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Comment by johnriley posted on A few q's about the Sigma 30mm, eBay and Sigma sevice before I buy... at 29/05/2011 - 11:47
It's not that 1.4 lenses are difficult to focus it's that at apertures like 1.4 the viewfinder can't show a DOF that narrow, so you can be out of focus even though it looks in focus through the viewfinder.
I showed this effect to a shooting buddy recently with my Pentax A 50/1.2. I got him to look at and focus on a subject @ f/1.2 and asked him note teh DOF in the viewfinder and then note the DOF in the actual picture taken in the preview screen. he was actually shocked at the difference.
This is why if I'm going for maximum DOF I use the, say, f8 markers on a lens but actually set the lens to f11. This of course assumes that the lens does actually have DOF indicator markings. Most manual focus ones do. Most zooms do not.
Comment by johnriley posted on A few q's about the Sigma 30mm, eBay and Sigma sevice before I buy... at 29/05/2011 - 10:56
Comment by johnriley posted on FS: FA 31mm Limited in Black - mint at 29/05/2011 - 00:27
Comment by johnriley posted on WTB: Flash Sync cap at 29/05/2011 - 00:20
Comment by johnriley posted on K-5 Silver... Crashed at 28/05/2011 - 16:51
Comment by johnriley posted on K-5 Over-Exposure with flash at 28/05/2011 - 16:42
If the ISO is too high there is no aperture small enough to expose correctly.
Comment by johnriley posted on K-5 Over-Exposure with flash at 28/05/2011 - 14:15
The 43mm Ltd was supposedly made because Pentax decided the proper standard lens for 35mm cameras was around the 40mm mark
However, early lens making also took its traditions from Leica, which used available cine focal lengths, so 50mm was widespead. Something slightly longer is easier to make, so 58mm was often used for wide aperture standard lenses.
Relating this to the real world, a "standard" lens is one that comes closest to showing a scene as our eyes see it.
Comment by johnriley posted on Do we think there's any chance... at 28/05/2011 - 14:11
Comment by johnriley posted on WTB: Flash Sync cap at 28/05/2011 - 13:25
For my business cards I use a small leather wallet from around 1915, which also has spaces for stamps that happen to be exactly the right size for SD cards.
For any AA batteries I have a flip top container that housed cufflinks and is exactly the right size for 4 AA batteries.....
Comment by johnriley posted on WTB: Flash Sync cap at 28/05/2011 - 13:24


Obviously they mustn't have checked if the lens needed AF adjustment before doing the tests