Can't get the hang of getting depth of field right on D40

[sharmi]

hi there folks

I really need to understand how to get depth of field right on my D40. My kit lens is 18-55 mm. I have tried using the dial, while on A / M modes, but I havent been able to get the pictures right.

I cant get the object sharp, instead what happens is that the background becomes sharp, and vice versa!

PS: Also, will getting a 18-200 macro/telephoto lens help in getting it right.

Please help!

[Shadowman]

hi there folks

I really need to understand how to get depth of field right on my D40. My kit lens is 18-55 mm. I have tried using the dial, while on A / M modes, but I havent been able to get the pictures right.

I cant get the object sharp, instead what happens is that the background becomes sharp, and vice versa!

PS: Also, will getting a 18-200 macro/telephoto lens help in getting it right.

Please help!

This should help.

https://www.cambridgeincolour.com/tu...h-of-field.htm

[Wirefox]

Sharmi

Also try this thread. In post 9 of that thread I used my own 18-55 to demonstrate what can be done. You will not get a brilliant focus blur with that lens but you can get it. Buying an 18-200 may not help unless it is a faster lens -f/4 or wider along the range of the zoom (Idealy f/2.8). If you are really into getting that blur a cheap 50mm prime may be a solution but obviously if you are looking for more range than your kit lens then there is going to be a compromise unless you have the cash to throw at a fast zoom. My cheapo solution was to buy an old Canon 70-210mm constant f/4 lens. It is EF so fully compatible with the cameras electronics (auto focus and aperture selection work fine) I am guessing there will be a similar solution for Nikon. I is not ideal but you are paying a 1/8th of the cost of the modern equivalent and the lens is by no means 8 times inferior - in fact in good light you would be hard pressed to tell the difference.

It may be worth posting some of your attempts here. It sounds as if you may be experiencing some problems with your focusing technique

[MajaMolly]

Thank you for sharing the link, Steve - very helpful.

[tbob]

Check the focal point setting in the autofocus menu to see if you might have one focal point selected and the camera is focusing on a background object rather than the subject. If the focal point is central and the subject is off to one side of the image the camera will focus on whatever is in the focal point not the subject you desire.

[tbob]

I forgot to add this. I can not remember if the D40 allows you to move the focal point around on the view finder, but this may also be something to check. If the focal point is off to one side; again the focus will be on whatever is in the focus point square.

[Dave Humphries]

hi there folks

I really need to understand how to get depth of field right on my D40. My kit lens is 18-55 mm. I have tried using the dial, while on A / M modes, but I havent been able to get the pictures right.

I cant get the object sharp, instead what happens is that the background becomes sharp, and vice versa!

PS: Also, will getting a 18-200 macro/telephoto lens help in getting it right.

Please help!

Hi Sharmi,

Welcome to the CiC forums from me.

As you're obviously new to all this, I want to clarify a few things before we all make assumptions and possibly give advice that might be even more confusing.

I will assume we are talking about a Nikon D40? I have a Nikon D5000, so I'll assume it is similar and talk you through how to check, with my apologies if this is too simplified. Do this in daylight and outside.

You need the switch on the lens barrel to stay in the M/A position, this allows the camera to Auto-Focus.

Turning to the camera, set the camera to aperture priority; "A" on the knob on top plate.

Use the control wheel to set the aperture to f/5.6, so you will be able to see the difference on a computer monitor (it is going to be tricky to see on the LCD).

Set the zoom to 55mm, aim the camera at something about 3 feet/1m away, but have a more distant object in view too.

Now try focusing (by half depressing the shutter button and waiting a second), then take a picture.

Now aim the camera at the distant object, at least 10 feet/3m away, focus, and take another picture.

Download and view both on your computer and verify that the correct things are sharper in each picture.

Post them here if you like.
I have assumed that the iso will be reasonable and exposure will take care of itself.
If you don't get the expected results, we can start delving into menu settings for Auto-Focus options, etc.

Cheers,

[Wendy Stanford]

Thanks for that link Steve, great explaination