Extension tubes - how to actually use them in practise?

SlowSteve

SlowSteve

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Steve
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Hello all.

I have to take some close up pictures for Mrs Steve - and seeing as in a couple of weeks I'm going to be wanting to get some expensive lumps of glass, I could do with being in her good books - I would like to do a good job.

The pictures will be of chocolate for her website - she is going to start a chocolate company. So the pictures will be of posh looking chocolates on fancy plates and folded napkins etc etc.

My kit currently is:

Canon 400d
50mm f1.8 prime lens.
Cheap-ish tripod
I am getting a set of cheap extension tubes today.
I do not have seperate

I get the concept of using the tubes, but I just wanted to check how to actually use them in practice for my specific task.

I unmount the lens, chuck the extension tube/tubes on, then re-mount the lens on these.

But... becuase they are cheap tubes, I don't have autofocus or control over aperture.

Focus I guess is just done with manual focusing. Which is fine. I can do that.

So my first question is how do I set depth of field? I saw a YouTube video where a guy mentioned using the DOF button on the camera, but not sure how to actually do that. Do I set the DOF before I unscrew the lens?

My other question is about lighting. I do not have a flash apart from the in-built flash on the camera. I have any number of incandesent and flouresent lights that I can manovour into position, and I can always diffuse this as needed with cotton bags over the lights.

There is obviously day-light as well.

Am I right in thinking that daylight is preferable over artificial light for this kind of work? I have read that my Canon is especially bad at handling Tungsten lighting, and from the images I have taken already, I agree - even with the tungsten setting in the WB menu set, the colour cast is still very noticable.



If anyone has any thoughts/comments/advice etc that would be very helpful. Also, if anyone has some good links to other sites, or can reccomend some good books that might help me with this task, that would also be great.


Many thanks in advance

Steve
 
Manual focussing and manual metering too.

Put your camera on manual. Depth of field with extension tubes is tiny so you'll want a small aperture. Now adjust shutter speed to get the exposure according to your camera's meter.

Focussing may actually be best achied by moving the camera to or from the subject. There will be very little lattitude between being in focus and blurred.

Strong light is a big asset and so is a rock steady tripod or other mount.
It is actually possible to buy mounts that fit on to your camera and tripod that allows to camera to be slowly and finely moved to and from the subject to aid focussing (Manfrotto do one).

When you put the tubes on for the first time have a look through the viewfinder at a subject and you'll soon see the difficulties of this type of photography.
 
To set the aperture, have the lens mounted normally, press and hold the DOF button, then unmount the lens. You can then attach your tubes, remember though that with close work you will not have much DOF, and usinga small aperture say f11 is going to make the viewfinder very dark. However since chocolate stays stationary you can have several goes...... depending on your appetite resistance factor :D
 
Definitely use a tripod and a cable release, or use the timer to stop you moving the camera when clicking the shutter.

Re light: shoot raw and make sure the subject is being lit by one source, i.e. daylight OR tungsten OR flourescent OR flash - don't mix them or you'll never get the colours correct
 
Thanks for the quick responses.

"putting the camera on manual" is still something I am struggling with. I understand the theory - I just can't find instructions on how to actually DO that on my Canon - I set it to manual, and seem to be only able to change Aperture!!

OK - so I now get how to set DoF - thanks for this.

Not sure I yet understand the issues regarding metering - I don't yet understand how the tubes alter the metering, but I guess I will understand better when I am actually using them.

The idea of such a narrow depth of field is a bit worrying - I was hoping to have a DOF of perhaps 3" - 6", so I can get the chocolates and some of the plate in focus, and then have a lovely tail off after that.

If I set the lens to something like f/22, would that help?

Thanks

Steve
 
If I remember correctly, to change the shutter speed you hold down one of the top buttons and move the wheel as you would for aperture - don't ask me which one though, I've never had a 400D, but I did have a 350...

If they are cheap tubes, they may not allow you to electronically change the aperture either.... And without manual aperture settings on the lens (like the old days) you may well be stuffed...

Steve
 
I think the first thing I am going to do is run a set of contacts through my cheap "non-electrical" tubes so I can use the lens functions.

I am discovering that the cost of anything to do with photography is insane. The difference between a £15 set of extension tubes and a £190 set is some a few bits of wire to carry a current.

15 minutes with a drill and the soldering iron will soon sort that out!
 
SlowSteve said:
I think the first thing I am going to do is run a set of contacts through my cheap "non-electrical" tubes so I can use the lens functions.

I am discovering that the cost of anything to do with photography is insane. The difference between a £15 set of extension tubes and a £190 set is some a few bits of wire to carry a current.

15 minutes with a drill and the soldering iron will soon sort that out!
Click to expand...

DIY = Excellent :)

Also if you don't fancy it, you can find generic tubes that maintain electrical contact for about £50 too. They are naff for auto focussing, but thats pretty useless in macro work anyway.
 
Just use the nifty 50 and crop......unless they are very small chocolates :),

at 1:1 with a crop body a object 22mm x 14mm will fill the frame with about 3mm of it in focus................
 
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