Extension Tubes - Help!

[kirbym2]

Hi All,

I don't have a macro lens, and was hoping extension tubes might be a budget friendly alternative. I've been using them with my 50mm 1.4 and 1.8. I find it extremely difficult to focus. I have to be within an inch of the subject to gain any focus, and even then, the slightest movement renders me completely OOF. Would I have better luck using the tubes with a 17-50 or a 55-200? I'd like to be able to catch macro insect shots, but that seems completely out of the question with the extension tubes.

Thoughts?

Thanks!

 

[tirediron]

What length extension are you using? When working in the macro range, depth of field becomes very, very shallow; as little as 1-2mm, whether using tubes or a "real" macro lens. The longer the focal lenght your're using the greater the camera to subject distance you will be able to achieve.

 

[2WheelPhoto]

Try using less tubes (not all 3 in the Kenko set at one time). Seems an inch is close.

 

[kirbym2]

I'm using Zeikos tubes... the set comes with 12, 20 and 36mm, can be used individually or in combination. Would you recommend using the tubes with the 55-200?

 

[2WheelPhoto]

I'm using Zeikos tubes... the set comes with 12, 20 and 36mm, can be used individually or in combination. Would you recommend using the tubes with the 55-200?

I use my tubes on the 55-200 kit lens, but not all 3 at once-, and i don't exceed 150mm and all my bugs are live and happy.

 

[kirbym2]

@2Wheel... Great shot! With this image, how far away were you from the subject?

 

[2WheelPhoto]

@2Wheel... Great shot! With this image, how far away were you from the subject?

at least a foot and a half, those things get scared and fly off. I cropped in too in PP

 

[Bend The Light]

I used to use an old 135mm lens on all three extension tubes. With a longer focal length you can be further from the subject but still get the same magnification. With my 135 on all the tubes I could be about 2ft from the subject. The Depth of Field is tiny, and it takes practice and a steady hand to get a decent focus. You tend to have to settle for "bits" in focus, and most out of focus. Rule of thumb...keep the eyes in focus unless your image is of the colouration, or the wing detail, or whatever.

I was sold a 90mm macro lens, cheap, manual, M42 fitting which I use on my canon 400d with an adaptor. This gives upto 1:1 macro. It is possible to get up close to these dragonflies, but you have to be patient and steady...they have big eyes and see everything you do.

Check my Flickr for recent dragonfly pics with the macro lens...just to show what you can do with practice...all handheld, all 90mm macro lens with manual focus.

 

[Noxire]

With extension tubes:
Shorter focal length=more magnification, shorter focusing distance
Longer focal length=less magnification, longer focusing distance
So if you feel you have to be too close i suggest you use your 55-200mm

The DoF is small because the lens is wide open even though you've dialed in a smaller f/stop, this is because the f/s is always at its widest for focusing purposes before you press the shutter button.

So when you remove the lens from the camera to attach it to the tubes; it's at f/1.4 rendering an unusable DoF.

ways to circumvent this:
1. Hold the DoF preview-button while removing the lens from the camera after dialing in the f/stop you want.
2. If 1. not possible, use mirror lockup, dial in f/stop, press shutter, remove lens.
3. Get an all manual lens where you can dial in f/stop directly on the lens.

(Ignore this post if you have some cool extension tube with electronics who does this stuff for you )

Hope I helped