Around Tucson

[Rodney9]

Nice shots, the candles is my favourite.

[Alan T]

mtngal wrote:

.....there's actually physics and mathmatics behind it all and you can compute what your DOF would be - but that's way beyond where I want to go.

If anyone wants the calculation done quickly & easily for them, I just remembered I stored this excellent website as a 'Favorite' years ago, and to my delight the site is still there...

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

In shots where you're wanting the background to be blurred, or not, the concept of 'hyperfocal distance' is useful. That's the distance you should set so that everything from there to infinity will be reasonably sharp. If you don't want the distant background to be sharp, you need to focus nearer than that.

Someone asked the same question in the recent thread...

http://forums.steves-digicams.com/fo...mp;forum_id=78

...and in the second post in that thread I attempt to explain why it's a lot more difficult to get selective focus with small digicams than it used to be withfilm. However, itshould still benice & easywitha K10D.

When I used an SLR, its Tamron lenses had a helpful set of curved lines engraved on the barrel, different colours for different apertures, that indicated a rough depth of field for each distance at each level of zoom. If you wanted maximum depth of field, you put the 'infinity' marker on that line.

DodSLR lenses have these markings these days, and if not, why not?

[mtngal]

Alan - none of my modern lenses have them, while all of my old lenses do. In fact, the DA lenses don't have aperture rings, so no f numbers color coded to show the focus range. The only FA lens I have is an inexpensive Phoenix lens, and while it has an aperture ring, it doesn't have the colored marks - don't know if that holds true for the Pentax FA lenses.

[ishino]

mtngal wrote:

Alan - none of my modern lenses have them, while all of my old lenses do. In fact, the DA lenses don't have aperture rings, so no f numbers color coded to show the focus range. The only FA lens I have is an inexpensive Phoenix lens, and while it has an aperture ring, it doesn't have the colored marks - don't know if that holds true for the Pentax FA lenses.

None of my Pentax FA series lenses (35, 43, 50, 77) have this either. FA-J 75-300 does not either.