Hello everyone. I am really starting to pick up some good pointers from this website especially with my landscape photography. I do have a question though. I have always used older SLR's before I just purchsed my N75 and they never had a "Depth of Field" preview button like my new camera does. I have read and read about what advantages this button serves but every thing I read doesn't make any sense. While shooting at the coast this past weekend I experimented with it while in Aperture priority mode. I noticed that while adjusting f-stops my viewfinder would be darker or lighter depending on f-stop. Can anyone explain this to me and shed some light?? I am very green in this field thanks!!

JM

Jasen M

The image goes darker because you are closing the aperture down to the f-stop you select. Whenever you compsose an image, you are viewing with the aperture wide open. It's only when you press the shutter that the lens aperture closes down to what you have set it at. The preview button lets you view the image in the true f-stop you are shooting at. Does that make sense?

edye

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-Albert Camus

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The thing to notice is not that it gets darker (that's just a side effect), but rather that more of the image will appear sharper or in focus when you press the depth of field preview button.

Try this: set the camera at its widest aperture, then press the DOF preview button while lookint through the viewfinder. You should see no effect whatsoever since the camera won't be stopping the lens down at all (the normal viewing aperture is the widest one and your selected aperture is also the widest).

Now set the camera to say, f/8 or f/11 and do the same thing. Not only will the image get darker since less light can now get through the smaller hole, you should see a change in depth of field between not having the preview button pressed and when you do press it. The camera normally is still showing you the image at a wide open aperture, but when you press the button it stops the lens down to your selected aperture.

At small apertures the image can get dark enough to make viewing difficult. in such cases it can help to allow your eyes time to adjust much like what happens when you walk into a dark room. If even this doesn't do it, throwing your jacket or something up over your head to block out the ambient light, much as large format shooters do

Bob Johnson
Earthbound Light
Nature Photography from the Pacific Northwest and beyond
http://www.earthboundlight.com

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Nature Photography from the Pacific Northwest and beyond
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Bob, As always it's a pleasure to get your input. I've gained some great pointers from you and you've helped my pictures a lot. You're website is great also. How much do you use the DOF button?? Can I realy on this to judge the amount of light entering the camera especially for landscapes?? Thanks again!!

JM

Jasen M

Thanks Jasen.

The DOF preview button is great for judging depth of field and I use it for a high percentage of shots.

It is not good for judging exposure at all though since the shutter speed is not factored in, only the aperture. The image may look dark to your eye, but with an appropriate shutter speed it won't look that way to the camera (or rather the film).

Bob Johnson
Earthbound Light
Nature Photography from the Pacific Northwest and beyond
http://www.earthboundlight.com

Bob Johnson - Earthbound Light - Nikonians Gallery
Nature Photography from the Pacific Northwest and beyond
Lots more new images!! - Weekly Phototips and Articles - RSS Feed

Jasen -

Another thing you might want to think about is hyperfocal distance - at least for landscapes if what you're interested in is reasonably sharp focus from near foreground and background. To learn about this VERY!! useful technique, check out the HFD link in the Nikonians Guides & HowTos

Good luck!

A BAD DAY BEHIND A NIKON (OR NIKON-HYBRID DSLR) BEATS A GOOD DAY BEHIND A DESK - Bob Tomerlin

A BAD DAY BEHIND A NIKON BEATS A GOOD DAY BEHIND A DESK - Bob Tomerlin
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