Advice: extension tubes Macro

[Loswr]

Is the air in the Canon tubes better than the air in the Kenko tubes? For most applications, the Kenko tubes are just fine (the only reason I went with Canon tubes is that my main use is to reduce the MFD of a supertele, and I wanted to be sure of the mount strength - not an issue of concern for macro lenses).

For starters math is not my strong point. Just curious as to how much the MFD is reduced on a 600mm lens when using extension tubes. I currently have two setups.
1. 300/2.8 w/ 2x TC, MFD ~ 10ft.
2. 600/4(non-IS), MFD ~ 20ft.
Will an extension tube(s) get my 600 MFD to ~10 ft?
My slight understanding of the math says no.
Thanks for any enlightenment you may provide.

An EF 25 tube will get your 600/4 to an MFD of ~15 feet.

 

[Skatol]

Is the air in the Canon tubes better than the air in the Kenko tubes? For most applications, the Kenko tubes are just fine (the only reason I went with Canon tubes is that my main use is to reduce the MFD of a supertele, and I wanted to be sure of the mount strength - not an issue of concern for macro lenses).

For starters math is not my strong point. Just curious as to how much the MFD is reduced on a 600mm lens when using extension tubes. I currently have two setups.
1. 300/2.8 w/ 2x TC, MFD ~ 10ft.
2. 600/4(non-IS), MFD ~ 20ft.
Will an extension tube(s) get my 600 MFD to ~10 ft?
My slight understanding of the math says no.
Thanks for any enlightenment you may provide.

An EF 25 tube will get your 600/4 to an MFD of ~15 feet.

Thanks Neuro, exactly what I was looking for. So the Kenko 36 would get me to about 12?

 

[mackguyver]

....Middle East excavation site in progress.......

Oops, missed that ???

 

[Mt Spokane Photography]

I decided to refresh my experiences with extension tubes and extenders on my 5D MK III and 100L. I used a cheap 13mm extender and a Canon 1.4X MK III on my 100L. It would not autofocus at all, it just went into a high speed hunt mode, almost a vibration.

Then, I tried live view with live AF. It slowly focused, sometimes, but was only suitable for use with a tripod.

Just using the extender was much better, no issues focusing, but still difficult when hand held. Obviously, I got the best results with the bare lens. In the end, I just deleted all the shots, I wasn't happy with any of them. I'm impatient, and do not want to setup a tripod or slider. A thunderstorm was brewing in any event, so I gave up.

I was playing around with my old but newly acquired 5D classic this morning and my 24-70L MK II. Its not particularly good for close-ups. a moth flew right in front of the lens as I was trying to focus on a bumble bee, so it got in the photo.

 

[Jack Douglas]

Here's the 300 with a 36 Kenko at maybe 4-5 feet and F4, very slightly cropped to reframe. Just goofing off here. Depth of field is certainly shallow but sometimes that's OK... or not.

These white breasted nuthatches are not a big bird, about 5 1/2 inches tip to tip.

I like the 300 2.8 as my general outdoor lense for macro type shots of bugs and flowers but sometimes the MFD is an issue and then the extension tube helps. I don't like the floppiness of the stacked Kenko tubes with the 300.

Jack

 

[Sabaki]

Just get the Canon's.

I've got a 12mm & 25mm and it works 100%

I've never used the Kenko's so can't comment on those but it does seem that value for money is a factor.

 

[Eldar]

Just get the Canon's.

I've got a 12mm & 25mm and it works 100%

I've never used the Kenko's so can't comment on those but it does seem that value for money is a factor.

I have Canon and my son has Kenko. Kenko feels a bit less solid, but I doubt you´ll run into problems. If you plan to use heavier lenses, I´d feel more comfortable with Canon though.

 

[Skatol]

Here's the 300 with a 36 Kenko at maybe 4-5 feet and F4, very slightly cropped to reframe. Just goofing off here. Depth of field is certainly shallow but sometimes that's OK... or not.

These white breasted nuthatches are not a big bird, about 5 1/2 inches tip to tip.

I like the 300 2.8 as my general outdoor lense for macro type shots of bugs and flowers but sometimes the MFD is an issue and then the extension tube helps. I don't like the floppiness of the stacked Kenko tubes with the 300.

Jack

Thanks for the example Jack. I am currently on a hummingbird kick right now. My best results have come from the 300 w/2xTC, F/11. The problem is that focusing is super slow. I'm hoping to achieve better results with the 600 coupled with an extension tube to get close to the same MFD. Focusing should be much faster assuming the extension tube doesn't poke a hole in my theory.

 

[Skatol]

Just get the Canon's.

I've got a 12mm & 25mm and it works 100%

I've never used the Kenko's so can't comment on those but it does seem that value for money is a factor.

I think I may go this route. It's only a $50 difference (quite small in the grand scheme of photography gear) between the two Canon extenders and the Kenko set.
Thanks for the input.

 

[NancyP]

I use a teleconverter to get the MFD closer on my 400mm f/5.6, but I lose AF. I happen to have Kenko rings set, and they work well and are stout. Perhaps a Canon ring might be slightly sturdier for lenses exceeding 1.5 to 2 kg, but my Kenkos hold the 400 f/5.6L just fine. I use my 180 f/3.5L with a 1.4x teleconverter also, but that's to allow equivalent magnification further away (from the snake).

Some users stack the 1.4x and 2x TCs by putting the 12mm Canon extension tube between the two extenders (extenders can't stack directly).

 

[Loswr]

I use a teleconverter to get the MFD closer on my 400mm f/5.6, but I lose AF. I happen to have Kenko rings set, and they work well and are stout. Perhaps a Canon ring might be slightly sturdier for lenses exceeding 1.5 to 2 kg, but my Kenkos hold the 400 f/5.6L just fine. I use my 180 f/3.5L with a 1.4x teleconverter also, but that's to allow equivalent magnification further away (from the snake).

Some users stack the 1.4x and 2x TCs by putting the 12mm Canon extension tube between the two extenders (extenders can't stack directly).

TCs don't alter the MFD, but they do increase the magnification.

It's only the MkIII TCs that can't be directly stacked with each other, older versions can.

 

[mackguyver]

I use a teleconverter to get the MFD closer on my 400mm f/5.6, but I lose AF. I happen to have Kenko rings set, and they work well and are stout. Perhaps a Canon ring might be slightly sturdier for lenses exceeding 1.5 to 2 kg, but my Kenkos hold the 400 f/5.6L just fine. I use my 180 f/3.5L with a 1.4x teleconverter also, but that's to allow equivalent magnification further away (from the snake).

Some users stack the 1.4x and 2x TCs by putting the 12mm Canon extension tube between the two extenders (extenders can't stack directly).

TCs don't alter the MFD, but they do increase the magnification.

It's only the MkIII TCs that can't be directly stacked with each other, older versions can.

Thanks for reminding me - I have tried the stacked TCs on the 300mm f/2.8 IS II with ho hum results, but I had forgotten to try them on my 180L. I have a feeling that it might work better with the subject being so much closer (i.e. less heat/humidity to muck things up in the photo).

 

[AcutancePhotography]

If you are going to stack multiple tubes and use large/heavy lenses, I would highly recomment getting some sort of support for the lens.

 

[mukul]

I don't have an opinion on what you should get, but I'm curious, why do you need/ wan't to get so close?

I guess the ext tubes make in general more sense on those lenses where mfd is less close than my macro lens
I just find the mfd of 1ft (0.3m) not close enough for archeologic artifacts

I'm a bit confused by the mfd for this lens with the extension tubes.

From the manual, mfd with no extension tubes is 300mm (magnification 1.00).

With a 12mm tube, it's 302mm (magnification 1.17).
With a 25mm tube, it's 307mm (magnification 1.37).

So they don't reduce the mfd at all, just increase the magnification. Is this the normal way macro lenses work? It's been too long since I used extension tubes on mine.

They does reduce MFD, I know this from firsthand experience. If I mount 50mm f/1.8 on 69mm extension tube the MFD is below 10 inch (from my estimates, and I'm sure It will not be greater than 10") while MFD for 50mm 1.5ft

Here is a good ref. for extension tubes
http://www.cambridgeincolour.com/tutorials/macro-extension-tubes-closeup.htm#calculator-extension
and
http://www.cambridgeincolour.com/tutorials/macro-lenses.htm#calculator-magnification

 

[Steve Balcombe]

It's only a $50 difference (quite small in the grand scheme of photography gear) between the two Canon extenders and the Kenko set.

That's for 37 mm of Canon tubes vs 68 mm of Kenko Tubes of course, which may or may not matter to you.

I've always been happy with the Kenko tubes but I mainly use them on small lenses. I've had several Kenko TCs but I also have two Canon Extenders which I use on a heavy lens ( 300/2.8 ), and the rock-solid build quality of the Canons does make a difference there.

 

[Tanispyre]

I do like the Canon 12mm tube, the smaller tubes are useful for shorter focal length lenses, and only Canon makes a 12 mm, for more extension, I see no difference between a good set of Kenko Auto extension tubes, and the Canon ones. The Kenko set also allows more combinations of extension for various magnifications.

 

[wsheldon]

I do like the Canon 12mm tube, the smaller tubes are useful for shorter focal length lenses, and only Canon makes a 12 mm, for more extension, I see no difference between a good set of Kenko Auto extension tubes, and the Canon ones. The Kenko set also allows more combinations of extension for various magnifications.

That's not accurate. Kenko also makes a 12mm, and the automatic extension tube set for Canon (http://www.bhphotovideo.com/c/product/375102-REG/Kenko_AEXTUBEDGC_Auto_Extension_Tube_Set.html) comes with 12mm, 20mm and 36mm tubes that can be used individually or stacked.

Just bought a set of those and they're quite nice. Perhaps not as beefy as the Canon and don't mount quite as smoothly (but fine), but a good cost savings at $180 for up to 68mm in extension.