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05-02-2009, 01:06 PM   #1
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MrEspie's Avatar

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Location: University of Waterloo, ON
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Red marks on SMCP-M 1:2.8 28mm

Hey guys,

I just recently bought the SMCP-M 1:2.8 28mm and have one slight question: why are the 8 on the aperture ring and the 10m mark on the focus ring marked in red? Is that to mark where the lens is its sharpest? Or perhaps was this to give less-experienced users a sort of 'point and shoot' mode? I'm really interested in knowing the answer.


05-02-2009, 06:25 PM   #2
8540tomg's Avatar

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Hi Al,

I think the following link should explain those mysterious red marks on your 28mm.

PENTAX DSLRs: DSLR Photography lessons - Lesson 3. Depth of Field / Hyperfocal Distance.

Tom G
05-02-2009, 09:03 PM   #3

Join Date: Feb 2009
Location: Alameda, CA
Posts: 3,205
QuoteOriginally posted by MrEspie Quote
why are the 8 on the aperture ring and the 10m mark on the focus ring marked in red?
It's 10ft, not 10m.

Align the red 3m (10ft) on the distance scale with the distance indicator mark.

Set aperture to (red) f/8.

Look at the left 8 and the right 8 on the DoF indicator: anything between 5ft (1.5m) to infinity will be in focus.

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