Nikon Lenses and Hard Infinity Stop
Jun 4, 2019 17:43:43 #
SteveR wrote:
Back in my film days, I was taught when focusing at infinity to go to the infinity stop and back off just a tad. It seems to have worked then, I think it would work now. For the life of me, it was so long ago I can't remember the technical reason why, but there was one.
What you're describing is a "quick and dirty" way to employ the "hyperfocal distance" focusing method. Long before autofocus, manual focus lenses used to have distance and DOF markings for various apertures (and focal lengths in the case of zooms). You could set your lens using these markings to get in-focus images for a specific range of distance. Using the hyperfocal distance method you could get everything from, let's say, 10 feet to infinity in focus at a specific aperture once you set your lens that way. No need to even look through the viewfinder except of course for composition.
Jun 4, 2019 21:26:55 #
Does that mean the focus is electronic? My Canon spins forever because it's not physically geared to the focus ring. The nice thing about that is you can set the sensitivity in the camera menu.
Jun 4, 2019 21:28:45 #
bleirer wrote:
Does that mean the focus is electronic? My Canon spins forever because it's not physically geared to the focus ring. The nice thing about that is you can set the sensitivity in the camera menu.
No the Nikon AF-S is not focus by wire. It does move the lens element without power and not needed to mount on the camera. It's mechanical.
Jun 5, 2019 05:34:33 #
bleirer wrote:
Does that mean the focus is electronic? My Canon spins forever because it's not physically geared to the focus ring. The nice thing about that is you can set the sensitivity in the camera menu.
Older telephoto lenses regardless of manufacturer did not have an infinity stopp and allowed to go beyond infinity to a hard stop because as climate changed the lens changed and the location of infinity changed.
STM are all by wire and requite power to focus manually.
Jun 5, 2019 07:34:42 #
I'm not sure if this is the primary or secondary reason but it is actually it is good that the lens can go past infinity a bit. That extra play allows for AF Fine Tune adjustments which could otherwise prevent AF from achieving focus at infinity.
Jun 5, 2019 08:10:12 #
cactuspic
Loc: Dallas, TX
As I was taught, camera barrel expand and contract ever so slightly as they move between hot and cold weather. The engineers there gave a little room to accommodate the expansion and contraction. One way to test your camera to find infinity focus is to mount your camera on a tripod and manually focus on a very distant subject using a magnified live view setting.
Jun 5, 2019 08:12:48 #
One reason I like my AI manual lenses is that I know I can ram it to infinity any time I need it, and know it won't "over-infinity" and be out of focus. All these new-fangled AF lenses can't trust 'em for infinity being infinity...
Jun 5, 2019 09:22:34 #
"Didn't know there was a hard infinity stop on any lens."
In total agreement.
In total agreement.
Jun 5, 2019 12:32:47 #
Jun 5, 2019 12:49:16 #
bleirer wrote:
So what do you lose if you dial past infinity?
Sometimes you need to focus to infinity before the subject is there for you to focus on. Firework is one example. So if the lens stop turning at infinity you can easily set it to infinity.
Jun 5, 2019 13:25:46 #
BebuLamar wrote:
Sometimes you need to focus to infinity before the subject is there for you to focus on. Firework is one example. So if the lens stop turning at infinity you can easily set it to infinity.
So focusing past infinity would be similar to front focusing, in that the light hitting the sensor starts to diverge past the focal point?
Jun 5, 2019 13:44:43 #
bleirer wrote:
So focusing past infinity would be similar to front focusing, in that the light hitting the sensor starts to diverge past the focal point?
The image would be focused in front of the sensor yes.
Jun 5, 2019 15:21:13 #
There was a day when ALL lenses had a hard stop for infinity. I remember the confusion when, in the seventies, someone came out with a lens that focused "past infinity" to allow for more accurate focus at infinity when it was affected by high or low temps. Now, a lotof lenses a re fly by wire, so a hard stop isn't available because there's no direct mechanical connection between the lens mechanism and the focus ring.
Honestly, how critical is focus at infinity?
Honestly, how critical is focus at infinity?
Jun 5, 2019 16:21:35 #
Bill P wrote:
Honestly, how critical is focus at infinity?
Honestly, how critical is focus at infinity?
For those doing stars and Milky Way shots it’s a pretty big deal.
Jun 5, 2019 19:02:09 #
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