35mm focus help

deanos · Sep 17, 2014

Hi

Newbie here.

I own a nikon d5300 and have purchased a 35mm f 1.8 for the holiday that I'm currently on. I have a good basic knowledge of my camera but I'm having problems understanding how to get the best out of my new lens in order to maximise focus against the bokeh

My example being: a woman holding aloft an umbrella. The blur is great but the umbrella is in focus and the woman is not.

Same as a flower, the leaves closer to me are in focus but the rest of the plant is not.

Please help as it's ruining my holiday photos.

Plus is there anyway on any sort of program that I can sharpen theses sort of images to get the required affect ?

Thanks

tirediron · Sep 17, 2014

It sounds like you're shooting with the lens wide or nearly wide open (at maximum aperture). This will result in a very shallow depth of field or amount of the scene that's in focus. To get more in focus, use a smaller aperture (larger f #). Read more here.

astroNikon · Sep 17, 2014

^^ as mentioned above
You need to learn more about what the aperture setting it.
It's not ONLY about letting in more light
but also Depth of Field .....

So you need to test and learn about it
Go find a long fence - a standard wire fence
Get next to it about a 45 degree angle.
set your aperture to f/1.8

use a Single Focus Point focusing - learn the different focusing points on your camera.
Learn each one and how to use it because your camera apparently liked the umbrella and focused on it. (with single focus point then aim it at her eye, don't let the camera decide for you)

focus on one point in the fence - such as add a ribbon or something to that point for distinction.

Then take shots at f/1.8, f/2.8, f.4, f5.6, f8, f/11, f/22 or anywhere you heart desires

First look at the smallest and largest aperture .. such as f/1.8 versus f/22
Notice the difference in what is in focus.

Then look at f/1.8 vs f/11
then f/1.8 vs f/4
f/1.8 vs f/2.8

That is Depth Of Field
The depth of what is in focus based on the aperture.
Now think of someone standing there and the "depth" of that person from a focus point.

If the camera focused on an umbrella then basically, let's say, anything more then 1/2 inch either direction will be out of focus. If you focused on her eye, then maybe only her outer nose and ears would be out of focus. And a aperture of f/5.6 would probably be needed.

If you want something in focus, you have to select the correct DOF.
Then you can add the Formula for distance to the subject in relation to DOF
--> A Flexible Depth of Field Calculator

and if you want a certain background OOF/aperture then you need to be at a certain distance
or just adjust your aperture for DOF and get the background bokeh that is the result of it.

Just don't use f/1.8 because you lens can do it.

I went bonkers with my 50mm/1.8 doing alot of stuff in f/1.8 until I did that fence test and learned alot. When I did self portraits I did f/2.8 because I could. a mentor of mine kept telling me basically why becz of DOF ... why? because I could LOL Now I know better. There's give and take to everything and you have to "Get the Shot" right the first time which is the most important. You can always take multiple shots and vary the aperture when someone is standing there .. I've done that alot until I started understand more about distance/DOF calculations.

deanos · Sep 17, 2014

tirediron said:
It sounds like you're shooting with the lens wide or nearly wide open (at maximum aperture). This will result in a very shallow depth of field or amount of the scene that's in focus. To get more in focus, use a smaller aperture (larger f #). Read more here.

Hi there. Thanks for the reply. I've been using 1.8 for the above mentioned photos. I've just taken a photo of my camera batter charger and I cannot get it all in focus. Either the plugs or the nikon sticker below will be in focus not the whole plug.

astroNikon · Sep 17, 2014

The lens has a MInimum Focus distance.
If it cannot focus then you are probably too close to the object

deanos · Sep 17, 2014

astroNikon said:
^^ as mentioned above
You need to learn more about what the aperture setting it.
It's not ONLY about letting in more light
but also Depth of Field .....

So you need to test and learn about it
Go find a long fence - a standard wire fence
Get next to it about a 45 degree angle.
set your aperture to f/1.8

use a Single Focus Point focusing - learn the different focusing points on your camera.
Learn each one and how to use it because your camera apparently liked the umbrella and focused on it. (with single focus point then aim it at her eye, don't let the camera decide for you)

focus on one point in the fence - such as add a ribbon or something to that point for distinction.

Then take shots at f/1.8, f/2.8, f.4, f5.6, f8, f/11, f/22 or anywhere you heart desires

First look at the smallest and largest aperture .. such as f/1.8 versus f/22
Notice the difference in what is in focus.

Then look at f/1.8 vs f/11
then f/1.8 vs f/4
f/1.8 vs f/2.8

That is Depth Of Field
The depth of what is in focus based on the aperture.
Now think of someone standing there and the "depth" of that person from a focus point.

If the camera focused on an umbrella then basically, let's say, anything more then 1/2 inch either direction will be out of focus. If you focused on her eye, then maybe only her outer nose and ears would be out of focus. And a aperture of f/5.6 would probably be needed.

If you want something in focus, you have to select the correct DOF.
Then you can add the Formula for distance to the subject in relation to DOF
--> A Flexible Depth of Field Calculator

and if you want a certain background OOF/aperture then you need to be at a certain distance
or just adjust your aperture for DOF and get the background bokeh that is the result of it.

Just don't use f/1.8 because you lens can do it.

I went bonkers with my 50mm/1.8 doing alot of stuff in f/1.8 until I did that fence test and learned alot. When I did self portraits I did f/2.8 because I could. a mentor of mine kept telling me basically why becz of DOF ... why? because I could LOL Now I know better. There's give and take to everything and you have to "Get the Shot" right the first time which is the most important. You can always take multiple shots and vary the aperture when someone is standing there .. I've done that alot until I started understand more about distance/DOF calculations.

Thank you that makes a lot more sense to me now

astroNikon · Sep 17, 2014

Nikone 35mm / 1.8 DX lens
Closest focusing distance. 0.3 m/0.98 ft.

astroNikon · Sep 17, 2014

deanos said:
Hi there. Thanks for the reply. I've been using 1.8 for the above mentioned photos. I've just taken a photo of my camera batter charger and I cannot get it all in focus. Either the plugs or the nikon sticker below will be in focus not the whole plug.

I misread it
try the shot again but use f/5.6 and see the difference
then try it with f2.8
and f/11

the larger the aperture number such as f/11 the more distance from the focus spot will be in-focus.
the smaller the aperture number such as f/1.8 the less distance from the focus spot will be in-focus.

deanos · Sep 17, 2014

astroNikon said:
I misread it
try the shot again but use f/5.6 and see the difference
then try it with f2.8
and f/11

the larger the aperture number such as f/11 the more distance from the focus spot will be in-focus.
the smaller the aperture number such as f/1.8 the less distance from the focus spot will be in-focus.

Thanks. Just tried it again and still no joy. Shutter speed becomes really slow so I increased the ISO. Is that correct ?

I will keep playing with it. I suppose bringing it on holiday was not the best option lol

I'll stick to my 18-55 until I can go home and practice.

Thanks again

deanos · Sep 17, 2014

Just one last thing. When you say focus point what exactly do you mean ? For instance the whole of the battery charger that's within the lined area through my viewfinder ? Silly question I know. I have done a shirt DSLR course but I'm new to this !

tirediron · Sep 17, 2014

Yes, either increase ISO or add more light (flash, reflector). I would suggest going through the whole series of tutorials here; it will give you a good grounding in the basics.

deanos · Sep 17, 2014

tirediron said:
Yes, either increase ISO or add more light (flash, reflector). I would suggest going through the whole series of tutorials here; it will give you a good grounding in the basics.

Thank you I will