# Advice: extension tubes Macro



## candyman (Aug 12, 2013)

I would like to extend my canon 100L Macro with extension tubes.
I have a few options but like to hear what option you would choose and why:
1. Canon 5D MK III + 100L+canon 12mm+canon 25mm
2. Canon 5D MK III + 100L+kenko 12mm+kenko 20mm+kenko 36mm
3. Canon 7D + 100L+canon 12mm+canon 25mm
4. Canon 7D + 100L+kenko 12mm+kenko 20mm+kenko 36mm
Of course I can use extension tubes also single instead of stacked

Price Canon vs Kenko tubeset is similar: around 200 euro

Thanks


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## neuroanatomist (Aug 12, 2013)

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).


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## jdramirez (Aug 12, 2013)

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?


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## jdramirez (Aug 12, 2013)

neuroanatomist said:


> 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).



I was thinking the same thing about the air, but I did get some extension tubes that wouldn't allow me to change the aperture... so if that was an issue regarding the consistency of the connection.


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## candyman (Aug 12, 2013)

neuroanatomist said:


> 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).


See, that was what I was thinking. Why buying Canon? Build quality. But not for a relative light lens as 100L. Thanks


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## candyman (Aug 12, 2013)

jdramirez said:


> 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


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## schill (Aug 12, 2013)

candyman said:


> jdramirez said:
> 
> 
> > 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'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.


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## lion rock (Aug 12, 2013)

I used all three Kenko tubes and the 100mmL IS to take the attached picture. The distance was under three inches.
Focusing is not terribly easy, just takes a steady tripod and a bit of patience.
-r



candyman said:


> jdramirez said:
> 
> 
> > 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?
> ...


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## jdramirez (Aug 12, 2013)

lion rock said:


> I used all three Kenko tubes and the 100mmL IS to take the attached picture. The distance was under three inches.
> Focusing is not terribly easy, just takes a steady tripod and a bit of patience.
> -r
> 
> ...



what exactly am I looking at?


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## lol (Aug 12, 2013)

That image looks like a butterfly wing to me.

Be aware of the difference between minimum focus distance, and working distance. MFD is from sensor to subject. Working distance is from lens front to subject. Do you care about either anyway if you can get the magnification?

Personally if I need a small boost in magnification I'd reach for a teleconverter first. A 1.4x wouldn't usually impact the quality significantly and you don't have to worry about limited focus ranges as you do with extension tubes or "close up filters".


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## candyman (Aug 12, 2013)

jdramirez said:


> lion rock said:
> 
> 
> > I used all three Kenko tubes and the 100mmL IS to take the attached picture. The distance was under three inches.
> ...




Middle East excavation site in progress. 
What I do is I take photographs to point the exact position of artifacts in relation to eachother and the site (don't necessarily need tubes for that). 
I further take closeup photographs of artifacts that are scuffed, broken - likes pieces of a mosaic floor that look the same - in order to get clues for 'puzzling'. Pieces are like 1 cm and very often part of floors of 3 square meter and larger


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## schill (Aug 12, 2013)

lol said:


> That image looks like a butterfly wing to me.
> 
> Be aware of the difference between minimum focus distance, and working distance. MFD is from sensor to subject. Working distance is from lens front to subject. Do you care about either anyway if you can get the magnification?
> 
> Personally if I need a small boost in magnification I'd reach for a teleconverter first. A 1.4x wouldn't usually impact the quality significantly and you don't have to worry about limited focus ranges as you do with extension tubes or "close up filters".



Just a reminder that the Canon teleconverters will not work with the macro lenses.


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## Mt Spokane Photography (Aug 12, 2013)

candyman said:


> I would like to extend my canon 100L Macro with extension tubes.
> I have a few options but like to hear what option you would choose and why:
> 1. Canon 5D MK III + 100L+canon 12mm+canon 25mm
> 2. Canon 5D MK III + 100L+kenko 12mm+kenko 20mm+kenko 36mm
> ...


Kenko is excellent, get a 3 piece set and you will be fine. I have a cheap plastic set that works just fine for smaller lenses. I've had Canon, Kenko, and now a cheapie plastic set, all worked equally well for me. I would not buy the cheap set, they came with a used camera and since I use them maybe once a year, I sold the Canon and Kenko tubes and kept the cheap ones.
You want to be sure its the type of set that has the electrical contacts, there are low cost EF tubes without contacts, and then its a issue to focus or set the aperture.

The electrical contacts go straight thru to the lens contacts, no electronics. This means the camera will not know the tubes are there, its like you are hooked directly to the lens.


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## photonius (Aug 12, 2013)

schill said:


> candyman said:
> 
> 
> > jdramirez said:
> ...



The minimal working distance will slowly decrease, but after around 1:1 magnification, the minimal focus distance will increase again due to the increased distance of the extension tubes. Think about the single thin lens formula (see e.g., http://photonius.wikispaces.com/Close-up+%26+Macro), as the object gets closer and closer to the camera (lens), the lens moves further and further from the sensor (i.e. projected image). At 1:1 a 50mm lens is 100mm from the sensor and 100mm from the object. Increasing magnification further, the situation now simply reverses, i.e. the lens moves further and further away from the senor, while the object creeps closer to the lens. Once the object is 50mm from the lens (the focal length), the image (sensor) has to be at infinity from the lens.


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## jdramirez (Aug 12, 2013)

photonius said:


> schill said:
> 
> 
> > candyman said:
> ...



do we ever get to divide by pi?


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## 2n10 (Aug 12, 2013)

jdramirez said:


> photonius said:
> 
> 
> > schill said:
> ...



ROFLMAO.


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## danski0224 (Aug 12, 2013)

schill said:


> Just a reminder that the Canon teleconverters will not work with the macro lenses.



The 100mm macro may not work with a Canon teleconverter, but the 180mm macro does.


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## drjlo (Aug 12, 2013)

"Vivitar" (same as "Pro Optic") extension tube set (13, 21, and 31 mm set) is built like a tank and has worked perfectly,all for $62.90. No need to pay premium for Canon air IME.

http://www.adorama.com/VVEXTC.html


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## AudioGlenn (Aug 12, 2013)

I use the Kenko tubes. (~$150 from eBay I believe). They work great.


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## Mt Spokane Photography (Aug 13, 2013)

drjlo said:


> "Vivitar" (same as "Pro Optic") extension tube set (13, 21, and 31 mm set) is built like a tank and has worked perfectly,all for $62.90. No need to pay premium for Canon air IME.
> 
> http://www.adorama.com/VVEXTC.html


Same cheap plastic ones as I have. They work fine for occasional use, but for someone using them as part of his job like the OP is, I'd go for metal. They do have a weakness, the mounts spring open with a larger lens on them, and that makes the top and bottom go out of focus, since the lens basically tilts.


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## rpt (Aug 13, 2013)

danski0224 said:


> schill said:
> 
> 
> > Just a reminder that the Canon teleconverters will not work with the macro lenses.
> ...


If you add a 12mm macro extension tube it will work.


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## monkeyhand (Aug 16, 2013)

I bought an old pair of used Canon ones for pretty cheap. If you go with the older set they only work with EF lenses and not EF-S lenses but I saved about 70 bucks.


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## danski0224 (Sep 1, 2013)

rpt said:


> If you add a 12mm macro extension tube it will work.



I tried a Kenko 12mm tube and a Canon 1.4xIII converter on a 5DIII.

The AF seems to work if the focus point is more than about 18" away.

If I attempt AF within the yellow Macro range indicated on the lens, the AF is jittery and won't lock on. Manual AF works as well as my eyes do 

Is this typical for extension tube use?


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## makuroske (Sep 2, 2013)

I purchased the kenko extension tube set last year and have been really happy with them despite:

more ISO noise
more light required to get proper exposure 
more sensor dust
losing infinity focus

You might also want to look into a macro focusing slider. 

Here are a few pics i took with the kenko tubes and the 5D II + canon 100mm 2.8 USM macro lens.

1. Japanese Hawk Moth Caterpillar (スズメガ)
2. Japanese Giant Killer Hornet (オオスズメバチ)


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## rpt (Sep 2, 2013)

makuroske said:


> I purchased the kenko extension tube set last year and have been really happy with them despite:
> 
> more ISO noise


ETTR or manual exposure.



> more light required to get proper exposure


Yup! Light 101 - the intensity of light is inversely proportional to the square of the distance... So expect that to happen.



> more sensor dust


Don't know about that...



> losing infinity focus


Yup! So only works for macro work...



> You might also want to look into a macro focusing slider.


+10000! You may want one that moves along two axis. If you ask neuro he'd say get the RRS one...



> Here are a few pics i took with the kenko tubes and the 5D II + canon 100mm 2.8 USM macro lens.
> 
> 1. Japanese Hawk Moth Caterpillar (スズメガ)
> 2. Japanese Giant Killer Hornet (オオスズメバチ)


Lovely!


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## Eldar (Sep 2, 2013)

I got the Canon versions for the same reason as Neuro, for use with my 600mm, but from what I hear and read, the Kenko will work just as well. Giving the short DOF, I strongly recommend a macro focusing slider and the best I have found is the Really Right Stuff. It is very high quality, very smooth. For really close ups I use the Novoflex bellow. But then your mobility become quite snailish.


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## danski0224 (Sep 2, 2013)

Eldar said:


> I got the Canon versions for the same reason as Neuro, for use with my 600mm, but from what I hear and read, the Kenko will work just as well. Giving the short DOF, I strongly recommend a macro focusing slider and the best I have found is the Really Right Stuff. It is very high quality, very smooth. For really close ups I use the Novoflex bellow. But then your mobility become quite snailish.



Any thoughts on the Novoflex slider?


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## Camerajah (Sep 2, 2013)

One should get a set of close up lens as well extension tube,close up lens normally come in sets of 3


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## Eldar (Sep 3, 2013)

danski0224 said:


> Eldar said:
> 
> 
> > I got the Canon versions for the same reason as Neuro, for use with my 600mm, but from what I hear and read, the Kenko will work just as well. Giving the short DOF, I strongly recommend a macro focusing slider and the best I have found is the Really Right Stuff. It is very high quality, very smooth. For really close ups I use the Novoflex bellow. But then your mobility become quite snailish.
> ...



Novoflex in general delivers very high quality products. I have not used their slider, but I am sure it´s a very good alternative. It also has some expansion options which could be of interest if this is your main area of photography. To me macro is a fun add-on in the absence of birds and wildlife. 

I have been very happy with the RRS heads I have for my tripods and monopod and the solid and simplistic design of their slider appealed to me. The micro focus control you get with the lead screw (1.25mm pr. 360 degree turn) works very well. It is also $200 cheaper than the Novoflex.


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## alexturton (Sep 3, 2013)

get the kenko tubes. They are relative cheap and give a wide range of extension stacking options


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## rpt (Sep 3, 2013)

alexturton said:


> get the kenko tubes. They are relative cheap and give a wide range of extension stacking options


+1 on that!


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## photonius (Sep 3, 2013)

Camerajah said:


> One should get a set of close up lens as well extension tube,close up lens normally come in sets of 3



If you talk about the cheap single lens close-up sets, no, they are not recommended. They deliver poor IQ at higher magnifications.
Achromat doublet close-up lenses are much better, see also samples here:
http://photonius.wikispaces.com/Close-up+%26+Macro

Indeed, for an archeological site in the MidEast with presumably lots of dust, a close-up lens on the front may be better than adding/removing extension tubes (the dust issue mentioned). 

A set of Raynox lenses (4.8 and 8 diopters) should give good extra magnification on the 100mm macro, and it should have a relatively easy snap-on holder.


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## eli452 (Sep 4, 2013)

Does anyone have tried connecting the Kenko extension tube to TS-E lens (24 mk II specificly)?
Kenko specify "compatible with Canon EF and EFS lenses"
the Canon original (mk II) state "Compatible with digital EF-S lenses, as well as EF and TS-E lenses"
(the quote is from the B&H site

Eli


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## neuroanatomist (Sep 4, 2013)

eli452 said:


> Does anyone have tried connecting the Kenko extension tube to TS-E lens (24 mk II specificly)?
> Kenko specify "compatible with Canon EF and EFS lenses"
> the Canon original (mk II) state "Compatible with digital EF-S lenses, as well as EF and TS-E lenses"
> (the quote is from the B&H site



Interesting that B&H states that, because I do not recall Canon having stated that the extenders are compatible with TS-E lenses. In fact, while they are physically compatible, they are not fully electronically compatible in that the TC changes the f/number, and that is not correctly reported in the EXIF (the TS-E lenses lack the additional pins necessary for communication with the TC). 

Although I have not tried it, there is no reason a Kenko TC shouldn't work with the TS-E lenses.


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## eli452 (Sep 4, 2013)

The canon page for the TS-E 24mm f/3.5L II names the Extension Tube EF 12 II as an "Supplies & Accessories" option.
http://www.usa.canon.com/cusa/consumer/products/cameras/ef_lens_lineup/ts_e_24mm_f_3_5l_ii#SuppliesAndAccessories
and the "compatible products" link names all but the 17mm TS-E lens.


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## surapon (Sep 4, 2013)

neuroanatomist said:


> eli452 said:
> 
> 
> > Does anyone have tried connecting the Kenko extension tube to TS-E lens (24 mk II specificly)?
> ...




Dear Teacher, Mr. Neuroanatomist.
I just read my Manual Book for my TS-E 24 mm F/ 3.5 L MK II =
"13. Extension Tubes( Eng-19)
For TS-E 24 mm F 3.5 L II . You can attach extension tube EF 12 II for magnified shot-----The extension tube EF 12 II cannot used with TS-E 17 mm F/4 L.
Although Extension Tube EF 25 II can be attached on TS-E 24 mm F/ 3.5 L II. It is not recommended because the Lens-to-subject distant will be very short."

Surapon


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## neuroanatomist (Sep 4, 2013)

eli452 said:


> The canon page for the TS-E 24mm f/3.5L II names the Extension Tube EF 12 II as an "Supplies & Accessories" option.
> http://www.usa.canon.com/cusa/consumer/products/cameras/ef_lens_lineup/ts_e_24mm_f_3_5l_ii#SuppliesAndAccessories
> and the "compatible products" link names all but the 17mm TS-E lens.



My apologies - you wrote "Kenko extension tube" and I read Kenko extender (aka teleconverter). Sorry for the confusion!

Pretty much any extension tube is physically compatible with pretty much any lens - an extension tube is just a hollow tube filled with air, and most have pass-through electrical contacts. 

The compatibility issue with tubes comes from the fact that they increase magnification by decreasing the minimum focus distance, which also means a decreased working distance (distance from front element to subject). The added magnification is the ratio of focal length / tube length. With a longer tube on a shorter lens, it's possible that the MFD is reduced to the point where it's actually _behind_ the front element, meaning you can't focus on the subject at all. That's why you can't use the EF 12 tube with the TS-E 17mm.

Since the Kenko tubes come as a set, you'll be able to use the shorter one(s) with the TS-E 24mm, but not the 36mm tube, and not with them stacked as you can with longer lenses.


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## Skatol (Aug 20, 2014)

neuroanatomist said:


> 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.


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## mackguyver (Aug 20, 2014)

neuroanatomist said:


> 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).


The 180L isn't exactly light...but then again, it lets you use extenders, which along with the included tripod collar is 90% of why I chose it over the 100L. 

As for your question, it would help to know what you plan to shoot and where - studio or outdoors?

For the 100L, it looks like the 25mm tube gets you to 1.37x, similar to what I get with my 180 + 1.4x, which is significant enough to be worth the investment. I'd go with the 5DIII unless you've got a lot of light as you'll generally be stuck using ISO 1600+ even in good natural light at that magnification. Macro rails are great and I use a RRS Precision Plus Package pano set with pretty good results, but the dedicated RRS or Novoflex rails are much better. They are also much more expensive 

Also, that's correct about the TS-E + extenders & tubes. They work, but are not included in the EXIF and in certain combinations can throw off exposure unless LiveView is used.


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## tolusina (Aug 21, 2014)

candyman said:


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



From
http://www.cambridgeincolour.com/tutorials/macro-extension-tubes-closeup.htm

"_An extension tube increases lens magnification by an amount equal to the extension distance divided by the lens focal length. For example, adding a 25 mm extension tube to a 50 mm lens will give a magnification gain of 0.5X. Therefore, if the lens's original magnification was 0.15X, then the new magnification will be 0.15X+0.5X=0.65X. The closest focusing distance will also decrease to ~210 mm_."

and

"_Note how extension tubes provide minimal magnification when used with telephoto lenses — which is unfortunately their main weakness_."

From
http://www.usa.canon.com/cusa/consumer/products/cameras/ef_lens_lineup/ef_100mm_f_2_8l_macro_is_usm#Specifications

"_*Closest Focusing Distance*
0.99 ft./0.3m (maximum close-up magnification: 1x)_"

So, a full set of Kenko tubes adding up to 68mm will increase the magnification of your 100L macro only from 1.0 to 1.68.

You'll have a very shallow depth of field which focus stacking can overcome. 
To focus stack you'll need a sturdy tripod and either a macro rail or tethered focusing control, or manual focus steps as you determine by eye, preferably in live view.
If you're shooting artifacts in situ rather than on a work bench or table, your tripod will have to be configured to mount the camera very low to the ground such as is possible with an inverted post. Manual focusing with the ground level mounted camera will be awkward and uncomfortable at best, a total failure at the worst. 
I suggest tethered control.

If dust can or will be a factor, that may compromise effectiveness and longevity of a focusing rail will all its exposed components, same for a bellows.

I like Helicon Focus for processing the stacked frames.

The Canon MP-E 65mm f/2.8 1-5x Macro Photo lens magnifies between 1X and 5X but must be focused manually which rules it out of tethered focus control is desired. Might be just what you seek if you'll manually focus (and stack) while live viewing tethered.


There's a thread here, "_first attempts at macro stacking, let's see some stuff. (beginners only please)_"




.


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## neuroanatomist (Aug 21, 2014)

Skatol said:


> neuroanatomist said:
> 
> 
> > 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).
> ...



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


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## Skatol (Aug 21, 2014)

neuroanatomist said:


> Skatol said:
> 
> 
> > neuroanatomist said:
> ...


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


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## mackguyver (Aug 21, 2014)

tolusina said:


> candyman said:
> 
> 
> > ....Middle East excavation site in progress.......
> ...


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## Mt Spokane Photography (Aug 21, 2014)

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.


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## Jack Douglas (Aug 21, 2014)

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


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## Sabaki (Aug 21, 2014)

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.


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## Eldar (Aug 21, 2014)

Sabaki said:


> 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.


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## Skatol (Aug 21, 2014)

Jack Douglas said:


> 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.
> 
> ...


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.


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## Skatol (Aug 21, 2014)

Sabaki said:


> 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.


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## NancyP (Aug 23, 2014)

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).


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## neuroanatomist (Aug 23, 2014)

NancyP said:


> 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.


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## mackguyver (Aug 25, 2014)

neuroanatomist said:


> NancyP said:
> 
> 
> > 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).
> ...


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).


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## AcutancePhotography (Aug 25, 2014)

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.


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## mukul (Aug 25, 2014)

schill said:


> candyman said:
> 
> 
> > jdramirez said:
> ...



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


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## Steve Balcombe (Aug 25, 2014)

Skatol said:



> 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.


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## Tanispyre (Aug 25, 2014)

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.


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## wsheldon (Aug 25, 2014)

Tanispyre said:


> 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.


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