ist DS depth of field preview.

I am plodding through my manual here and it seems to have been written by a Martian or at least a non native English speaker. Some of the text is appalling and much just plain amateurish.

OK... dof.

I'm looking through my viewfinder and I half press the shutter. The camera is focussed. Now I move the switch over to the preview position. Can anyone tell me wha is supposed to happen apart from the little noise and the disappearance of the info in the viewfinder. I have taken many excellent pictures with quite shallow depth of field but what am I looking for in the viewfinder.???

Through the viewfinder you should get an idea of your depth of field- ie: whats in focus and what isnt.

Depth of Field preview stops down the lens to the working aperture, be it f8, f11 or whatever. So you can, in theory, see what is in focus and what is not. Then you view the image at full aperture when the lever is released again so you can get the brighter view to compose your picture or to manually focus more easily.

In practice, I think the screen is too small to judge depth of field and I prefer to use other methods - either the depth of field scale if the lens has one, or the rule of thumb that you focus about a third of the way into a scene to focus on the hyperfocal distance.

The hyperfocal distance is whwere you have the maximum depth of field from infinity to the closest distance, for a given aperture. If you want an expansion of that explanation, please let me know!

or for hyperfocal distance you could look here.

http://www.nyip.com/tips/tip_hyperfocl898.html

john

Thanks for that so far. Even if I have set a wide aperture to get a narrow depth of field, when I pull the lever across I see no change in the viewfinder image. What happens in the camera? If it's an optical viewfinder it will be the same won't it?

So then I take the picture and the depth of field is clearly apparent in the LCD image.

Any further help in understanding this?

Some people rave about DOF preview, and dismiss any camera that doesn't have it.

However, with the lens stopped down to f8 or so, it is usually far too dark (for my eyes, at least) to make out any significant difference in depth of field.

So, I never use it. On digital cameras, the LCD gives a far better indication. I believe DOF preview won't stay around much longer on digital cameras.

G

I had another play this afternoon and tried a wide angle view but focussed on something quite near. I then closed down the aperture and tried the DOF preview.

I did notice a difference. The background blurred in the dimmed screen.

I think my dificulty was that I was at my widest aperture in order to get a shallow dof and when I pressed of course the aperture couln't open any wider and thus I saw no change.

I have learned something here but I still wonder how the camera shows you this.

Thanks gang but I don't think I'll be using it that much.

I've many other questions to ask arising from my reading of the ridiculous manual but I'll spread them out.

perhaps I should volunteer to write the next on!

The manual is, let us say, challenging...There are sections where if I didn't know what they were talking about I would be utterly baffled....

When you press the DOF lever, the lens aperture stops down (closes) to whatever value you have set. This increases the DOF, so the background should have appeared sharper.

I think I'd suggest you try it in bright light, because the dimming does make the effect very hard to see, as has already been mentioned.

I have to agree that with smaller apatures F8 and smaller the depth of field preview is not much help. However I do find it an excellent tool with close up, work which I do a lot when I require a very limited depth of field for creative reasons with a very particular area in focus and the rest out of focus. Often just half a stop one way or the other makes a difference and can be seen easily with the depth of field preview at the larger apatures I use.

David Benson