Depth of Field Assignment

[lexcell]

OK, everyone, how about an assignment?
-Take your camera and ALL of your lenses and find a scene that has something in it from near to far so you have something to compare the DOF. In other words, you need a foreground, middle ground and background.
-Set up your tripods and attach your cameras.
-Then take each lens you own and shoot the scene cycling through all the aperture settings in one stop increments (2.8, 4.0, 5.6, 8.0, 11, 16, 22, etc).
-If you have zoom lenses do the same thing at both the widest focal length and again at the longest.
-Focus approx 1/3 into the scene. Do this with each of your lenses wide through tele.
-Download your images and compare the DOF in each image at the varying apertures and focal lengths.
-Shoot all images from the exact same location for this assignment so that one thing is constant.
I think you will find this to be very enlightening in how depth of field works.
Have a great weekend!

[nkeevers]

Laurie, thanks. Was planning on going to the park on the river this weekend with my dog (and husband too!) so I'll have to try this out. Great assignment and maybe it'll help me.:D

[GeoR]

Thanks Laurie for the Depth of Field assignment. Found the ideal field with a fence around it. Just hope the farmer don't mind me using a tranquilizer gun on his cows. :twisted::D GeoR

[nkeevers]

LOL on that one! I can just picture it now!:D

[nkeevers]

I'm always afraid to change lenses outside. How to I change them without having something blow into my camera?

[RobertSchuldenfrei]

I'm always afraid to change lenses outside. How to I change them without having something blow into my camera?
It is not perfect, but here is what I do:

1/ With a flat surface at hand take the cap off of the back end of the lens you are going to mount. Stand it up on the front lens cap.

2/ Point you camera down and remove the old lens. Stand it up on the front lens cap.

3/ Keeping the camera pointed down, mount the new lens.

4/ Cap the old lens.

Hope this helps,

Bob

[nkeevers]

Thanks. I usually point the camera down too but didn't know if anyone did anything different.

[lexcell]

I simply change lenses...
I point away from the wind and make sure that I have the lens I want to attach ready then I take the lens off the camera, and attach the new lens. I deal with lens caps after attaching the lens since I don't want to leave the camera exposed for any longer than I have to.

In te digital age, dust on the sensor is a fact of life. However, dust is not the only issue...every time you chagne lenses, regardless of inside or out, there are little metal/plastic shavings from the metal/plastic of the lens rubbing against the camera body that get into the mirror box and get on the sensor.

At some point you will have to clean your sensor. I have to clean my sensor almost nightly when I am out shooting all day, changing lenses, etc.

Here is an excellent tutorial for cleaning your sensor:
http://www.moosepeterson.com/techtips/cleanccd.html

It is important to have the correct tools for the job. Once you have done it a time or two, you lose the fear...honestly. :)

[nkeevers]

Laurie, thanks for the info and the website. I will definitely order that!

Now I won't worry if I change lenses. I've always heard stories from everyone about making sure it's in a bag or etc., etc. I alway point mine away from wind and down so I think I'm okay. I've cleaned mine once since I've had it. But I still have a small light dot at the top which I can't seem to see so maybe the kit will help!

[lexcell]

B&H also sells the Visible dust Products and if you are a member of NAPP, they have free three day shipping.
I don;t believe Moose mentions the sensor loupe in his tutorial...it came out later. It's a really cool loupe that has lights so you can actually "seee" the dust on your sensor. Well worth the cost.

[nkeevers]

Laurie, well, I went to the park today with my tripod and my lenses. I went through all the aps and looking at my pictures I don't see any changes!!:eek: Wonder what I did wrong. Maybe my spot wasn't 1/3 in; maybe I used 1/2, not sure! I went thru every aperature change but I don't see any DOF changes.

[lexcell]

Norma,
Can you post a couple of images? Say one at the widest aperture and another at the smallest? We can evaluate the situation and everyone can learn from this?

[nkeevers]

Yes, I'll post a few. And I had some other pictures where the sky was blue and in these, it's blown out.

I'll post shortly.

[nkeevers]

Okay here are 3 all at a focal length of 59mm (was I supposed to change that?)

f/6.3 shutter 1/400 ISO 200
http://www.pixentral.com/hosted/1tjfzZy9KywmRb8XpE7LbNjlYw0Ad4_thumb.jpg (http://www.pixentral.com/show.php?picture=1tjfzZy9KywmRb8XpE7LbNjlYw0Ad4)


And this one is f/25 shutter 1/25 ISO 200
http://www.pixentral.com/hosted/1QsPYWHxXEbnBXIGQYfbKrhhOuOqas0_thumb.jpg (http://www.pixentral.com/show.php?picture=1QsPYWHxXEbnBXIGQYfbKrhhOuOqas0)

Maybe I wasn't into the first 1/3 of the picture and more like focusing 1/2 into...that's why I didn't see any change.

Here's another 2 at 70mm

This is f/7.1 shutter 1/200.
http://www.pixentral.com/hosted/174vQYL8267Uy2jBOhFY0PErPuEyhh_thumb.jpg (http://www.pixentral.com/show.php?picture=174vQYL8267Uy2jBOhFY0PErPuEyhh)

This at f/25 shutter 1/8
http://www.pixentral.com/hosted/1DeJDVa9XeqXZ9BZtE0SopBbJ8BnzN1_thumb.jpg (http://www.pixentral.com/show.php?picture=1DeJDVa9XeqXZ9BZtE0SopBbJ8BnzN1)

[GaryK]

Hi Norma

The water didn't help, hard to tell what is focused and what is not.. and I think maybe you are right about where you focused.

In both examples though, the front scraggly tree is way sharper at f25.

[bayhli]

What I notice is that some of the shutter speeds are very low - would that not also be impacting the photos in terms of less sharpness due to slight camera shake?

[nkeevers]

I was focusing on the big tree but I think I was more than 1/3 into the picture. Gosh, I've done better on other days, and w/o the tripod. Guess I'll have to try again this weekend.

[lexcell]

Norma,
Good job on trying the assignment. The foreground tree should be sharper in the images with the smaller aperture (f25) than those at the sider aperture. Part of the issue here is that everything except the tree is basically at what the camera considers infinity so you won't see much of a difference in DOF except in the foreground tree.

Try again and make sure you have a foreground (something with detail that is close) middle ground (again with detail) and background (more detail) so you can see the change.

A tripod is a must for this assignment and you will have some slow shutter speeds at the smallest apertures.

Try this....fine a brick walkway or a fence or something that has detail that is leading away from you. Try the assignment again focusing approx 1/3 into the frame and cycle through the apertures again. This is a test for you to see the DOF change as you change apertures so that you have an ide of where to set your lens to achieve the amount of depth of field you desire.

[nkeevers]

Okay I'll try it again. Thanks for the suggestions.

[Elemobe]

Norma

Just wanted to thank you for posting your photos. I am watching and learning and your example was very helpful.

Really want to do this assignment, and will, just waiting until I get a tripod. I did try using a step ladder - but that really didn't work:eek: Gave the sheep in the field a laugh though:D

In the meantime, I am picking up pointers from your efforts.

Btw, the sheep surround our garden, I didn't go out for a walk with the step ladder, thought I should clarify that point;)

[nkeevers]

LOL! That's funny about the sheep! And the stepladder!!

I'm going to try again tomorrow in my front yard. See what happens. I'll post the pics.