Perfecting "blurry background" images

[im1dermike]

I recently wanted to get into photography, mainly to take pictures of my 3 year old daughter and the baby we're expecting in March. I did some research and ended up purchasing a Nikon D3400 as it seemed like a great camera for a beginner. I've watched some photography tutorial videos to learn the basics. I'm currently trying to fully understand "blurry background" pictures and had some questions.

I understand depth of field and aperture at a basic level. I have typically been shooting in aperture priority mode on my D3400 which I'm using the stock NIKKOR 18-55mm f/3.5-5.6G lens. I've found that the only times I truly have success with getting a "blurry background" is when I'm 3-4' from the image and have the aperture set at the lowest setting (4-5). Obviously only being able to take blurry background images when the image is very close (and necessarily small) has its limitations. I'm wondering how I can take pictures with the minimal depth of field where the background and foreground are blurry when the subject is 10' or so away.

Another question I have is the impact of metering on aperture priority pictures. There are three metering options on the D3400: matrix (default), center-weighted, and spot. It seems like spot metering would be the best choice for "blurry background" images since you want to focus on the subject within the depth of field. Is this correct?

Thanks!
Mike

 

[Braineack]

metering has nothing to do with optical rendering.

 

[weepete]

It's a lot easier at longer focal lengths, like 200mm. Subject to background distance is one of the main things, basically the further away from the background the subject is the more blur you will have in the shot, so if you are careful about you locations you can get some good blur even at middling apertures

 

[Designer]

This thread has a similar question:

Depth of field calcuations with a D500 and 24-70mm

 

[photo1x1.com]

We currently have another similar thread running - I won´t link to it because there was a lot of discussion about technical things going on that may confuse you.
However, here is part of the text I posted there, including a few add-ons, I hope it helps:

How blurry your background is going to get depends on a few factors:

• Maximum aperture of your lens (the lower the number the better). Prime lenses have bigger maximum apertures (lower numbers) that zoom lenses
  
• Focal length: the longer the better (like wepeete wrote above)
  
• Distance background - subject: the further the better
• Distance camera - subject: the closer the better
• Sensor size of your camera - the bigger the better

 

[im1dermike]

It's a lot easier at longer focal lengths, like 200mm.

I have a 75-300mm telephoto lens which should capture the 200mm focal length you spoke of. I was testing earlier and it didn't seem like the 10' was possible zoomed all the way out with that lens.

 

[vintagesnaps]

Kit lenses that come with cameras often aren't the sharpest or best lenses. With that aperture range you can only open the lens to f3.5; other lenses may have larger apertures up to f2 or 1.8, 1.4, etc. depending on the manufacturer. At some point you might want to sell/trade in the lens for a sharper prime lens or a zoom with larger aperture options.

But still you could get some blurry out of focus backgrounds. I'd suggest when you'll be wanting to take pictures, maybe while the baby is napping put down a blanket and see how the background looks. Decide if that would look good or if you should move the blanket, or move yourself and change your vantage point (which could change the perspective), or both, and see what you think will look good.

Even if you blur the background if there are lines and shapes and brighter and darker areas they may show up as blurry blobs that may not look so good. You could experiment and maybe take some test shots to see what it will look like. And with an active 3 year old, you may want to set up first before you get the two of them into place. Have fun!

 

[Designer]

.. when the subject is 10' or so away.

..it didn't seem like the 10' was possible..

Are you trying to hold to 10' for some reason?

With a 300mm or even a 200mm, I don't think you can get a person's head and shoulders in the frame in only 10' of space.

 

[im1dermike]

.. when the subject is 10' or so away.

..it didn't seem like the 10' was possible..

Are you trying to hold to 10' for some reason?

With a 300mm or even a 200mm, I don't think you can get a person's head and shoulders in the frame in only 10' of space.

That just seems like a common scenario for me and one that is posing a challenge with my current lenses.