Depth of field

mariajosesalazar · Sep 25, 2012

Ok, so as you might already know due to the fact that I am posting on a "beginners thread" I would like to say that I am currently taking a Photography I class and our last assignment was based on depth of field, although I did not get quite the images I was hoping for, I would like to know what I can do about it, meaning should I upgrade my camera due to the fact that the one I own right now (Canon EOS T3), the aperture only lowers to 4.0 and the lens I am shooting with is a Canon 70-300mm. I have tried to mess with my cameras control keys and I still cannot get quite the image I am aiming for.

Attached is an image that was taken of me by a photographer. Something like that is what I am aiming for, although the easy way should be me asking her, I do not feel comfortable doing so.

Could someone please give me feedback.

-No rude comments, please and thank you.

Mariajose

480sparky · Sep 25, 2012

Are you asking about comments on the photo (which, I will assume, you don't have rights to post here, but that's another matter), or have depth-of-field / bokeh explained to you?

Overread · Sep 25, 2012

Show us a couple of the photos that you've taken and detail the settings that you've used and the mode for the shot as well. The more details you can give the better. If you don't remember the settings check the properties tab by right clicking on the photo - then go to the "details" tab and scroll down it should list the aperture, shutter speed and ISO used for the photo (make sure its the ones used for the shot and not the lenses profile ones).
The more info you can give on how you took a photo and the more we can give on where you might be going wrong.

Also it should be noted that we generally prefer users to link to photos that they don't specifically own the copyright/distribution rights of, rather than uploading them to the site or embedding them as an image. I'm not sure on the situation with the photo that you have had taken of you so it will depend on your specific arrangement/contract with the photographer on that score (if you don't know it/don't have a contract spelling things out now is a very good time to look into getting them).

mariajosesalazar · Sep 25, 2012

Indeed I have permission to post it on here, so that's cleared off.

Unfortunately I do not have the photo details though. On my camera though I was shooting with 1/500 shutter speed, 4.0 f/stop, and the ISO on 200 for an outdoor portrait, yet I still did not get the shot. I tried manually focusing to what I wanted to focus and still no luck.

Big Mike · Sep 25, 2012

Welcome to the forum.

It looks like you are trying to achive a very shallow DOF. You can do that with your camera, but the lens will be a limiting factor. The main control we have over the DOF is the lens aperture....and you lens, with a maximum of only F4 to F5.6 (depending on zoom) is not ideal for a shallow DOF. But that being said, if you use a longer zoom setting and/or get closer to your subject, you can get a shallower DOF (but maybe not as shallow as you're looking for).

To get a really shallow DOF, you will want a lens that has a larger maximum aperture. Zoom lenses will go as large as F2.8 but prime (non-zoom) lenses can easily be found with maximum apertures as large as F1.8, F1.4 or even F1.2.

Check out the Canon 50mm F1.8, it's just a little over $100 and can give you a very shallow DOF.

mariajosesalazar · Sep 25, 2012

@Big Mike thank you so much, that helps! I really appreciate it.

Overread · Sep 25, 2012

One other trick you can try is to set the aperture to f5.6 and the focal length to 300mm. Yes you've made the aperture smaller (remember bigger f number = smaller aperture hole) which increases the depth of field, but using the 300mm end means that you will be able to frame the photo from further away. As a result of the increase in distance between yourself and the subject the separation of subject and background will increase. Furthermore if you've got the background further away from your subject that too will increase the degree to which it is blurred.

mariajosesalazar · Sep 25, 2012

Thanks, appreciate it!

CheezyCheeto · Sep 26, 2012

For all intents and purposes, it is the lens that is restricting how wide of an aperture you can go - not the camera body.

Muchi3413 · Sep 27, 2012

i am having the same issue as maria. no matter what i do i can not achieve a difference in my depth of field. i have a kodak z990 it is not exactly a dslr. its i guess a step under a dslr? its what i have to start in my photography 1 class. im working on getting a dslr. please no rude comments about my camera. ive done exceptionally well with all my other asignments.

KmH · Sep 27, 2012

Image sensor size also affects DoF. The smaller the physical size of the image sensor, the deeper the DoF it produces.
Digital Camera Sensor Sizes: How it Influences Your Photography

Your Kodak z990 has the smallest consumer digital camera image sensor made - 1 / 2.33
http://upload.wikimedia.org/wikipedia/commons/9/9a/Sensor_sizes_overlaid_inside_-_updated.svg

Heitz · Sep 27, 2012

KmH said:
Image sensor size also affects DoF. The smaller the physical size of the image sensor, the deeper the DoF it produces.
Digital Camera Sensor Sizes: How it Influences Your Photography

Your Kodak z990 has the smallest consumer digital camera image sensor made - 1 / 2.33
http://upload.wikimedia.org/wikipedia/commons/9/9a/Sensor_sizes_overlaid_inside_-_updated.svg

Well technically it's not the sensor size proper but the fact that holding framing constant, you have to use longer focal length on FF, and that in turn affects dof... Right?

KmH · Sep 27, 2012

DoF doesn't change appreciably when subject scale is maintained in the frame with different focal length lenses. DOF2

MLeeK · Sep 27, 2012

Muchi3413 said:
i am having the same issue as maria. no matter what i do i can not achieve a difference in my depth of field. i have a kodak z990 it is not exactly a dslr. its i guess a step under a dslr? its what i have to start in my photography 1 class. im working on getting a dslr. please no rude comments about my camera. ive done exceptionally well with all my other asignments.

You are having trouble because of the size of your sensor. It is so small that it is very hard to achieve a shallow depth of field. Click on the links Keith gave and it will explain much more.
You would need to be VERY close to your subject and your background would need to be VERY distant. It's not totally impossible, but it's pretty hard to get a good shallow DOF with a bridge/point and shoot. It is the chief problem people who learn control on a bridge have when they upgrade to a DSLR. All of a sudden they have major focus issues that they don't understand.