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Full Version: DOF Preview--Explain Please?
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The DSLR I'm buying in the morning has been lightly criticized for not having a depth of field preview button.
This struck me as odd.
Forgive me for not having any DSLR experience, but I always thought that since you were looking through the lens any DOF information would be visible.

So my theory is that DSLRs leave the aperture wide open so that you can better see what you're shooting in marginal light, and also that the autofocus system has the best chance of getting it right with the extra light.
Therefore, the aperture only closes to where it's set when you press the shutter button.
Is this correct?

I'm not worried about not having DOF Preview--I think I have a good feeling for what apertures will give me the results I desire in any given situation.

In what situations have you found this feature to be important?
Hello Keith, you understand correctly what SLRs do. You view the objects wide open and the lens stops down only when you press shutter. This is to give you a good view of the object. Ever tried to look at an object through a lens stopped down to f/32? It is not very informative. The stopped down feature is useful when:
a) you wish to isolate a subject by selecting low DOF. You wish to make sure that the object you wish to have in focus are but the objects you do not are not.
b) when shooting close-up, the DOF is less and you want to make sure that you have enough.
c) under insufficient light conditions when you do not wish to increase ISO (noise) or lower shutter speed (movement artefact), but wish to have sufficient DOF
d) when you have an object in the foreground and object in distant background and you wish to make sure that all that isin focus.

I am using DOF preview less and less, because I find it hard to judge from what I see in the viewfinder, let alone on the bleached out LCD what is and is not in focus. Things lood different on 11"x14" than in a viewfinder with the lens stopped down. Check out whether you can see it at selected appertures and if you think you can, it may give you an edge setting up a photo. If you think it is hard to tell, do not fret about not having it. That is may take on it anyway. Pavel

You've got it right, the aperture doesn't close down until the photo is taken, for all of the reasons you've mentioned.

But the reality is that there are two massive differences between film and digital cameras. 135-film gives nice, big, bright viewfinders, letting the photographer have a good idea of the photo that they're about to spend money on. Reduced-frame DSLRs have small, dark viewfinders that give only a rough idea of what the photo will look like, but you can look at the actual image for free just seconds later.

I've only used a DOF preview button a couple of times, and for it to be meaningful the camera has to be on a tripod. If the camera's on a tripod, it's easy to chimp and re-shoot if needed. I wouldn't worry about its absence on the Alpha.

Went to the Sony Style store today and that was the first time I actually looked at the hotshoe.
&*$%#@$! proprietary design!!!
I told the guy this was a deal-breaker and left.
Fumed for a few hours until I could get home and poke around online.
And who else but Gadget Infinity has the required hotshoe adapter!
So my manual flash and Gadget Infinity wireless triggers will work.

Going back tomorrow, but there's another problem:
Which color?
Sony Style stores have an exclusive "gold" finish on the Alpha300.
So, black or "gold"?
Keep in mind that I live in Texas and shoot at night, and like to be different.
Which would you prefer?
[Image: DSLRA300KN.jpg]
Take different photos and go for ordinary-looking camera Keith or else get a nice purple pouch for it. Pavel
SonyStyle's episode of "Dude, Pimp My Camera" must be finished filming. I'm with Pavel on this one, go with basic black: and I'm the guy with two bright orange shoulder bags. I've seen plenty of Silver SLRs in my time, and they invariably chip or wear through to a grody grey/beige plastic. Black ones still scuff, but the colour is simply the plastic, and they still look fine. And think how dumb your lenses will look on the gold. Just Say No To Bling.
It was a shock at the time to discover this new color of camera when I was in the midst of much more important decisions.