topic Re: extension tube question in EF & RF Lenses

extension tube question

DougFraser — Tue, 23 Feb 2021 17:20:17 GMT

I need to know the inside diameter of the Canon 12mm extension tube.

I want to use the extension tube between my 1.4X III teleconverter and my 100mm 2.8 L macro (which are otherwise non-compatible). I have read where people are using this combo successfully BUT the protruding portion of the converter will not fit inside my old set of Kenko extension tubes so I would like to know if it will fit with the Canon before buying the new extension tube.

I have the R5 and the focus stacking ability makes macro work even more fabulous so I want to take full advantage of the equipment I have.

Re: extension tube question

Waddizzle — Fri, 26 Feb 2021 08:35:54 GMT

".....I have read where people are using this combo successfully BUT the protruding portion of the converter will not fit inside my old set of Kenko extension tubes so I would like to know if it will fit...."

Somehow I doubt it. The exact dimension is probably irrelevant. If it fits a Canon mount, then another set of tubes will most likely have a similar size and fit. Or in your case, won't fit.

Maybe you should ask the people who seem to have success. But, before you do, I think you're chasing a something down a rabbit hole. I think that you need to better understand how the gear works. Let's forget about the claims of others for a moment.

Extension tubes work by decreasing the Minimum Focusing Distnce, which comes at the cost of a dramatic reduction in the Maximum Focusing Distance. In other words, using extension tubes means you lose the ability to focus to Inifinity, or across the average size room for that matter. A true macro lens already has a pretty short MFD.

MFD is measured from the image sensor, not the front of the lens. It is possible that you can shorten the MFD to the point that it is inside of the barrel of the lens! It happens to people al the time. We frequently get posts from people asking why can't they focus on anything when using extension tubes. The reason is because they have stacked too many and the focus plane is inside of the lens barrel.

Using extension tubes with a macro lens means your will rapidly approach the point of diminishing returns. The most likely outcome is that MFD will be reduced to the point that the lens is so close that ambient light will no longer be able to adequately light up your subject. The lens will cast a shadow over the subject, which may require you add special lighting gear.

Canon teleconverters are made to work with specific telephoto lenses. I do not think any macro lenses are included in the list of compatible lenses. An incompatible lens may cause the camera to display an error message. Nearly all of the compatible lenses have 300mm focal lengths, or longer. One notable exception are the 70-200 lenses.

If you're using a third party, budget teleconverter, then it may "work" with your macro lens, or at least seem to. the image quality of it is probably not on par with the Canon teleconverters, and the macro lens will only magnify those differences.

If you're still convinced that the setup should work, then I strongly suggest that you contact the people who claimed it works. I do not think it will work, and your experiences so far have proven that to be true.

Re: extension tube question

ebiggs1 — Fri, 26 Feb 2021 15:23:16 GMT

You know I am not a big fan of any adapter, tel-con or tubes.

I agree with all that is said above because sometimes the trouble you go through just to get them to work properly isn't worth it. The more you try to push adapters or extension tubes the more difficult it becomes until, like stated above, it won't work at all.

Re: extension tube question

DougFraser — Fri, 26 Feb 2021 17:22:27 GMT

Thanks for the reply and sorry you had to go to all the trouble of describing the effects of teleconverters and extension tubes - I am VERY familiar with the optics etc. I also should not have said "I read" about this setup. I did read about it but also saw it being used in an online tutorial given by a professional photographer so I know it can be done. But in the tutorial, you did not see the "brand" or "model" of the converter or extension tubes I wish to find out 🙂 And the tutorial is several years old so not easy to get a response to a question although I have sent one of course. When it comes to "diminishing returns" - I don't know if you have done much macro work but any increase in magnification can be welcome depending on the set-up and with the 100mm lens you do have a little room to work with. So I've done lots of macro work using extension tubes in combo with my macro lens. And when I feel a need to use an extension tube with my macro the last thing I am worried about is not being able to "focus across the room" 🙂 Of course "lens shadow" is something everyone is aware of if they have ever tried macro work - I use a nice macro ring flash and portable light sources, reflectors etc depending on the situation to get around that issue.
In terms of lens compatibility with the extension tubes - I think the only reason for the "problem" is the physical mismatch. I only know it works with the macro-extension combo because I've seen the video of this professional using it. It works beautifully with my 100-400 L II. Canon would have clearly had their engineers design a teleconverter for the "long lens user" market because that is certainly where the main demand is and why I have one. But the ability to combine with the macro allows for greater mag which is often what macro enthusiasts are "chasing" much of the time. Note that the inner diameter of extension tubes I already have not are perhaps just 1mm too narrow so a different model may very well be just big enough to fit so I am hopeful. Unfortunately, you can't go into most photography stores and try because so many of them don't stock extension tubes and I don't live anywhere near one of the very large camera store. I would note that "my experiences so far" are having a single brand of extension tubes - so I think it's fair to dig a little deeper than that before giving up 🙂
Thanks again for your detailed response - I really do appreciate it.

Re: extension tube question

FloridaDrafter — Sun, 28 Feb 2021 23:04:09 GMT

@DougFraser wrote:
I need to know the inside diameter of the Canon 12mm extension tube.

I want to use the extension tube between my 1.4X III teleconverter and my 100mm 2.8 L macro (which are otherwise non-compatible). I have read where people are using this combo successfully BUT the protruding portion of the converter will not fit inside my old set of Kenko extension tubes so I would like to know if it will fit with the Canon before buying the new extension tube.

I have the R5 and the focus stacking ability makes macro work even more fabulous so I want to take full advantage of the equipment I have.

I have the Canon EF 25 II extension tube and the Canon 1.4 III extender, so I just checked to see if it would fit. They attached together easily, but was very hard to take back apart, in fact, I got that sinking feeling when you know you messed up, but with a little patience and light pulling, it came apart. I wouldn't recomend this. It was like a Chinese Fingertrap 🙂

Newton

Re: extension tube question

DougFraser — Sun, 28 Feb 2021 23:34:24 GMT

yikes - a shame they went together easily then problematic to separate. Sorry for any stress that caused you. I haven't heard back from the pro that apparently uses this combo to see what models/brands he uses.

Re: extension tube question

FloridaDrafter — Mon, 01 Mar 2021 00:49:10 GMT

@DougFraser wrote:
yikes - a shame they went together easily then problematic to separate. Sorry for any stress that caused you. I haven't heard back from the pro that apparently uses this combo to see what models/brands he uses.

No problem brother. I shoot a lot of macro and have the 100mm L, so I was curious. Although I have the EF 25 II tube, I have never used it with the 100mm L macro lens. You never know, I may have cocked the devices when I was trying to disconnect them, but I don't think so. I just gently wiggled and twisted until it came apart.

Re: extension tube question

DougFraser — Mon, 01 Mar 2021 02:32:44 GMT

thanks. I guess one would certainly expect that if they do fit then putting them together and taking them apart would be equally facile. All canon products should have identical "mounts". So now I'm a bit torn. I got the 1.4X III to use with my 100-400 L II and I have done lots of macro with the 100 L so it just seemed like a nice bonus option - a little more magnification while maintaining the nice bit of distance to the subject.

Re: extension tube question

DougFraser — Sat, 06 Mar 2021 01:57:28 GMT

FYI - I did hear back from the pro that made the video where he was using the combo and it was a Canon 12mm extension tube coupled to the Canon 1.4X III so I guess it "can work" if you are careful. At least he uses it routinely. Now I just have to confirm that AF is still available because I would want to be able to use the focus bracketing setting of the R5 to take full advantage of the investment.

Re: extension tube question

Waddizzle — Sun, 07 Mar 2021 09:54:51 GMT

@DougFraser wrote:
FYI - I did hear back from the pro that made the video where he was using the combo and it was a Canon 12mm extension tube coupled to the Canon 1.4X III so I guess it "can work" if you are careful. At least he uses it routinely. Now I just have to confirm that AF is still available because I would want to be able to use the focus bracketing setting of the R5 to take full advantage of the investment.

I would be very surprised if that work around is compatible with the focus bracketing feature in some Canon cameras. I know the full User Guide lists a handful of compatible lenses. You just might be limited to shooting JPG, if it even works, at all.

Re: extension tube question

DougFraser — Sun, 07 Mar 2021 22:29:04 GMT

I don't know enough about the way lenses communicate using these devices. It just seems odd that they would be able to allow for AF control by the camera (which they seem to do with the 100-400) but not allow focus bracketing by the camera - isn't the "same kind" of instruction being sent to the lens? IE to adjust the focus. If anything - I would think the focus bracketing might be easier as all the camera has to do is send increments to the lens and change the focus until it reaches the "count" or infinity focus - whichever comes first. I guess I can just try it with my 100-400 in various combinations with the extension tube and converter 🙂 Something I haven't bothered with since I would not normally use my long lens with the feature.

Re: extension tube question

Waddizzle — Mon, 08 Mar 2021 17:29:38 GMT

@DougFraser wrote:
I don't know enough about the way lenses communicate using these devices. It just seems odd that they would be able to allow for AF control by the camera (which they seem to do with the 100-400) but not allow focus bracketing by the camera - isn't the "same kind" of instruction being sent to the lens? IE to adjust the focus. If anything - I would think the focus bracketing might be easier as all the camera has to do is send increments to the lens and change the focus until it reaches the "count" or infinity focus - whichever comes first. I guess I can just try it with my 100-400 in various combinations with the extension tube and converter 🙂 Something I haven't bothered with since I would not normally use my long lens with the feature.

The problem isn't the focusing. I never said anything about it focusing or nor focusing. The problem is on the back end, processing the images. You may be limited to processing JPGs in post, not in the camera.

Re: extension tube question

DougFraser — Mon, 08 Mar 2021 18:40:06 GMT

ok - I was unclear about what you were referring to - but in any event, the combination of extension tube and converter seems to work fine. The R5 will shoot in any file format (RAW, cRAW and or JPEG) while focus bracketing with both an extension tube and converter on my 100-400 so I can't honestly think of why a focus stacking program won't be able to work with those images any differently just because there is a converter in combination with an extension tube? Maybe DPP takes the lens information into account but that is not the case for all the main stacking programs available - they simply compare, process and combine images. I must say that focus stacking in my limited experience is a bit hit and miss at the best of times so it's not my primary reason for wanting this combo - but the camera's ability to do the focus bracketing certainly makes it more tempting.

Re: extension tube question

DougFraser — Mon, 08 Mar 2021 18:45:23 GMT

fyi - all this can be a bit frustrating because getting an answer from Canon can prove a bit challenging. The first and only response so far from them is that I would "lose" AF ability. But when I use a Kenko extension tube and the Canon 1.4X III converter on the 100-400 I retain full autofocus capability including the camera's ability to perform focus bracketing flawlessly so the Canon person got that aspect wrong. Unless the Kenko extension tube is more compatible than the Canon brand 🙂

Re: extension tube question

jrhoffman75 — Tue, 09 Mar 2021 00:50:28 GMT

From the DPP manual:

Re: extension tube question

DougFraser — Tue, 09 Mar 2021 01:01:27 GMT

Thanks for posting John,

As noted in the manual there are no barriers to using DPP for focus stacking with images from the R5 regardless of the lens (clearly some are recommended) and no mention of any objection to using extension tubes or extenders. I have ordered the Canon extension tube so I can try the extender with my macro 100L but in the meantime I will do a little stacking with the lens and kenko extension tube alone as well as with the 100-400L and extender combo. I will also compare the DPP with PS to see which generates better results. It would be nice to just use lightroom and PS rather than going the DPP route as I currently don't use DPP for image processing now. Have you used DPP for stacking?

Re: extension tube question

FloridaDrafter — Tue, 09 Mar 2021 03:00:50 GMT

@DougFraser wrote:
Have you used DPP for stacking?

I'll jump in here and say that I have. I've been focus stacking for years but used dedicated software made by Helicon. These two were shot with Helicon Remote and stacked in DPP. Obviously, DPP isn't as robust as helicon, but it does a fair job of stacking. I'm not impressed by Canons in camera stacking, although it does a fair job. BTW, I've only tried it with the R6 so the R5 may do better.

5D mark IV and 100mm f/2.8 IS USM L macro. Stacked from Raw.

7D mark II and 100mm f/2.8 IS USM L macro. Stacked from JPeG as a demo to show jpg can be used. The original Tiff files were much much better.

Re: extension tube question

FloridaDrafter — Tue, 09 Mar 2021 04:08:20 GMT

To expand my comments a bit. Focus Stacking isn't perfect, regardless of what software you use, and portions of your stack will not be sharp and sometimes just blurry. To remedy this, you have to do some post processing. If you get a blemished area, you have to pick one of the images in the stack, that is in focus, and you "brush" or "clone" the in focus area to the composit. Helicon Focus has a side by side touchup screen that is really easy to use and works well to repair your composit. DPP4 has this, but it is very awkward to use. DPP shows all the shots in your stack as thumbnails with the composit in a pane, which makes it very hard to select the "in focus" portion of the stack to use as clone stock. It does pop up in a side by side when clicked, but Helicon displays the clone stock as you roll over it. DPP is slow to process, and I run a modest i7 6 core Gen 10, NVMe M.2 SSD (2TB), 32GB RAM, 17" laptop (Dell XPS)

Now, Helicon Remote lets you pick a "Point A" or beginng point, then select a "Point B" to end the stack. You can control the mumber of shots either by f/stop or specify a number of shots. I leave it to auto and just set my f/stops and it calculates shots depending on the calculation method I've selected, overlap, tri-angle size, etc. All of this is done in live view, and HR looks very similar to EOS 3 Utility. I use a 10' USB cable to connect.

I guess I'm spoiled, so I want more than selecting a starting point and setting a shot count then strugling to fix or touchup my stacks. Don't get me wrong, DPP does a really good job but you have to do more pre shot planning so you don't have to do so much editing.

Newton

Re: extension tube question

DougFraser — Tue, 09 Mar 2021 04:59:59 GMT

Thanks! great info.

I don't suppose you have tried PS auto-align with auto-blend as a stacking option?

I have just got started with this R5 and do like the fact that it takes the photos for me and very rapidly compared to what I would have attempted by hand in the past. But as you note - Helicon remote is a better option upfront. But it sounds like it's not portable? Is it something you can do on a hike with wildflowers - ie can HR be put on a smartphone or must your camera be connected to your laptop? I have been fiddling around a little bit with DPP and it seems excruciatingly slow but I was asking it to stack 50 images.
Beautiful photos by the way - how many images were stacked in those photos?

Re: extension tube question

jrhoffman75 — Tue, 09 Mar 2021 11:22:53 GMT

@DougFraser wrote:
Thanks! great info.
I don't suppose you have tried PS auto-align with auto-blend as a stacking option?
I have just got started with this R5 and do like the fact that it takes the photos for me and very rapidly compared to what I would have attempted by hand in the past. But as you note - Helicon remote is a better option upfront. But it sounds like it's not portable? Is it something you can do on a hike with wildflowers - ie can HR be put on a smartphone or must your camera be connected to your laptop? I have been fiddling around a little bit with DPP and it seems excruciatingly slow but I was asking it to stack 50 images.
Beautiful photos by the way - how many images were stacked in those photos?

Helicon does have a device called the Focus Bracketing Tube (FBT). It interfaces with a smartphone. You send contol information from the smartphone to the FBT and then the FBT controls lens focus as you shoot.