where is the best way to put focus.

SoulAsylum · 04-14-2011, 06:58 PM

i like landscape shooting, but a freshman.
when l shot a landscape with wide lense,DA 12-24, I always put the focus in infinity， which is the best way or not?

**BigDave** · 04-14-2011, 07:38 PM

Soul:

With a lens like the 12-24, you have so much depth of field, you almost don't HAVE to focus!

But given the choice, it is best to focus on the part of the image that is closer to you and let the DoF carry to the horizon (infinity). If you leave it on infinity, you can risk loosing sharpness on the closer parts of the image.

Regards,

SpecialK · 04-14-2011, 09:17 PM

About 1/3 the way in. If you focus at infinity, you sort of "waste" some depth of focus on the far side of infinity, wherever that is :-)

Of course, that assumes you want as much in focus as possible at the given f-stop. If you want a tree in the foreground to pop, that's where you focus.

SoulAsylum · 04-14-2011, 09:30 PM

Originally posted by BigDave

Soul:

With a lens like the 12-24, you have so much depth of field, you almost don't HAVE to focus!

But given the choice, it is best to focus on the part of the image that is closer to you and let the DoF carry to the horizon (infinity). If you leave it on infinity, you can risk loosing sharpness on the closer parts of the image.

Regards,

Thanx for your reply and pardon my English comprehension, I am puzzled that putting the focus on the hyperfocal position is the way guaranteeing all the things in this photo look clear, i remember the book said that.
another puzzle is about your first advice. what the distance of a focus you put can also guarantee the dof carried to horizon and the most sharpness?
in this picture i shot yesterday, i put the focus on the second tower ot this bridge, which i think it's enough to guarantee the sharpness. but which turns out not very sharp as i tought to be. Maybe, it is related to the weather condition, it was foggy yesterday. and I also think maybe there is another reason on focal issue.

Adam · 04-14-2011, 10:06 PM

This isn't a troubleshooting question. Moved.

**BigDave** · 04-15-2011, 09:11 AM

Originally posted by SoulAsylum

in this picture i shot yesterday, i put the focus on the second tower ot this bridge, which i think it's enough to guarantee the sharpness. but which turns out not very sharp as i tought to be.

Soul:

the image is not posted (nor a link) so there is nothing to look at to see what the problem was.

And since you are aware of hyperfocal distance. generally, this is the way to go, just remember to pay attention to the f numbers when "guestimating" (guessing and estimating) the HFD. Not all lenses provide this information though, and the use of Depth of Field preview can be very useful, if your camera has this. As SpecialK stated, about a third of the way into the depth of the image is a good "rule of thumb" (general rule) to use when picking a point of focus. Generally speaking, the relationship is DoF extends one third in front of your point of focus and 2 thirds , or more, beyond. However the further you stop down, to the high f numbers, the more the depth of field extends beyond your point of focus toward or to infinity.

Regards,

04-14-2011, 06:58 PM	#1
SoulAsylum Junior Member Join Date: Jan 2011 Posts: 25	where is the best way to put focus. i like landscape shooting, but a freshman. when l shot a landscape with wide lense,DA 12-24, I always put the focus in infinity， which is the best way or not?

04-14-2011, 10:06 PM	#5
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,609	This isn't a troubleshooting question. Moved. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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04-14-2011, 07:38 PM	#2
BigDave Site Supporter Join Date: Sep 2010 Location: Hudson Valley, NY Photos: Gallery \| Albums Posts: 2,626	Soul: With a lens like the 12-24, you have so much depth of field, you almost don't HAVE to focus! But given the choice, it is best to focus on the part of the image that is closer to you and let the DoF carry to the horizon (infinity). If you leave it on infinity, you can risk loosing sharpness on the closer parts of the image. Regards,

04-14-2011, 09:17 PM	#3
SpecialK Pentaxian Join Date: Dec 2006 Location: So California Photos: Gallery Posts: 16,482	About 1/3 the way in. If you focus at infinity, you sort of "waste" some depth of focus on the far side of infinity, wherever that is :-) Of course, that assumes you want as much in focus as possible at the given f-stop. If you want a tree in the foreground to pop, that's where you focus.

04-14-2011, 09:30 PM	#4
SoulAsylum Junior Member Join Date: Jan 2011 Posts: 25 Original Poster	Originally posted by BigDave Soul: With a lens like the 12-24, you have so much depth of field, you almost don't HAVE to focus! But given the choice, it is best to focus on the part of the image that is closer to you and let the DoF carry to the horizon (infinity). If you leave it on infinity, you can risk loosing sharpness on the closer parts of the image. Regards, Thanx for your reply and pardon my English comprehension, I am puzzled that putting the focus on the hyperfocal position is the way guaranteeing all the things in this photo look clear, i remember the book said that. another puzzle is about your first advice. what the distance of a focus you put can also guarantee the dof carried to horizon and the most sharpness? in this picture i shot yesterday, i put the focus on the second tower ot this bridge, which i think it's enough to guarantee the sharpness. but which turns out not very sharp as i tought to be. Maybe, it is related to the weather condition, it was foggy yesterday. and I also think maybe there is another reason on focal issue.

04-15-2011, 09:11 AM	#6
BigDave Site Supporter Join Date: Sep 2010 Location: Hudson Valley, NY Photos: Gallery \| Albums Posts: 2,626	Originally posted by SoulAsylum in this picture i shot yesterday, i put the focus on the second tower ot this bridge, which i think it's enough to guarantee the sharpness. but which turns out not very sharp as i tought to be. Soul: the image is not posted (nor a link) so there is nothing to look at to see what the problem was. And since you are aware of hyperfocal distance. generally, this is the way to go, just remember to pay attention to the f numbers when "guestimating" (guessing and estimating) the HFD. Not all lenses provide this information though, and the use of Depth of Field preview can be very useful, if your camera has this. As SpecialK stated, about a third of the way into the depth of the image is a good "rule of thumb" (general rule) to use when picking a point of focus. Generally speaking, the relationship is DoF extends one third in front of your point of focus and 2 thirds , or more, beyond. However the further you stop down, to the high f numbers, the more the depth of field extends beyond your point of focus toward or to infinity. Regards,