Totally silly question about using DOF preview button

[Cacatfish]

Hi all, so I have been messing around with my sort of new to me Nikon F3, which I am enjoying quite a bit. And Im going through the process of acclimation which has brought up questions about how one could use DOF preview.
In the past I have always pressed the button, figured "oh I want a little more or less DOF" then released the button, adjusted aperture and re checked. That seems to work pretty well, especially as the finger I use to press the button would be the same I use to adjust aperture. But then I was playing around with using my other hand to hold the button pressed while scrolling through apertures until I like the DOF. Im assuming this cant harm the lens right? Is this how anyone else uses the button. Thanks.

 

[albada]

Changing aperture while the lens is stopped down is harmless. In fact, lenses from the early 60's often had an M-A (manual-auto) slider. In the M-position, the lens was always stopped down, and was thus always in DOF-preview mode.
Mark Overton

 

[Kirks518]

Changing aperture while the lens is stopped down is harmless.
Mark Overton

Ditto. Canon even has DOF Preview Lock on a number of their bodies that allow you to do it with one hand.

 

[Greg Heath]

There are never any silly questions...

 

[Cacatfish]

Great info, thanks!
I like the idea of a dof lock button.

 

[AgX]

Before there was such as automatic-diaphragm (camera on releasing automatically stopping lens down to preset aperture) there were lenses that got a button for this action that covered the release button on the body, by this acting as release button too, but first stopping down the lens at releasing. This in a way yielded also a DOF control.

 

[RalphLambrecht]

There are never any silly questions...

Well;I have heard and asked a few but on the subject of preview buttons;they are mostly useless in my opinion. the image is always too dark to be trusted

 

[narsuitus]

...preview buttons;they are mostly useless in my opinion. the image is always too dark to be trusted

That has also been my experience and my opinion.

The depth-of-field scale on the lens has been a more reliable tool for me.

 

[480sparky]

There are never any silly questions...

The only silly question is the one that never gets asked.

 

[Cholentpot]

I use it all the time to meter my non AI-S lenses. Very useful.

 

[blockend]

on the subject of preview buttons;they are mostly useless in my opinion. the image is always too dark to be trusted

True, and the greater the need to know the extent of focus, the gloomier and more unreadable the viewfinder becomes.

 

[AgX]

Not only the largest DOF is of interest but also the more shallow ones, and those are related to larger apertures.

 

[480sparky]

Well;I have heard and asked a few but on the subject of preview buttons;they are mostly useless in my opinion. the image is always too dark to be trusted

For 35mm SLRs, yes. Not so much for large format. Especially when one shoots with a quality loupe.