Poor focusing on the 35mm Prime

Paul77

I have recently purchased the prime lens and am happily experimenting until help arrives (the cheat sheets)!

I have noticed a couple of times when I first look through the view finder, the entire frame is out of focus, so have to half press the shutter to begin with before I take any further steps.

Can this be normal or do I need to have it looked at?

I only ask as I haven't noticed this on my other kit lenses.

I would be very grateful of any advice.

Cheers,
Paul

Haggis

Set focus to AFA.

bruto

It is normal. On the kit lenses, the depth of field is considerably greater, and the amount of focusing they need to come right may not show so conspicuously.

The AF system is designed to do all its viewing and focusing with the lens set wide open, even if you're shooting at a closed down aperture. The aperture is actuated only when you take a picture.

AF does not work all the time, but only when you push the shutter button part or all the way down. If it worked all the time, it would eat your battery up very fast.

As a result, when you look through the viewfinder, you're always seeing the shallowest depth of field the lens can offer, and until you push the button it remains unadjusted. So if any previous shot was shot at a different distance from what you're looking at, it will seem quite blurry and need refocusing. That's true of the kit lenses too, but it just does not show so obviously.

If the lens focuses correctly when you press the button, all is well.