How To Get The Right Amount Of Focus?

I'm trying to take close up pictures, let say a blade of grass with some drops of morning dew on it. But when I bring my camera close to the blade of grass, it doesn't have enough focus to bring the subject in focus. Is there a certain lens for this or something I'm missing? I've been photographing mainly human subjects for 6 months now. Any help would be great. Thanks.

Your problem is simply the very shallow depth of field at the distances you are working at. The more wide open the lens is, the shallower it gets. So if you find you need more DoF, close the aperture down.

Lets say you were using f/5.6, going to f/8 will improve things. Going to f/16 will improve it more.

Edited to add: I've just reread your post. Do you mean the lens simply refuses to focus at the distance you want? If thats the case, you need to know that all lenses have a minimum focusing distance and some are better than others. A relatively cheap way of overcoming this is to buy a set of tubes. These come in sets of three, each a different length. They effectively allow you to focus a lot closer. But remember the issue I thought you were referring to above.

Check the "Minimum Focus Distance" of your lenses.

The 50mm you have has an mfd of 1.5 ft.

Edit

The 28-135 = 19.7"

Yep, Minimum Focus Distance. It's marked on your lens. You need something with Macro capabilities. Either that or you have to back up, then crop your shot in post processing.

Canon also sells a couple of Close Up Lenses, the 250D and the 500D, they mount to the front of your lens like a filter.

Macro, a 60mm ef-s macro or a 100mm ef macro would do the job. There is lots of data around about these two fine lenses and several other "macro" lenses so just read up on them.
There is a difference in a "macro" lens and the macro of your lens. The macro of your lens is more or less how close you can get to the subject and still focus the lens basically the same as MFD. (minimum focus distance).
A "macro" lens allows a much closer MFD allowing a magnification near 1:1.

I am not macro expert but hope this helps you.

Lowner is right but I think DunnoWhen (cam) is onto your specidic problem... to get the subject to appear bigger (macro) you are wanting more magnification by bringing your camera closer to the subject...

Extension rings can help with this to make your minimum focusing distance shorter - so you can bring your camera and lens closer to the target.

longer lenses dont solve this either.... getting a 400mm is great but you might have to be 1.8m away to focus on something...

the canon 100 macro lets you get to 1:1 magnification at minimum focus distance- so you can focus on something and it will fill your sensor plane with something the size of your sensor... 1cm pea will be 1cm worth of space on your sensor (about 1/3 across the recorded image)

the 300f4Lis can get close to macro.... or even the 50mm with some extension tubes...

apart from that - im afraid you will have to just take the shot in focus - and crop it on the PC afterwards to achieve the framing you want.

Thanks for the quick replies guys. I believe it just has something to do with the Minimum Focus Distance of my lens, just like you had said DunnoWhen. Is there a way to get around this with the lenses I have already? What are the tubes you are talking about Lowner? How do they work? I just want to get closer to my subject and be able to focus, but my lenses just focus. Lets say I want to get my camera a good 6 inches away from my subject, my lens just wont focus to that distance. That's the problem I'm having. Would I have to buy another type of lens for this? If so, which is a good one?

Sorry if I jumped around a little bit. I swear I have A.D.D. so I'm sure I am thinking about riding bikes while typing out this sentence.)

taknbyd wrote in post #8188949
Thanks for the quick replies guys. I believe it just has something to do with the Minimum Focus Distance of my lens, just like you had said DunnoWhen. Is there a way to get around this with the lenses I have already? What are the tubes you are talking about Lowner? How do they work? I just want to get closer to my subject and be able to focus, but my lenses just focus. Lets say I want to get my camera a good 6 inches away from my subject, my lens just wont focus to that distance. That's the problem I'm having. Would I have to buy another type of lens for this? If so, which is a good one?

Sorry if I jumped around a little bit. I swear I have A.D.D. so I'm sure I am thinking about riding bikes while typing out this sentence.)

You would need something like this... http://www.amazon.com …ics&qid=1246203​576&sr=8-1

the 18-55mm IS lens has a closer minimum focus distance than most lenses, and is quite cheap. just a thought.

Thanks guys for all the great info... While I was typing up my last reply you guys answered my question. Thanks a ton. Now to get the wife to let me have some money... Anyone got a suggestion for that one? LoL

taknbyd wrote in post #8188974
Now to get the wife to let me have some money... Anyone got a suggestion for that one? LoL

Easier to beg for forgiveness than to ask for permission.

All the tubes do is increase the gap between the lens and the point at which it focuses (what used to be called the film plane). Increasing the distance behind the lens effectively shortens the focusing distance.

Canon EF tubes need to have the electronic contacts, which probably increases the cost, but otherwise they are very cost effective.

taknbyd wrote in post #8188860
I'm trying to take close up pictures, let say a blade of grass with some drops of morning dew on it. But when I bring my camera close to the blade of grass, it doesn't have enough focus to bring the subject in focus. Is there a certain lens for this or something I'm missing? I've been photographing mainly human subjects for 6 months now. Any help would be great. Thanks.

Your question has essentially two parts and hence needs 2 answers.

First, as other have mentioned, you should be aware of your MFD of your lenses. The 50/1.4 has an MFD of 1.5ft. (0.45m). So, the lens can not focus closer than 18" away. That is NATIVELY.

You can always added "close-up" lenses such as others have suggested (which DOES degrade image quality), or you can use some Macro Extension Tubes to do the same thing (that is let you get closer) but without IQ degradation. Get yourself a full set of Macro Extension Tubes and start to explore.

Some people had mentioned that you should stop down, they didn't understand that you were attempting to focus at a distance closer than MFD. They said you should stop down. The reason nothing was in focus for you is that you were trying to focus at a distance closer than MFD. Stopping down would not have helped in your situation. But, once you do set yourself up to handle focusing closer (via Extension Tubes or Diopter Lenses (thats the technical name for "close-up" lenses)), you still need to control DOF via stopping down the aperature (f-stop).

Effective use of DOF is key to good Macro work. In general, the closer you get to your subject, the thinner the DOF. As you start to get magnification levels of 3:1 and higher, you will find that aperature of f/8 or less is remarkably useless, you will need f/11 and f/16 just to have any kind of usable shot.

The second question as far as special lenses you could consider a Macro lens, but your lens + Macro Tubes will offer similar results.