I usually use rechargables in my K100D, but when on holiday a few weeks back, I ran low and bought some lithium ones from a shop - they've now been in the camera for three weeks and are still going!
Having four AA batteries in the camera definitely makes it a bit heavier than some other models, but as previously mentioned, it really is handy to be able to pick up emergency batteries anywhere when your rechargables run out.
And I back the K200D too - looks great!
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Pentax K100D Super | Tamron 18-250mm | Pentax SMC P-FA 50mm F1.4
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