rvhowdy

I just purchased a set of extension tubes for Nikon AF lens. The set includes a 36mm, 20mm, and 12mm. Having never used extension tubes before, I would like to hear comments from those who use them. When is it best to use all three together. I put all three on with my 50mm lens and realized the focus point is so close I can only focus in on a portion of one petal of a flower. I have a learning curve ahead of me. Any pointers would be appreciated.

PhotomanTom

There are many things about macro photography that must be mastered, for now you might consider just getting familiar with the tubes. Use a ruler placed at 90degrees to the camera to familiarize yourself with the field of view using each tube separately and in various combinations. Then set up the same test but with the ruler facing away from the camera. Use each tube separately and in combination to check the depth of field. All testing should be done on a tripod. You’ll lose a significant amount of light, especially when using all three, which will result in slow shutter speeds unless raise ISO. I personally would use base ISO from best results since the ruler won’t move much!

gvarner Loc: Central Oregon Coast

Yes, you need to study up on what macro photography is all about. It's a specialty.

Bugfan Loc: Toronto, Canada

Extension tubes as you discovered allow you to get closer and thus magnify.

I would suggest you use each tube individually on a single lens. Then use them in combination. Have a look at what happens. To really appreciate what is possible, set your focus to minimum and leave it there, focus instead by moving the camera in and out. That's how tubes are usually focused anyway and that will demonstrate to you exactly what the effect of each tube is.

The tubes are also expensive light wise. So as you try the different combinations record your exposure data. That will give you a good idea how much light any combination will cost you.

Generally using tubes isn't very helpful with a fifty or shorter lens, you have to go too close. Using the shortest tube helps but not always. Try instead a 100 mm or longer lens, that gives you a better working distance. The shorter lens is only handy if you have something really tiny like a flea to take a picture of.

You can use as many tubes as you like. There is a limit in the sense that eventually you lose so much light you can't see your subject under a high noon sun but until you get to that point you can just keep magnifying, it does not affect the quality of your image.

Focus can be helped with a focusing rail. The way you focus is by moving the camera forward and backward. That is a hell of a struggle hand held. It's usually easier on a tripod compete with a focusing rail. The rail is also useful for focus stacking since it enables you to move the focus point in tiny increments. The link below will show you some options. Don't be shocked by the prices, some are a lot more affortable. Just make sure that whatever you choose, is rigid.

https://www.bhphotovideo.com/c/buy/Other-Macro-Accessories/ci/3067/N/4289360636?origSearch=focusing+rail

I think you'll find with enough practice it will become intuitive what combinations you need to achieve the picture you want. Good Luck!

rvhowdy

Thanks for the quick response. I am looking forward to learning. I am a landscape guy and also do do family portraits. But, I have really admired photographers who do macro. I'm in the Cocoa Beach, FL area. If any macro expert around my area would like to shoot with me, I'm a good student.:)

twowindsbear

Also keep in mind that given a lens of X focal length + extension tube(s) of X length = a 1:1 reproduction ratio at X focus distance.

So, with your 50mm lens, if you use a combination of extension tubes to equal 50mm then a 1" object will give you a 1" image on your camera's sensor at a distance of 50mm from the front of your lens.

Hope this helps a bit.

Macro photography can be quite a bit of fun!

clickety

I assume this is using a full frame camera. If using a camera with a 1.6 crop factor sensor would the distance from the front of the lens become 80mm? Thank you.

chapjohn Loc: Tigard, Oregon

ET's do two things--shorten your focal distance and and lessen your DOF. If you stack ET's make sure it doese not exceed the focal length of the lens. On a 50mm lense stacking a 36mm and a 20mm ET's will put the focus point inside the lens and you can not focus. One of my favorite ways to shoot flowers is to use the 13mm ET on a 50mm lens.

twowindsbear

No - the 1:1 reproduction ratio stays the same, you'd just get a life size image of a smaller object, because the sensor is smaller than the ~24 x 36mm film or full frame image area.

amfoto1 Loc: San Jose, Calif. USA

The very general "rule of thumb" with extension tubes is that the amount of extension same as the lens focal length will give you 1:1 magnification. And this doesn't take into account a lens' ability to focus close on it's own, without extension. Putting 68mm of extension behind a 50mm lens "pushes" it well beyond 1:1 magnification and will make for very little working room between the front of the lens and the subject. It also will make for very shallow depth of field. Especially a 50mm f/1.8 or f/1.4 will render extremely shallow DoF. Did you stop the lens down to increase DoF? I'd suggest at least f/5.6... maybe even f/8 or f/11.

Try to use as little extension as possible and only one tube at a time... The longer the lens focal length, the more extension will be needed to make any significant difference. Conversely, short focal lengths only need a little bit of extension.

Here are some examples:

20mm lens with 12mm extension (used so that more of the background remained recognizable, but petals of the flower were actually touching the front element of the lens):


50mm lens with 20mm extension:


85mm lens with 20mm extension:


90mm 1:2 macro lens with 20mm extension:


70-200mm lens with 25mm extension:


300mm lens with 36mm extension:


500mm lens with 36mm extension:


Note that using the tubes on longer telephotos doesn't really make them into "macro" lenses... but it does make them able to focus closer and give higher magnification than they normally are able to do.

The best way to learn about those extension tubes and what they can do is to simply get out and shoot/experiment with them. Try them with various lenses. Try different amounts of extension. But in general I recommend using only a single tube as much as possible (makes for better AF performance, less light fall off inside the tube, and depending upon the quality of the tubes, a very heavy lens on several tubes might damage the tubes or cause a dropped lens!)

BassmanBruce Loc: Middle of the Mitten

Consider posting this question and others here:

http://www.uglyhedgehog.com/s-102-1.html

These folks are helpfull friendly and very good.

RWR Loc: La Mesa, CA

Not sure what lens you were reading about, but with 50mm worth of extension tubes on my 50 f/2.0 Summicron-R, the subject is about 75mm in front of the lens. Even with lenses like the Makro-Kilars and Micro-Nikkors, where the front element may be recessed as much as 40mm, there is room to go well beyond 1:1 before hitting the lens. Obviously if you go much closer lighting can become more difficult. I haven’t checked for just how much extension one can use, as I either reverse mount or stack lenses when going closer than 1:1.