extension tube question

hello all,

can i use more then 3 extension tubes at one time? i have the kenkos 12mm, 20mm, and the 36mm. thought i read somewhere that you could. thanks

Search under topics here for more tips on macro shooting.
Some very basic tips:

• tripod*
• cable release*
• patience*

Enjoy!!

I think the OP was asking whether he could use MORE than 3 tubes at a time.

If that was the case, then theoretically YES you can, although you would probably run into difficulties with your Working Distance etc. when using very long tubes with shortish FLs.

csfbphoto said:

Search under topics here for more tips on macro shooting.
Some very basic tips:

• tripod*
• cable release*
• patience*

Enjoy!!

Click to expand...

Yes. Try all of the "optical marriages" you can think of. Some work and some don't. Of those that work, some will work well. Having you thought of adding a teleconverter to the mix? Have you tried reversing a 50mm on another lens? or on the camera? Macro is a blast and can be done a lot of ways.

--



Happy shooting,
Mark
http://www.mplonsky.com/photo

when you start adding multiple tubes? I don't have any tubes at this moment but considering them instead of a lens with macro capabilities.

I purchased a second set of Kenkos to see what was possible. I ended up selling them as the light falloff was just too much and I could not achieve anything more than with just 3.

denny2020 said:

when you start adding multiple tubes? I don't have any tubes at
this moment but considering them instead of a lens with macro
capabilities.

Click to expand...

You can use 3+ tubes at the same time, but focusing gets real difficult, also light fall off is another problem, I have the Kenko tube myself, I get best result using a single tube with my 50mm F1.4, for me, it's just for fun to try macro, if you are serious about doing any macro work, I would get a real macro lens, it will work much better, especially working distance and focus so much easier.

Have fun.

Tubes cause no light 'fall off'. What causes the need for additional exposure is adding addditional magnification. You would have the same issue with needing more light with a 65mm macro at 5:1 that you would have with a 'normal' lens on a stack of tubes. That is why so many people shooting super macro also own the ring ight or twin macro light.

Vignetting is not a problem since the field of view is reduced as magnification is increased. The main use for a stack of more tubes is when you are starting with a long lens that has poor close focus capability. The standard 68mm set has less effect on a 600mm lens than it does on a 60mm so you might want to try extra if you are shooting over about 100mm. More than 68mm worth of tubes can help a 200mm or 300mm. Each lens has a limit to the amount of extension it can accept before it is focused on its front element. For a 10mm lens, the smallest 12mm tube is longer than is practical but for a 600mm that same tube hardly changes anything.

There also is a point at which the image quality of a lens designed for distant objects becomes objectionable. Optimal working distance is a part of lens design and different lenses of the same focal length fall apart at different spots. You can add tubes but you may not want to.

There is also a point where the extension reduces the depth of field to a point that there is nothing in focus. This limits the macro use of really long lenses. Below is a macro of a crocus using tubes on a 600mm. It shows the field of view at about 4 feet and the lack of depth of field at f/8. The image fails for a combination of the last two points.



The question is back to you. What are you doing and would a shorter working distance help you do it or get in the way?

--
Doug Smith
http://www.pbase.com/dougsmit

Hi Doug,

I have never tried my extension tubes with my Sigmonster (mean to get around to that), but they work like a charm on my 400 5.6. I am posting a link to this image since a reduced size image I could reproduce here would not do it justice

http://www.pbase.com/tommy2guns/image/61701312/original

The working distance was probably around 4-5 feet with all three of my el cheapo tubes. I suspect I could easily put three more on (something else I need to get around too) and get acceptable results.

What is sharp is nice but there sure is narrow depth of field. Dragonflies are hard to get sharp since they tend to be X shaped and on the move. I have yet to get a shot I really like of one.
--
Doug Smith
http://www.pbase.com/dougsmit

Canon "officially" says not to use more than 2 ext. tubes at a time. reason = they are worried about the elec. signals getting through in time. What you can get away with is another thing.

This is with a Sigma 150 macro and a Sigma 1.4 TC

http://www.pbase.com/tommy2guns/image/46758849/original

Thanks for the info, obviously I didn't know canon said no more than 1 tube at a time, but like I said, I have better luck with a single tube so I don't even like to use multiple tubes, but I did try it's doable, just a little more difficult.

Hey Dan. Can you post some examples with your 50mm. Thinking about getting a set of tubes for my 50mm and 85mm. Thanks in advance.

Dan_168 said:

You can use 3+ tubes at the same time, but focusing gets real
difficult, also light fall off is another problem, I have the Kenko
tube myself, I get best result using a single tube with my 50mm
F1.4, for me, it's just for fun to try macro, if you are serious
about doing any macro work, I would get a real macro lens, it will
work much better, especially working distance and focus so much
easier.

Have fun.

Click to expand...

I have been playing with my new 100mm macro with extension tubes. Here is my last effort with 68mm of extension tubes. I call it liquid photographer.



Falling drop in front of a mirror with off camera flash facing toward the camera.