Depth of Field Preview

[robertwsimpson]

I can vouch for that. for the longest, I was taking pictures at f22 and wondering why they were all coming out crappy. it's strange, but the entire picture is sharper at f11 than at f22.

 

[coreduo]

I know I tried 30 seconds and f/40 or 45s in my D40X. It should had been a perfect picture with a good DOF if I used a small tripod on toy soldiers, which I had discarded. I will try it again and I'll post it. Anyway, I am not a professional nor an amateur but only a beginner. I'll give some time to it and post it.

 

[Garbz]

May I ask which lens? The only lens of mine which does something like that is a Macro Lens. In which case the aperture numbers mean something quite different than the actual size of the iris. We had a physics guru here a while ago who explained it all beautifully.

 

[Overread]

May I ask which lens? The only lens of mine which does something like that is a Macro Lens. In which case the aperture numbers mean something quite different than the actual size of the iris. We had a physics guru here a while ago who explained it all beautifully.

Hmm isn't that something to do with the fact that modern (I think its more modern macro lenses but it might be all of them) macro lenses effectivly stop down the camera as you start to focus into the macro magnifcations. So that when at 1:1 the actual aperture is something like f5.6, even on a lens which is f2.8 and wide open. I think its something that gets reported for Nikon cameras actually, though canon don't report this (wide open is still reported at f2.8 even though the viewfinder images has dimmed)

 

[coreduo]

May I ask which lens? The only lens of mine which does something like that is a Macro Lens. In which case the aperture numbers mean something quite different than the actual size of the iris. We had a physics guru here a while ago who explained it all beautifully.

It is a Nikon micro labelled 'macro' by other brands. Because I am so preoccupied with 'so many projects' and scattered brain, I did not try to remember how many mm is the lens. But I am sure it is a micro.

By the way, I saw the magazine. DigitalPhotography: The Beginner's Guide to Digital Camera. I stood to be corrected. Corresponding shutter speed for f/45 is 1/4 second. Sorry guys!

 

[Overread]

By the way, I saw the magazine. DigitalPhotography: The Beginner's Guide to Digital Camera. I stood to be corrected. Corresponding shutter speed for f/45 is 1/4 second. Sorry guys!

Ok I might be getting something mixed up here -but as far as I was aware the shutter speed for a given aperture is based upon the lighting availble at the time of the shot and the ISO of the camera/film.

 

[Garbz]

I'm not entirely sure if it's the physical aperture or a "reported" aperture. The iris in the lens is not automatically smaller when you zoom in but less light is transmitted through the lens. Now this design is the same for all macros, however as you zoom into 1:1 my Micro-Nikkor 105mm f/2.8 will report apertures from f/5.6 to f/56 or thereabouts, but the Vivtar Series 1 105mm f/2 reports f/2-f/22 regardless of zoom.

The camera responds accordingly with the correct shutter due to recording light but I think it effects the "3D Matrix Metering" algorithms somehow. This would be similar to an 70-200 with a Nikon 1.7x TC reporting f/5.6 as the max aperture, whereas with a Kenko Pro 300 1.7x TC reports f/2.8 despite the light actually being 2 stops lower.


What I'm saying is I don't think the image was "really" shot at f/45