Infinity question
Jan 14, 2019 12:31:28 #
RWR wrote:
When the image is in focus on the focusing screen, it will be in focus at the focal plane.
If you check "Quote Reply" as I did here we can see who each response is directed at.
True for Electronic Viewfinder AND Live View but not optical viewfinder.
Jan 14, 2019 13:02:34 #
RWR
Loc: La Mesa, CA
PHRubin wrote:
If you check "Quote Reply" as I did here we can see who each response is directed at.
True for Electronic Viewfinder AND Live View but not optical viewfinder.
True for Electronic Viewfinder AND Live View but not optical viewfinder.
My comment was directed at whoever should read it. And of course it’s a fact with optical viewfinders.
Jan 14, 2019 13:09:09 #
[quote=Gene51]Many internal focus lenses, zooms included, change the focal length as you zoom.
I should hope they would, otherwise they could not be regarded as 'ZOOM' lenses!!!!
Surely ALL zoom lenses ought to change the focal length as you zoom?
I should hope they would, otherwise they could not be regarded as 'ZOOM' lenses!!!!
Surely ALL zoom lenses ought to change the focal length as you zoom?
Jan 14, 2019 14:19:08 #
wdross
Loc: Castle Rock, Colorado
dyximan wrote:
I have a Nikon D 500 with the Nikkor 18 to 300 mm ... (show quote)
Most zooms have nodal points that change as one zooms. This make a it impossible to make a fixed focus scale that will be accurate through out the scale's use. The manufactures have figured most photographers will use the auto focus and, if necessary, manually adjust using the screen/viewfinder. They choose the scales figures where they will be mostly true. They are not expecting most photographers to actually use the scale. This is quite a change from pre auto focus days where the focus scales had to be somewhat accurate.
Jan 14, 2019 19:30:52 #
rfmaude41
Loc: Lancaster, Texas (DFW area)
PHRubin wrote:
If you check "Quote Reply" as I did here we can see who each response is directed at.
True for Electronic Viewfinder AND Live View but not optical viewfinder.
True for Electronic Viewfinder AND Live View but not optical viewfinder.
Read the last 1/2 of that sentence, please. VARIFOCAL means that the FOCAL POINTS CHANGE, eh ?
Jan 14, 2019 20:44:55 #
dyximan wrote:
I have a Nikon D 500 with the Nikkor 18 to 300 mm ... (show quote)
Infinity focus should be with the ring turned all the way to the stop -- not necessarily
the center of the infinity symbol.
Lenses are adjusted at the factory using a collimator. However, things can change.
Sometimes a lens will not focus all the way to finity, or sometimes it will focus
beyond infinity.
Beyond infinity can be worked around by putting a new infinity mark on the lens
ring with a bit of adhesive tape and a pen.
No parfocal zoom lens is perfect. There is always a tiny bit of defocus for some focal
settings. But it sounds like maybe your lens is worse than most.
A zoom lens is like a compact racing dump truck. It does a lot of different jobs, but....
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