Interesting article on f1.4 versus f1.8
The article is 'lab' based but then says ...
"The main reason I can see to invest in a 50mm f/1.4 is that the extremely narrow depth of field creates a very desirable effect that, in some circumstances, leads to a desirable look and feel that can’t be measured in the lab."
Which is exactly I bought an f1.2 and f1.4
Lenses: Pentax DA 10-17mm ED(IF) Fish Eye, Pentax DA 14mm f/2.8, Sigma 17-70mm f/2.8, Pentax-A 28mm f/2.8, Sigma 30mm F1.4 EX DC, Pentax-A 50mm f/1.2, Pentax-A 50mm f/1.4, Pentax-FA 50mm f/1.4, Pentax-A 50mm f/1.7, Pentax DA* 50-135mm f/2.8, Sigma 135-400mm APO DG, and more ..
Flash: AF-540FGZ, Vivitar 283
The lab can do many things but it can't measure the intangibles (Simga 30 f1.4 being the prime example).
Apparently.
However, the basic message is correct. F1.7/1.8 lenses perform better than the f1.4 versions, at least in certain parameters. If you use the f1.4 for what it is intended for then it becomes superior to the f1.7/1.8 versions.
I find it dosconcerting that any writer can put "depth of focus" when he means "depth of field" but that aside, this is an interpretation of results from DxO so not original research.
However, the basic message is correct. F1.7/1.8 lenses perform better than the f1.4 versions, at least in certain parameters. If you use the f1.4 for what it is intended for then it becomes superior to the f1.7/1.8 versions.
I wasn't aware I'd portrayed it as original research.
Apparently.
I wasn't aware I'd portrayed it as original research.
Neither was I.
I find it dosconcerting that any writer can put "depth of focus" when he means "depth of field" but that aside, this is an interpretation of results from DxO so not original research.
However, the basic message is correct. F1.7/1.8 lenses perform better than the f1.4 versions, at least in certain parameters. If you use the f1.4 for what it is intended for then it becomes superior to the f1.7/1.8 versions.
well said John where do these strange phrases come from i was always taught from books or friends DEPTH OF FIELD not depth of focus etc
Depth of focus is a proper photography term, but it differs from depth of field.
IIRC It refers to the camera side of the lens, being the region in which the sensor/film can move without adversely affecting the results.
.
Pentax:K5ii, K7, K100D, DA18-55, DA10-17, DA55-300, DA50-200, F100-300, F50, DA35 AL, 4* M50, 2* M135, Helicoid extension, Tak 300 f4 (& 6 film bodies)
3rd Party: Bigmos (Sigma 150-500mm OS HSM),2* 28mm, 100mm macro, 28-200 zoom, 35-80 zoom, 80-200 zoom, 80-210 zoom, 300mm M42, 600 mirror, 1000-4000 scope, 50mm M42, enlarger lenses, Sony & micro 4/3 cameras with various PK mounts, Zenit E...
Far to many tele-converters, adapters, project parts & extension tubes etc.
.[size=11:].Flickr• WPF• Panoramio
However, whereas smaller formats have more and more depth of field, they have less and less depth of focus. This means that smaller formats need higher standards of precision. This is where the 110 film cartridge and Kodak Disc formats fell down, with their cheap construction and tiny formats.
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1569 posts
14 years
Victory Mansions
It centres around Canikon lenses but the general principle apply across brands.
link
Apparently.