macro and DOF

magicmonkey · Mar 15, 2006

Well I'm stumped, I just can't seem to get a decent DOF when doing macro work, not even at f22 with a 30 second exposure, I'm just starting to do a little macro work so I know very little about it, is it impossible to get a large DOF in macro or am I just being silly?:blushing:

Rob · Mar 15, 2006

What are you using to get a macro picture?

Rob

magicmonkey · Mar 15, 2006

Sorry, should have said! I'm using a Cannon 350D with a Sigma 70-300mm 1:4-5.6 mounted on a cheap and cheerful tripod...

spiky_simon · Mar 15, 2006

You're not being silly, but it's very hard to get decent DOF on macro images beacuse you're working so close. If you check out other photographers' images, you'll find that small (tiny!) depths of field are commonplace.

The lens you're using, while it will work as a macro, is not a dedicated macro lens - if you're enjoying your macro work, you might like to consider a deicated macro lens. i have that lens and you have to put it right at the top end of the zoom to put it into macro mode, which makes the working distance pretty massive!

magicmonkey · Mar 15, 2006

yeah, the working distance on this shot was about 4-5 feet away!

I don't really have any money to spare on lenses at the moment so short of winning the lottery I think I'm just going to have to put up with the short DOf and try to work the composition around it, bit of a pain really as I'd like this shot if the stamen was in focus but as it stands it's just one for deleting.

Big Mike · Mar 15, 2006

There are several different ways to do "macro" photography.

A real "macro lens" as mentions is probably on of the best ways...but it's expensive.

You could use extension tubes, with a lens that you already have. They let you achieve focus at a closer distance.

You could use close up filters on the front of a lens that you already have. They are cheaper than a macro lens or tubes but image quality will suffer a little or a lot, depending on the quality. I've got a set of them, they are OK for my needs.

You could even reverse mount one lens onto another. You can even buy "macro coupler rings" which let you screw to lenses front-to-front with the filter threads.

magicmonkey · Mar 15, 2006

Big Mike said:
There are several different ways to do "macro" photography.

A real "macro lens" as mentions is probably on of the best ways...but it's expensive.

Yeah, way too expensive for my unfortunately, even my best friend (ebay) is way too expensive!

Big Mike said:
You could use extension tubes, with a lens that you already have. They let you achieve focus at a closer distance.

You could use close up filters on the front of a lens that you already have. They are cheaper than a macro lens or tubes but image quality will suffer a little or a lot, depending on the quality. I've got a set of them, they are OK for my needs.

Tubes doesn't sound like a bad idea, what affect does it have on the image quality though?

Big Mike said:
You could even reverse mount one lens onto another. You can even buy "macro coupler rings" which let you screw to lenses front-to-front with the filter threads.

Coupler rings sounds horrible! I'd be worried that the filter rings wouldn't hold the weight of the lens and end up tearing thhemselves apart! How would you go about reversing lenses without a coupler ring? Would it litteraly be just holding one lens infront of the other? Obviously different combinations of lenses would work differently so which would give the best results?

Sorry, far too many questions her now!!! :blushing:

Rob · Mar 15, 2006

Front to back coupling (ooh err missus) isn't too bad actually. I've used rubber bands in the past!!

Rob

magicmonkey · Mar 15, 2006

That must have been a big rubber band!

airgunr · Mar 15, 2006

When shooting macro your DOF is measured in fractions of an inch to maybe just over an inch even at your smallest apature. It is just the nature of the beast.

Big Mike · Mar 15, 2006

Tubes doesn't sound like a bad idea, what affect does it have on the image quality though?

Since tubes don't add any glass in the path of light, the image quality should not be affected.

Coupler rings sounds horrible! I'd be worried that the filter rings wouldn't hold the weight of the lens and end up tearing thhemselves apart! How would you go about reversing lenses without a coupler ring? Would it litteraly be just holding one lens infront of the other? Obviously different combinations of lenses would work differently so which would give the best results?

Yes, it can be pretty delicate, but as the whole thing is on a tripod and not moving very much, it seems to be OK. I like to use a small prime lens (50mm) reversed onto another lens, so the weight on the coupler is as low as possible. Some people on this site have uses cardboard and tape to do this.