NTP Challenge: Aperture and Depth of Field (DOF)

[stevo01]

Nice post shaggy, those two shots provide a good example of how depth of field (and specifically a narrow depth of field) can be used to draw attention to, or highlight, the subject of interest. In shot #1 the viewers eyes are drawn immediately to the lizard's eyes/head region, where as in shot #2 (with the greater depth of field) the photo is very "busy" and the viewer's eye isn't really drawn to one particular area of the photo, and the background and foreground/subject of the photo tend to merge into one.

[ricktas]

Good example of the difference that aperture settings can make to the result. At least now with an understanding of that, if you have a friend say they wanted a nice photo of themselves, you would know how to isolate them from the background and get a creative result. Which is the idea of this particular challenge.

[seastorm]

Good pics, shaggy!!

As Stevo says, the greater the DoF, the busier the pic seems to be, ie more distractions.

Can we have a new challenge now, Rick?

[David]

Had a question here but put it elsewhere because the genre Im thinking of is landcapes, not this type.

[shaggydog]

Thanks for the comments. I apologise for getting ahead of myself and will now crawl before I try and walk.

[seastorm]

Don't have to apologise, shaggy, sometimes it's a good way to learn

[EdenJane]

Since my trusty D100 has spent most of its life on P mode I decided to start learning a little more about its features & working through the challenges is a great place to start. I am doing an online course at the moment that I paid for but I am learning a lot more here form looking at other people photos & critiques & reading all the beginner info ( thanks Rick)
So as my DOF I was a little limited as I had my two kids & my nephew to watch so was somewhat housebound so I lined up their morning tea.
Because it was indoors & the light wasn't great & I don't like the built in flash I upped the iso to 800... so unfortunately they are somewhat grainy but I think they illustrated the DOF thing ok. In the wide aperture F3.5 the front pear only is in focus & this seem to bring all the attention onto it & blur out other distracting elements. The narrow aperture was at F20 & in this aside from the grainyness ( due to poor light, high iso) all elements are essentially in focus...including things like the kitchen wall & bar stools. This makes the picture more about all visible elements & less about the pear! I used a 60mm nikkor lens.

wide.jpg
narrow.jpg

[bigdazzler]

thats a spot on example of DOF using Aperture selection .. Well done Edenjane

Ill just touch on something else (seeing as this is the Aperture/DOF thread ill be brief)

Take a look at your exif and note what happened to your shutter speed when you stopped down to f20 .. much much slower right ?? 1/160th down to 1/6th. I mention it because its a good indication of how two elements of the exposure triangle work in conjunction with each other. But thats a discussion for another thread .. just thought it was a good example.

Well done ..

[EdenJane]

Thank you getting my head around the interactions between all these things is going to be my next task. I just noticed I had my exposure compensation on -0.7 from a previous session..oops..that might explain what they are somewhat on the dark side! I plan to do the SSspeed challenge next.

[Newbie79]

Hi all, This is the first NTP challenge that I have done and my first attempt at posting.

I have taken four photos which I am posting. All photos were taken on Av mode of my camera and so all i changed was the f value between each set of photos.

Image one was taken at f22 and is of the Bonsai in the white pot in the fore ground. What I notice is that virtually everything in the photo is in focus and that because of this the bonsai is lost in all the other plants surrounding it. Image 2 is taken at f 5.6 and the first thing I notice is that the Bonsai seems to stand out from everything else (even from all the other plants) because it seems to be the only thing in focus. I also notice that the further back in the photo you look the more out of focus it seems to be (The other bonsai is less out of focus than the black bin in the background)

Image 3 is taken at f 22 and image 4 at f3.5 The comments i made above also seem to be true of these two photos with the exception that the difference between how much the background in each photo is out of focus seems to be much more subtle. If someone can please tell me if I am right or not but from the reading i have done this is because there is such a small distance between the front of the photo and the back (the fence)??? Is this right?

I know the photos are not master pieces but I am hoping they illustrate what I was meant to learn from the Challenge?

Thanks heaps

Matt

[ricktas]

Good work Matt. Hope this taught you what the aperture does to your photo, and as you progress through the learning centre and the other challenges you will learn how to combine camera functions to achieve the desired result that you wanted.

What did you notice about the shutter speed as you changed the aperture?

[kiwi]

I hope you dont mind, but can I add a couple of hard learnt lessons that I have found

Before deciding what apperture to choose, look at the background and think about what effect on that background changing your apperture will have....eg if a person is standing next to a wall it really will not matter to how the wall will look in the picture if you shoot at f/8 or f/1.8 but you'll get a much sharper picture at F/8

So, dont shoot wide open just because you can.

[Newbie79]

Ricktas,

In answer to your question I noticed that the larger the aperture (smaller the f number) the quicker the shutter speed was. I am assuming this is because more light can get in at once the smaller the f number is.

I tried taking some more photos last night inside the house and noticed that the larger the aperture became the shutter needed to open for so long that it was impossible to hold the camera still long enough. I am assuming this again is a lighting issue?

A Question!

If I was taking a picture of object A and object B was behind this and then Object C was further behind again what would be the easiest way to work out how to keep both Object A and B in focus whilst having Object C out of focus. I guess i'm asking how can i quickly work out what my DOF will be before taking the photo so that I can keep the object I want in focus?

Thanks Matt

[ricktas]

Re your question, the easiest way (other than experimentation) is to use a Depth of Field calculator. You put in the camera, lens details, the distance to subject, etc, and it tells you the distance front to back that will be in focus.

A good online example is here: http://www.dofmaster.com/dofjs.html

[Newbie79]

Hi all,

Have been taking quite a few photos of different things practicing using Av mode and altering the DOF. Just thought I would share these with you all. Was amazed that i could control the DOF over such a small distance (from the front of my wedding ring to the back). One was taken at f 5.6 and the other at f22

Things are starting to make sense to me now. Thanks for your time.

Matt

[seastorm]

Great pics there Matt, definitely can see the difference between the different f/ numbers

[Amadeus]

Ok, just shot at the first thing I saw... nothing very creative here.

ISO left at 100, first shot is f/4 and second shot is f/22

f/4 brought the shutter speed to 1/100 (a lot faster) whereas f/22 brought the shutter speed to 1/6.

This caused the DOF to increase with f/22...

[etherial]

You got it! Now along with the shutter speed challenge you did, you can see how you can use these aspects to your advantage to achieve a certain effect when shooting subjects.

[Amadeus]

Cheers. Was thinking I'd go back to the road scene from shutter speed challenge and shoot there again but with the change in aperture settings for comparison's sakes - is this worthwhile?

[etherial]

If you go back and look at the photos from the road you will see the aperture was changing itself to suit the shutter speed. In Aperture priority mode your camera will select the best shutter speed to get the correct exposure and if shutter priority mode the camera will select the right aperture to get the correct exposure. Which ever selection you choose they will give the same result.

Try it at home, put you camera on Av select F8 and point it at something. Note the shutter speed it picks. Then flick it over to shutter priority and select the shutter speed you just noted. Point it at the same subject (with the same lighting) and it should be close to F8.

When out shooting subjects the trick is to think what your priority is, are you trying for shallow depth of field or freezing action etc...which will determine which mode you use.