# Focus indicator dot with non AF-S lenses on d3100



## squirrels (Jan 28, 2013)

I'm using manual focus on a lens that won't autofocus on my d3100. I select my single focus point as if I were using autofocus. I focus as best I can and look for the little green light in the lower right corner to confirm that the camera also thinks I'm in focus. Am I just kidding myself with the little green dot or is this right?

C


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## tagan (Jan 28, 2013)

Yeah, you can look for the little green dot when manual focusing.  It will usually let you know when you have correct focus.


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## squirrels (Jan 28, 2013)

Thanks! I thought it should work that way, but that doesn't always make it so.

C


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## cgipson1 (Jan 28, 2013)

That should work fine for you, squirrels.....


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## KmH (Jan 28, 2013)

As an alternative, you can use Rangefinder mode. Page 144 of your D3100 users manual (the PDF file on the software disc).

The manual focus lens has to be a CPU lens with a D designation meaning the lens sends _*d*_istance info to the camera., like AF 50 mm f/1.8_*D*_&#8203;


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## squirrels (Jan 28, 2013)

Sweet. I will check that out. I'm obviously due up for another read through of the manual!

C


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## squirrels (Jan 28, 2013)

Thanks Charlie! Oh my goodness you guys! Rangefinder mode is just way too much fun.:smileys:


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## jrizal (Jan 28, 2013)

In case you have not noticed, rangefinder mode will not function in manual mode and only in aperture or shutter priority modes. Nonetheless, it is much easier to focus if it's on.


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## amolitor (Jan 28, 2013)

I spend a lot of my life flipping between Manual and Av mode. The rangefinder works in Av, but the shutter won't release because the camera doesn't think there's a lens and anyway it can't meter. The shutter WILL release in manual.


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## squirrels (Jan 28, 2013)

Yep. That's too bad about manual mode.  I wish viewfinder had one of those cool split prism things my MILs old school film nikon camera has. Focusing on that bad boy was a piece of cake.


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## squirrels (Jan 28, 2013)

Wait, so you have a "D" lens that works with the rangefinder but won't fire in anything but manual mode?


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## amolitor (Jan 28, 2013)

Oh, no, sorry. I have a handful of AIS lenses. The camera actually insists that "No Lens Is Attached" with 'em.


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## squirrels (Jan 28, 2013)

That is good to know! Thanks!


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## snowbear (Jan 28, 2013)

squirrels said:


> Yep. That's too bad about manual mode.  I wish viewfinder had one of those cool split prism things my MILs old school film nikon camera has. Focusing on that bad boy was a piece of cake.


You mean one of these?
Nikon D3100 Focusing Screen - KatzEye Optics


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