Wide Angle AND close focus?

LiveAwake

Hey all, I'm looking for a tip on how to get even closer to my subjects in my wide angle shots. I am currently using the Tokina 11-16mm lens on my D300, and it's a GREAT lens that lets me get about a foot away from my subject. But what can I say, I'm a junkie and I want to fill even more of my frame with small/close subjects with a wide angle of view.

So . . . what can I do? Is there a lens that does even better than the Tokina? Is there some kind of adapter I can add to chop off another 6 inches from my close focus distance?

Tell me what you know!
Thanks.

CWSkopec

I've often wondered if an extension tube would allow what you're looking for. From what I understand, they make it possible for a lens to be closer to the subject but are mainly used for macro work. I think it would work in theory, but is as-of-yet untested by me. Hopefully one of the resident experts will stop by and let us know if this is a bad idea

ziggy53

You can try adding extension tubes but I suspect you will not like the effects that are induced. Most likely you will get soft edges and additional CA. (Zoom lenses are not designed to be used with extension tubes, as a rule.)

Specifically what are you trying to photograph?

mehampson

With such a short focal length, even a really short extension tube is likely to place your focus distance on the front element of the lens, or even inside of it.

When you say you want to fill the frame with small subjects at wide angles, what exactly do you have in mind? Especially how 'small' you're thinking.

LiveAwake

mehampson wrote:

With such a short focal length, even a really short extension tube is likely to place your focus distance on the front element of the lens, or even inside of it.

When you say you want to fill the frame with small subjects at wide angles, what exactly do you have in mind? Especially how 'small' you're thinking.

Well, I'm not trying for just one specific shot, but an example would be if I find an interesting mushroom while walking in the woods. I would love to be able to get even a fairly small one to fill most of the frame, but still be able to see a wide angle of woods in the background.

I have a macro lens that I can use when all I care about is getting really close in, but I'm looking for a different effect with the wide angle and large depth of field that comes from a very short lens.

mehampson

Hmm, well, maybe a split diopter would do it for you. I don't have any practical experience with them, though.

LiveAwake

mehampson wrote:

Hmm, well, maybe a split diopter would do it for you. I don't have any practical experience with them, though.

Hmm, I don't know much about split diopters (ok, scratch that, I don't know ANYTHING about split diopters except what I read in my 30-second google search to find out how it works) but I don't think that's quite what I'm after. Here's an example of the type of picture I'm trying to take:

But in this picture, the mushroom was at least 6 inches tall. I'm looking for a similar effect with even smaller objects.

mehampson

Yeah... it's going to be tricky, and to be honest I'm not sure if there's an economical solution for you. Sigma makes a diagonal fisheye that has a 6" MFD, with about a 1:2.5 magnification ratio, but that costs about $600. Maybe see if you can rent that to see if it's what you're looking for. And Nikon's got a long history of lenses, so there be something obvious in there that I've never heard of (being a Canon shooter).

The problem is that the things you're looking for a working against each other. Depth of field is inversely related to focus distance, for example. It's also going to be extremely difficult to find a lens that can do what you want without some really obvious distortion, but that might not be a problem for you (which is why I suggested a fisheye).

It also might be a software solution. There's good focus-stacking programs out there, or you can think about macro panoramas.

paddler4

I think you may be confusing perspective and background blur with depth of field. Assuming you position the camera to have the subject the same size, DOF is not much affected by focal length. See http://www.cambridgeincolour.com/tutorials/depth-of-field.htm. What WILL change a lot with focal length is background blur. See http://toothwalker.org/optics/dof.html. In any case, it may be a moot point. At macro distances, DOF is extremely thin, and while a short lens will give you somewhat less background blur, you won't be able to see much that is far from the focal plane. In fact, at macro distances, the problem is that it is hard to keep the entire subject in focus, particularly if the subject is not flat and parallel to the focal plane (like mushrooms). At 1:1 and closer, one often ends up stacking more than one image, using software like Zerene, just to get a good portion of the subject in focus. check out the macro section on this forum.

Robinivich

In underwater wide angle photography the circular dome ports used impose special requirements on the lenses. Specifically, lenses need to be able to focus only a few inches away from the front element. Underwater photographers use diopters to accomplish this, usually a +2 diopter which is a screw on lens that goes on your filter threads.

Canon makes a 500D diopter in a variety of thread sizes, and it's a two-element design so you won't give up much optical quality. This is your best bet. They're also better suited to zoom lenses than extension tubes.

LiveAwake

Robinivich wrote:

In underwater wide angle photography the circular dome ports used impose special requirements on the lenses. Specifically, lenses need to be able to focus only a few inches away from the front element. Underwater photographers use diopters to accomplish this, usually a +2 diopter which is a screw on lens that goes on your filter threads.

Canon makes a 500D diopter in a variety of thread sizes, and it's a two-element design so you won't give up much optical quality. This is your best bet. They're also better suited to zoom lenses than extension tubes.

Thanks for the recommendations - I will see if a diopter attachment will accomplish what I'm after, since that seems to be the easiest/cheapest option, then work my way up from there.

craig_d

paddler4 wrote:

Assuming you position the camera to have the subject the same size, DOF is not much affected by focal length... What WILL change a lot with focal length is background blur.

Right, because DOF is affected by three factors: focal length, focus distance (that is, distance to subject), and aperture. If aperture is held constant, then when you "position the camera to have the subject the same size" at different focal lengths, you are basically varying focus distance to compensate for the change in focal length, hence DOF doesn't change much. But as you note, background blur will still be affected.