Focusing with 50mm f/1.8

[lfoush]

I shoot with a Nikon d3100, and when shooting with my 50mm, I have to manually focus as automatic focusing is not possible. When shooting in A and S modes, I can tell when I am getting the sharpest focus on what I want to focus on. I simply move the dot to what I want to focus on, and then focus the lens according to the needle on the bottom of the viewfinder. When I shoot in manual however, the needle no longer tells me if I am achieving sharp focus, but tells me if the photo is overexposed like it normally does when shooting in automatic. Is there a way to tell if I am achieving the sharpest focus when shooting in manual other then just by eye sight and "guessing?" It is very frustrating as I shoot in this mode a lot and have to "guess" the sharpest focus. Sorry if this doesn't make much sense.

 

[Big Mike]

Look for the focus confirmation dot. It's a green dot that should appear in the bottom corner of the viewfinder, when you have achieved focus. It works in both auto & manual focus.

 

[tirediron]

I think you may be confusing the indicators in your viewfinder. If by the 'needle' you mean the strip of vertical bars that run along the bottom of your viewfinder, that is your exposure meter, and has NOTHING to do with focus. Your focus indication is a green dot that should be to the left of that. When you see the green dot appear, you know you have something in focus (assuming you're using the 50mm 1.8 D lens). As modern DSLRs were not meant for manually focusing, it is a bit of a challenge; the best way I have found is to very slowly focus the scene to the point where you think it's perfect and then go just a hair past that, and then, even more slowly back up. You should see the focus indicator illuminate. Check your manual for more information.

 

[jwbryson1]

I think you may be confusing the indicators in your viewfinder. If by the 'needle' you mean the strip of vertical bars that run along the bottom of your viewfinder, that is your exposure meter, and has NOTHING to do with focus. Your focus indication is a green dot that should be to the left of that.

^^^ This.

 

[Tailgunner]

I think you may be confusing the indicators in your viewfinder. If by the 'needle' you mean the strip of vertical bars that run along the bottom of your viewfinder, that is your exposure meter, and has NOTHING to do with focus. Your focus indication is a green dot that should be to the left of that. When you see the green dot appear, you know you have something in focus (assuming you're using the 50mm 1.8 D lens). As modern DSLRs were not meant for manually focusing, it is a bit of a challenge; the best way I have found is to very slowly focus the scene to the point where you think it's perfect and then go just a hair past that, and then, even more slowly back up. You should see the focus indicator illuminate. Check your manual for more information.

Agreed, you use the meter to adjust for exposure. I also own a D3100 w/50mm f1.8D and do the above mentioned method in order to focus when manually focusing all my glass.

 

[Big Mike]

I think you may be confusing the indicators in your viewfinder. If by the 'needle' you mean the strip of vertical bars that run along the bottom of your viewfinder, that is your exposure meter, and has NOTHING to do with focus. Your focus indication is a green dot that should be to the left of that. When you see the green dot appear, you know you have something in focus (assuming you're using the 50mm 1.8 D lens). As modern DSLRs were not meant for manually focusing, it is a bit of a challenge; the best way I have found is to very slowly focus the scene to the point where you think it's perfect and then go just a hair past that, and then, even more slowly back up. You should see the focus indicator illuminate. Check your manual for more information.

Actually, the D3100 can display a focus range indicator.

One feature that owners of older AF lenses will appreciate is the Nikon D3100's exposure meter scale can act as a manual focusing aid, indicating which direction the lens needs to be adjusted to achieve focus. The option for the scale to behave this way is selectable in the Setup menu. This "Rangefinder" function as Nikon calls it, is not available in manual exposure mode as the scale then indicates exposure regardless of the Setup menu setting.

 

[Big Mike]

So I guess the answer to the OPs question...is that you can't have the 'rangefinder' display while in manual mode.

 

[tirediron]

So I guess the answer to the OPs question...is that you can't have the 'rangefinder' display while in manual mode.

Cool! Learn something new every day! (But... I was sorta right!).

 

[jwbryson1]

Actually, the D3100 can display a focus range indicator.

:shock: Whoa. Cool....

 

[Tailgunner]

So I guess the answer to the OPs question...is that you can't have the 'rangefinder' display while in manual mode.

Exactly, the OP is shooting in manual, so it's like rangefinder doesn't exist and their viewing the exposure meter instead.

 

[Big Mike]

I've also seen some models where the exposure scale in the viewfinder (or maybe just on the rear LCD) acts a a level. Crazy Nikons

 

[tirediron]

I've also seen some models where the exposure scale in the viewfinder (or maybe just on the rear LCD) acts a a level. Crazy Nikons

The mid-level and up bodies have a built-in 'false horizon'. I looked at it once to see what it looked like... couldn't even tell you how to turn it on now!

 

[Big Mike]

The students in my classes have all the different models of Canon & Nikon...with a few other brands once in a while. I really can't keep up with all the bells & whistles.