's already a difficult topic so we decided to do it the simple way because it is more widely known that you loose about a stop.
cheers
Klaus
[quote name='jtra' timestamp='1300989287' post='7079']
Thank you Photozone for starting to include "Equiv. max. f-stops" in the reviews.
It brings attention to the fact that it is misleading to specify equivalent focal length along with non-equivalent relative apertures (thus breaking simple proportion: ApertureDiameter = FocalLength / FNumber). It is great that you specify both.
In recent Nikon 18-55vr review:
[indent]Equiv. focal length: 27-82.5 mm (full format equivalent)
Equiv. max. f-stops: f/5.0-8.0 (full format equivalent, in terms of depth-of-field - not speed)
[/indent]
Only slight detail: values should be f/5.3-8.5 since crop factor for Nikon DX cameras is 1.52, not 1.4.
It could be also improved by linking to this excellent article (or write some shorter explanation on your site): [url="http://www.josephjamesphotography.com/equivalence/"]http://www.josephjam...om/equivalence/[/url]
[/quote]
It's already a difficult topic so we decided to do it the simple way because it is more widely known that you loose about a stop.
cheers
Klaus
[quote name='jtra' timestamp='1300989287' post='7079']
Thank you Photozone for starting to include "Equiv. max. f-stops" in the reviews.
It brings attention to the fact that it is misleading to specify equivalent focal length along with non-equivalent relative apertures (thus breaking simple proportion: ApertureDiameter = FocalLength / FNumber). It is great that you specify both.
In recent Nikon 18-55vr review:
[indent]Equiv. focal length: 27-82.5 mm (full format equivalent)
Equiv. max. f-stops: f/5.0-8.0 (full format equivalent, in terms of depth-of-field - not speed)
[/indent]
Only slight detail: values should be f/5.3-8.5 since crop factor for Nikon DX cameras is 1.52, not 1.4.
It could be also improved by linking to this excellent article (or write some shorter explanation on your site): [url="http://www.josephjamesphotography.com/equivalence/"]http://www.josephjam...om/equivalence/[/url]
[/quote]