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Giovanni Frescura
08-05-2012, 08:28 AM
Gello
I use Canon Mark IV and 7d normally with Canon 300 2,8 and 500 f.4
I have a question about deph field.
Sometimes the problem with long lens is non have the object (expeccially mammals) all in focus.
I think that using a more deph field (minimum f.8) is possible have less problem. The new cameras haven't problem with iso so could better al ittle more rumor but all in focus
What you think about?
Thanks

John Chardine
08-05-2012, 05:45 PM
Hi Giovanni- Certainly a smaller aperture will give you greater depth of field. However, depending on the distance of your subject and its depth, you may not be able to get the whole of the subject in focus and this is OK in my opinion. For example, a bird in flight with wings outstretched, one towards you and one away, it is unlikely that you will render the wing tips in focus. With perched bird portraits its not absolutely essential to get the tail in focus so long as the eye, head, and parts of the body are. When I am making a portrait of a bird with a long bill and the bird is facing you, I sometimes try to get the bill tip in focus as well as (of course) the eye. In this situation I might use f8 or f11, and increase the ISO so that I get a shutter speed that I need. However, often in portraits, the eye and head are so strong that a soft bill-tip is acceptable (in my opinion again).

If I were you I would try setting the f-stop for the depth of field you want, then set the ISO so that you are getting the shutter speed and exposure you are looking for. ISOs up to 1600 should work well for you with your cameras, and if you get some noise there are ways to reduce this in processing.

There are several Depth of Field calculators on the web. I like this one:

http://www.dofmaster.com/dofjs.html

You can plug in your lens focal length, typical shooting distance and see what you get for different f-stops. This will show you if you are even in the ball-park of where you want to be for the subjects you are shooting.

Graeme Sheppard
08-05-2012, 08:25 PM
The best thing is to give it a try and make up your own mind. Noise is very subjective - if you look at old photos there is grain visible but people accept it and even appreciate it.

My opinion is that you should choose your subject, choose your aperture size to get the depth of field wanted, choose your shutter speed to keep it sharp, then put ISO up as high as necessary.
(and change this routine whenever specific shots suggest it).

Personally, if I can get a bird full frame and sharp, I'm happy with ISO 6400 on my 7D, but I'm not selling my photos! If you have to crop, noise becomes more of a problem and distraction in my opinion.

Here is a recent photo I really like of mine, but it won't win any awards and I probably just like it for emotional reasons. But since I photograph for myself and my wife, that's fine :)

http://aportraitofnature.com/wp-content/uploads/2012/07/Mountain-Scops-Owl.jpg

Mountain Scops-Owl, 7D + 70-300L at 300mm, ISO 12800, shutter speed about 1/30 lit with a torch in pitch black.
btw, I put this here to illustrate that the noise can be acceptable.

David Stephens
08-08-2012, 09:31 AM
Gello
I use Canon Mark IV and 7d normally with Canon 300 2,8 and 500 f.4
I have a question about deph field.
Sometimes the problem with long lens is non have the object (expeccially mammals) all in focus.
I think that using a more deph field (minimum f.8) is possible have less problem. The new cameras haven't problem with iso so could better al ittle more rumor but all in focus
What you think about?
Thanks

This is just one of the advantages of the latest generation of DSLRs that have exceptional high-ISO performance. The 5D MkIII and the 1D X are exemplary. I own the 5D3, but now I'm seriously considering the 1D X after seeing some amazing wildlife shots taken at ISO 16,000, something that I couldn't imagine a year or so ago.
116835

When the subject is too close, particularly with the 500/f4, then you can only get the eyes in focus, which is often enough.