16X Manual Lens Questions

Dean Orewiler · February 24th, 2006, 08:05 AM

From what I understand, you would get less depth of field or the "illusion of sharpness" with the 20x than the 16x because the 20x is a longer lens (now, this is under the assumption you have both lenses zooming out to the most powerful end and your camera and subject have not moved and you have the same framing and are using the same F-stop. Remember, all depth of field is "apparent sharpness" - The only true sharpness is your FOCAL POINT - and this is the true focus on what you are actually focusing upon - eyes, usually on a person - so depth of field or apparent focus will be sharper or less sharp depending on what F-stop you are using. If you use F 22 you will have MORE depth of field in front and behind the subject. If you use F 1.6, you will have LESS depth of field in front and behind your FOCAL POINT or whatever you are focusing upon. I teach a college class in digital and film still photography...and pretty much the same goes for digital photography with lenses. BUY the 16x - MANUAL FOCUS lens and you will be happy about the control you have over focus issues.

Tony Davies-Patrick · February 24th, 2006, 10:16 AM

"....From what I understand, you would get less depth of field or the "illusion of sharpness" with the 20x than the 16x because the 16x is a longer lens..."

No, the 20X is a longer lens than the 16X.

Dean Orewiler · February 24th, 2006, 10:08 PM

correct....the longer the magnification of a lens, the LESS the depth of field will be. Hence the reason the guys from SI shoot with long lenses with Large apertures so they can "blow" the background out of focus. Also your camera to subject has a lot to do with less DOF, too....

1. Length of lens
2. Camera to subject
3. F-stop

all of these affect depth of field

February 24th, 2006, 08:05 AM	#91
Dean Orewiler Regular Crew Join Date: Jan 2006 Posts: 186	DEPTH OF FIELD / FOCAL POINT issues From what I understand, you would get less depth of field or the "illusion of sharpness" with the 20x than the 16x because the 20x is a longer lens (now, this is under the assumption you have both lenses zooming out to the most powerful end and your camera and subject have not moved and you have the same framing and are using the same F-stop. Remember, all depth of field is "apparent sharpness" - The only true sharpness is your FOCAL POINT - and this is the true focus on what you are actually focusing upon - eyes, usually on a person - so depth of field or apparent focus will be sharper or less sharp depending on what F-stop you are using. If you use F 22 you will have MORE depth of field in front and behind the subject. If you use F 1.6, you will have LESS depth of field in front and behind your FOCAL POINT or whatever you are focusing upon. I teach a college class in digital and film still photography...and pretty much the same goes for digital photography with lenses. BUY the 16x - MANUAL FOCUS lens and you will be happy about the control you have over focus issues. Last edited by Dean Orewiler; February 24th, 2006 at 10:06 PM.

February 24th, 2006, 10:16 AM	#92
Tony Davies-Patrick Trustee Join Date: Feb 2005 Location: Worldwide Posts: 1,589	"....From what I understand, you would get less depth of field or the "illusion of sharpness" with the 20x than the 16x because the 16x is a longer lens..." No, the 20X is a longer lens than the 16X. __________________ www.WILDCARP.com www.NIKON.me.uk

February 24th, 2006, 10:08 PM	#93
Dean Orewiler Regular Crew Join Date: Jan 2006 Posts: 186	correct....the longer the magnification of a lens, the LESS the depth of field will be. Hence the reason the guys from SI shoot with long lenses with Large apertures so they can "blow" the background out of focus. Also your camera to subject has a lot to do with less DOF, too.... 1. Length of lens 2. Camera to subject 3. F-stop all of these affect depth of field