18-140 lens and infinity?

tiCreativeMedia

Hi,
I just got my 7100 today. I see that the lens that ships with it (18-140) does not have a setting for infinity. Do I need a different lens, or is there a way to set that to infinity?

thanks!
Dave

Photobug

Don't worry about it. For years Nikon has let their lens focus past infinity. When I looked at the new 18-140 I got to admit I did not look for the infinity mark. One of the tech geeks will reply with why they do this. I think it related to temperature and altitude but I could be wrong.

tiCreativeMedia

so, should the lens be all the way zoomed or not zoomed to make it infinity?

thanks-
Dave

DaveO

It shouldn't make any difference if it is zoomed out or in. Turn the AF off and manually focus until a distant object is in focus. The depth of field should be more than enough to cover the distance. If it makes you feel better put a dot of white White Out at that point as a reference. There are also magic markers in silver color that you could use to mark this position.

tiCreativeMedia

ok... LOTS to learn with this new camera. VERY different from my Olympus E-3, but the first shots are much nicer.

THANKS!!

tc88

In general, lens has small headroom past infinity to allow for adjustments. So don't turn AF all the way to the end. Rather, try to use AF or your own eyes to tell whether infinity is in focus or not.

heartyfisher

I think most if not all the nikkor AFS lenses don't have infinity markings.

Some techs say its to do with temperature causing differences in the lenghts of the lense barrels and lense elements. I myself belief that its that they have provided the buffer so that manufacturing tolerances can be relaxed a bit. Both of these is of course possible only because of the excellent electronics and smarts of the AFS system that allow for a more dynamic situation based Af adjustment.

spraynpray

I thought the adjustment past infinity was because of the need for the auto-focus system needing to 'dither' past in focus to out of focus and back to focus - in other words, it doesn't know it has achieved focus until it has gone past it.

PB_PM

A hard stop at infinity or the minimum focusing distance would not be good for mechanical parts, the focus drive needs space to slow down, and reverse direction if needed. Thus leeway is given.

spraynpray

I think the AF system of lenses incorporates some form of absolute encoding which enables it to know exactly where it is at any time so it would know it is approaching end of travel and stop without damage. A dithering action is common in electronic systems (such as satellite dishes on boats) that are searching for best position.

JakesGT

If it doesn't seem to focus at infinity, I would check the diopter

DaveyJ

How is the 18-140 Nikkor quality wise compared to the other Nikkor zooms??

heartyfisher

@Daveyj which lenses in particular are you thinking of .. I had a thread recently which compared the 18-140 vs the 18-200..

DaveyJ

@Heartyfisher: I will try to find your 18-140 vs 18-200VR. I have the second lens and MOST of the other 18-whatevers. Of course DXO Mark just posted a review of the 18-140 and they thought it was pretty good.

kenadams

Lenses that go *beyond* infinity... sounds like they may even go to 11... :-D

tiCreativeMedia

well, I finally had a chance to try out my camera on the moon, and it came out like I expected, and didn't want. Couldn't get that infinity focus, and it's just a blotch. I tried stepping down the shutter speed a ton and not matter what it was just a dot and not the moon, so I am wondering if this is because I don't have the infinity focus?

heartyfisher

No that blotch has nothing to do with infinity focus :-)

Consider this .. the moon is as bright as the stones you see at mid day.. ie Very bright . so the reason for the blotch is that its totally blown(ie over-exposed by 4-5 ev maybe more) and your sensor is bleeding light to the other pixels. That is why some people still use film for night shots like this.

Just noticed your shutter and aperture setting. You are about 12 stops too overexposed for the moon :-)

tiCreativeMedia

yep.. you got a point there, but I also tried doing a second shot with way less than a second shutter speed, and it still just looked like a dot-no texture in the moon.

If it's clear tonight, I'm going to try again, with even higher shutter speeds on the moon. Hopefully I can get that, then composite the 2

heartyfisher

no you need about 1/250 and F11 to photograph the moon (just like shooting at a mid day scene ).. do a search on how to photograph the moon :-)

heartyfisher

http://forum.nikonrumors.com/discussion/856/the-moon/p1

Raven

What a fab forum. Just got my NKD7100 in December/2013 with the 18-140lens. A step up from my NKP7000. Its a great do everything lens, and I also purchased the NK50mm and NK70-300mm. Still learning here... but so far I am totally impressed.

Shooting the moon is one of the reasons I upped the ante and bought this camera (yes... should have went all the way to FULL FRAME, but I am starting from scratch with lens and gear and venturing into DSLR. Plus... bow head in shame... budget!).

Thank you @heartyfisher for the kind comments above. Cant stand pedantic pretend know-it-alls who troll with negative comments for newbies. They SUCK! And the link you provided, is great. Cheers!

@tiCreativeMedia... same boat buddy. Learning the camera and how to shoot the moon. Continue to post your successes, or fails... learning from the trials and tribulations of others is how we all get better.

Cheers, Y'all... and thank you!

Pistnbroke

Its got AF why would you want to turn anything ??? Better to spend your time on adjusting the back focus ..both of mine are +12.....which in simple terms means its focusing 12mm away from the point you focused on.