Moving from Automatic - advice

I would like to learn to shoot with more creative control. I have been trying to find the best way to do this through online tutorials. The last one has me learning more about Aperture at the moment.

In an attempt to do this, I set my camera (canon eos 20d) on AV mode and tried photographing a few different "scenes".

First and indoor close up of one of my kids toys with some other stuff behind it (by about 12 inches) and the second a group of leaves or a flower outside.

SO - first I was testing whether I wanted to have the camera at no zoom at all and just move in as close as possible to the object - (does not give me clear pictures at all) vs taking steps back and zooming in (seems to give the best results). I have done a few tests turning the aperture all the way down, which seems to be f5.0 when I am zoomed in, and up to about f13 at various distances from my subject. What I am finding and what i am struggling with is this;

it seems, to get the look i want - clear front subject, very blurry background - my camera in AV mode needs to be set at f6.0 or just a tad higher. This seems contradictory to what I am reading my settings should be at to achieve that look. From what I read I would want an aperture of f2.0 or 2.8 (which I my camera does not do anyways).

Clearly, I tend to over analyize....I am focused on the wrong thing or am I just being dense?

Start here: http://www.dofmaster.c​om/dofjs.html If you enter your camera and focal lengths it will help you predict your depth of field. Depth of field is the area of acceptable focus. Just a few hints. The closer you are to the subject at a given aperture, the less DOF you get. Keep in mid that with the lens that you have, your ability to get shallow depth of field might be limited. Play with the simulator change variables to see the effect on the DOF.

I'm guessing from your post that you may not be aware that aperture is a property of the lens, not the camera itself. The reason why you're unable to set values like f/2.8 is because whatever lens you're using doesn't open that wide.

The blurriness of the backgroud is dependant on the aperture plus the distance between the background and your subject. If the background is very close, eg if you're shooting a subject right in front of a wall, then your background isn't going to be that out of focus, especially if the widest you can shoot is f/5.

I think to fully get to grips with aperture you really do need to get a lens that can open pretty wide. What lenses do you have?

Ok, I think it is sinking in.

To really experiment with aperture and DOF I want more distance between me and my subject, and then zoom in.

Onona - I believe it is a 250mm

Thank you for the replies - I am going to shoot some things

If you don't mind spending a bit of money, consider picking up a cheap 50mm f/1.8 lens. These lenses are pretty useful to have for portraits and whatnot, and since they open up pretty wide, they're a great way to experiment with aperture and depth of field. They don't offer the greatest pin sharp quality but they do offer good value for the price.

bran wrote in post #15004466
SO - first I was testing whether I wanted to have the camera at no zoom at all and just move in as close as possible to the object - (does not give me clear pictures at all) vs taking steps back and zooming in (seems to give the best results).

Did you find out why you weren't getting clear pictures in the first scenario? It is almost certainly due to you being too close - check your lens' minimum focusing distance.

Dan Marchant wrote in post #15005696
Did you find out why you weren't getting clear pictures in the first scenario? It is almost certainly due to you being too close - check your lens' minimum focusing distance.

I didn't. I did some more experient shots outside and no matter how far I am from the subject I am not getting a blurry background.

If I am reading my lens correctly it is a 18-250mm, I assume that is what the minimum is derived from.

which to be honest helps me little, since after I take the pictures I have no way to know how far from the subject I was or how zoomed in I was.....

This post is pretty much exactly where I am at with my experimenting with 'creative' photography. I was out over the weekend and was pretty dissatisfied with the DOF I was getting through the lenses that I have, mostly because I was using kit lenses. I am now researching my next steps.

I had just bought the 55-250 lens on friday, so I returned it to Best Buy. One of the things that was ticking me off was consistantly having to change lenses while out on this photo walk I was on. And I am seriously thinking of picking up a nifty fifty in order to have something with a wider aperture.

I'm learning... it's slowly kicking into this brain of mine...

I am trying to learn to use what have first.

Maybe what I really need to do is stop focusing on the sharp portrait type shot and just learn what else the aperture does

bran wrote in post #15006040
I am trying to learn to use what have first.

Maybe what I really need to do is stop focusing on the sharp portrait type shot and just learn what else the aperture does

So, you should see the numbers 3.5-5.6 on the end of your lens, after the 18-250. These all indicate various things about your lens:

18-250: These are the focal lengths that this lens cover, with the widest angle being 18mm and the narrowest angle being 250mm.

3.5-5.6: These are the maximum aperture values of this lens at each end of the focal range. At 18mm, you can open your aperture up to a maximum value of f/3.5, whereas, at 250mm you can only open it up to a maximum value of f/5.6. These apertures are going to severely limit your ability to get really blurred backgrounds without moving your subject WAY in front of those backgrounds.

The minimum focus distance of the lens is not derived from any of those numbers, it's just a function of the lens and should be called out in the user's manual somewhere. Since it's the 18-250, I believe that lens is a Sigma, correct? If so, that means your MFD is 13.9 inches; meaning that you cannot focus on anything that is closer to your camera than that. To avoid some of the problems that go with focusing at MFD, I'd make sure that you're at least 2ft away from whatever you're shooting while you figure the rest of this stuff out.

Also, do you understand the basics of aperture and understand what the aperture is and how the amount of light and your image are affected by larger/smaller apertures?

Snydremark wrote in post #15006141
So, you should see the numbers 3.5-5.6 on the end of your lens, after the 18-250. These all indicate various things about your lens:

18-250: These are the focal lengths that this lens cover, with the widest angle being 18mm and the narrowest angle being 250mm.

3.5-5.6: These are the maximum aperture values of this lens at each end of the focal range. At 18mm, you can open your aperture up to a maximum value of f/3.5, whereas, at 250mm you can only open it up to a maximum value of f/5.6. These apertures are going to severely limit your ability to get really blurred backgrounds without moving your subject WAY in front of those backgrounds.

Also, do you understand the basics of aperture and understand what the aperture is and how the amount of light and your image are affected by larger/smaller apertures?

the numbers after the 18-250 read as 1:3.5-6.3 so yes exactly your point.

I understand the basics of aperture being the amount of light that passes through the camera. The small the f-stop the less light, also the more shallow the DOF.

I am more of a kinetic learner so I just have to find the right "assignment" to help me learn aperture...I am trying.

See if this sheds some light on using different settings: Virtual Camera
http://www.photonhead.​com/simcam/

-=Photography Tips and Tutorials List=-

bran wrote in post #15006217
the numbers after the 18-250 read as 1:3.5-6.3 so yes exactly your point.

I understand the basics of aperture being the amount of light that passes through the camera. The small the f-stop the less light, also the more shallow the DOF.

I am more of a kinetic learner so I just have to find the right "assignment" to help me learn aperture...I am trying.

The primary point of this thread is controlling perspective in your images, but it should also give you some things to think about and try for yourself in regards to what you're playing with. I'd recommend reading through it.

Also, go check out DoFMaster's online DoF calculator: http://dofmaster.com/d​ofjs.html

You can plug in various combinations of focal length, aperture and distance to your subject to see what difference those things make in your depth of field. From there, you can set up a test subject and try those settings out for yourself.

Thanks for the information. I'll try it.

bran wrote in post #15005858
If I am reading my lens correctly it is a 18-250mm, I assume that is what the minimum is derived from.

which to be honest helps me little, since after I take the pictures I have no way to know how far from the subject I was or how zoomed in I was.....

No those numbers don't indicate the minimum focal distance. If Snydremark has correctly identified your lens then the minimum distance at which it can focus is 13.9 inches. So, in the example given in your first post, if you simply get "as close as you can" and this distance is less that 13.9 inches from your subject then your camera will be unable to focus and you will not get a clear shot.

However, this should be obvious before you take the shot as the view through the viewfinder wont be in focus and you camera should flash a warning to indicate that it has not managed to focus.

If you are further than 13.9 inches away and your subject is not clearly in focus then you are not focusing properly (or your lens is very badly calibrated and is back/forward focusing).

bran wrote in post #15006217
I understand the basics of aperture being the amount of light that passes through the camera. The small the f-stop the less light, also the more shallow the DOF.

No the smaller the f-stop (small f/number = larger hole) the more light, and the more shallow the DOF.