100mm Macro lens w/Extension Tubes?

I was wondering if extension tubes will make a difference on a 100mm macro lens. What I'm looking for is to shoot close-ups of insects and bugs. I am shooting with a Canon 5d3 & Sigma 105mm. Never used the extension tubes before, so I'd like to find out if they really do make a difference, and to what extent?

no it doesnt

Here is an idea of what tubes can add as far as magnification. First three are the 100L last one is with a full set of tubes (68mm).

IMAGE LINK: http://www.flickr.com …s/adammrugacz/8​621034156/

SeattleSpeedster wrote in post #16192134
no it doesnt

Yeah, none at all. lol

Here is a post from another forum I put together showing on a non macro lens how things get changed. They react differently on macro lenses but you can get the idea.

I have never seen a series of shots the show how the Kenko tubes (or any tubes for that matter) change the MFD and magnification ratio so I put a quick one together. I made the mistake of having the lens at an angle so half the logo (or more) is OOF in these but it also shows how thin the DOF gets when you start stacking on tubes.

All shot at or very close to Minimum Focusing Distance

Bare 85 mm

HTTP response: 404 | MIME changed to 'image/gif' | Byte size: ZERO

85mm + 12mm Tube (0.14X Magnification)

HTTP response: 404 | MIME changed to 'image/gif' | Byte size: ZERO

85mm + 12 & 20 mm Tubes (0.37X Magnification)

HTTP response: 404 | MIME changed to 'image/gif' | Byte size: ZERO

85mm + 12, 20 & 36 mm Tubes (0.8X Magnification)

HTTP response: 404 | MIME changed to 'image/gif' | Byte size: ZERO

Got it! So you don't have to change the distance to subject, but they will magnify the subject instead? So for insects, my distance to subject could remain unchanged?

bikfoto wrote in post #16192174
Got it! So you don't have to change the distance to subject, but they will magnify the subject instead? So for insects, my distance to subject could remain unchanged?

Nope, subject distance assuming the same focal length and focus setting (set to MFD) will decrease with each tube you add to the mix.

To move further away you need a longer focal length (ex. sigma 150mm macro or Canon 180mm macro) which give you a bit more working distance.

bikfoto wrote in post #16192174
Got it! So you don't have to change the distance to subject, but they will magnify the subject instead? So for insects, my distance to subject could remain unchanged?

NO, extension tubes only 'move the optics farther from the focal plane', they have no direct optical effect in terms of alteration of FL. Because the optics move farther away, the image circle gets larger, and the frame captures a smaller section of the total image circle...effectively the magnification of the subject is greater as a result.

As you increase magnification, the closer you get to the subject.

bikfoto wrote in post #16192120
I was wondering if extension tubes will make a difference on a 100mm macro lens. What I'm looking for is to shoot close-ups of insects and bugs. I am shooting with a Canon 5d3 & Sigma 105mm. Never used the extension tubes before, so I'd like to find out if they really do make a difference, and to what extent?

Yes, absolutely! Get the latest Kenko set.

bikfoto wrote in post #16192174
Got it! So you don't have to change the distance to subject, but they will magnify the subject instead? So for insects, my distance to subject could remain unchanged?

If this is what you want, then a teleconverter is what you need. A 1.4x TC will give you 1.4:1 magnification ratio, without changing distance.

An extension tube will not make anything bigger in the frame, what it allows you to do is move in closer which will yield higher magnification.
An extender(converter) will give you a greater magnification for the same working distance or the same magnification at a greater distance. Hope this makes sense!

Most Macro lenses will not accept many types of extender so I modified one of my extension tubes (the one on the left), with a craft knife, so I can now use my Canon Extenders on my 100 F2.8 Macro.

If you are into macro at all, extension tubes are a tremendously fun buy for the money as you can use them on non-macro lenses as well as your macro lens. I highly recommend them as a super-affordable upgrade for your kit.

If you really want to get close investigate a reverse mount adapter. Manual mode only but results can be larger than life size.

There are many ways to do macro photography...

You can add extension tubes to your macro lens to get greater than 1:1 magnification. I don't have the exact numbers for a Sigma 105mm macro lens, but adding a 12mm tube to a Canon 100/2.8 USM macro lens allows it to go up to 1.19:1 magnification. Adding a 25mm extension tube increases it to 1.39:1 magnification. I'd estimate with a 36mm extension tube, such as is included in the Kenko set, the 100/2.8 lens should be pretty close to 2:1 magnification. Though it won't be exactly the same, you should see similar results with a Sigma 105mm.

Yes, increasing magnification with extension tubes also will move you closer to the subject, reducing working distance. You can expect that the working distance you presently have at 1:1 would be approx. cut in half if you extend the lens enough to do 2:1 magnification. (This is just an estimate. It will actually be more than cut in half, because focusing distance is measured from the film/sensor plane of the camera and when you add an extension behind a lens, the lens + extension is physically longer than the lens alone, so will be taking up more of this distance.)

There is also light fall-off that occurs whenever you use an extension tube. Light weakens exponentially over distances. So with a lot of extension there will be a significant reduction in light reaching the camera's sensor. This won't matter if you are using the camera's internal metering system to calculate exposure (it compensates for the light fall-off). It also won't matter if using ETTL or TTL controlled flash. It only matters if calculating ambient exposure manually or using manual flash.

In order to increase magnification, but keep working distance about the same, John is correct. You'll need to use a teleconverter, instead. This adds optics behind the lens to actually change it's focal length, increasing magnification along with it. A 1.4X teleconverter would make a 100mm lens into an effective 140mm (with 1.4:1 magnification possible) and a 2X teleconverter would make the same 100mm lens into an effective 200mm (with 2X or 2:1 or twice life size mag possible).

Adding optics behind a lens will always reduce the light passing through and cost some image quality. The stronger the teleconverter (which Canon somewhat confusingly calls "Extenders"), the more light and quality is lost. A 1.4X "costs" a stop of light (making a 100/2.8 into an effective 140/4). And a 2X TC "costs" two stops (making that 100/2.8 into an effective 200/5.6). How much image quality is degraded depends upon a number of variables, making it hard to predict. You almost have to experiment with different combinations, to see if the loss is acceptible to you or not.

And Canon's teleconverters have a protruding front element, that prevents them from being used with a lot of shorter focal lengths. Canon cites their Extenders as usable with their 135mm and longer primes, and the 70-200mm and 100-400mm zooms. I also know that the Extenders can be used with the 90mm TS-E, but am not sure about the shorter TS-E lenses.

It is possible to use both... a 12mm extension tube and one of the Canon teleconverters together, to get around this physical limitation. Set up this way, the lens isn't going to be able to focus to infinity, but shootin' macro that really isn't a concern anyway.

You also can get third party teleconverters that do not have the protruding front element, so will be able to mount on more Canon or Canon-mount lenses. Some of them are quite good. Sigma makes both 1.4X and 2X in Canon mount and might work well with a Sigma lens (I haven't used them so can't say about IQ). The Kenko 1.4X also are considered quite good. Their latest 1.4X "MC-4" DGX - which is a less expensive model - is surprisingly good... Both their higher-end "Pro 300" DG and DGX 1.4X are considered very close to the quality of the Canon.

Due to lower light being transmitted and the extra electronic connections added by either extension tubes or teleconverters, expect AF to slow down and be more inclined to hunt in difficult lighting.

Yes, you can reverse-mount a lens to get higher magnification. Often a 50mm or short tele is best used for this. One drawback of doing this with modern Canon gear is loss of control over the lens' aperture. You can't stop it down via the controls on the camera (there is a way, but it involves un-reverse-mounting the lens, mounting it normally, dialing in the aperture you want, pressing and holding DOF preview while unmounting the lens, re-reverse-mounting it, then taking your shot... repeat any time you want to change the aperture... ugh!). An easier approach is to use a vintage lens with a manual aperture control ring, adapted for use on modern EOS.

Another trick is to reverse-stack two lenses. Here a shorter focal length is reversed, then attached to the front of a longer focal length. The reversed lens acts as sort of a macro diopter. For example, a 28, 35 or 50mm lens might be reverse mounted on the front of a 100 to 135mm lens. Doing this, the main lens still offers AF and aperture control, and there is no need to stop down the aperture of the reversed lens. The tricky part is matching up a short lens with similar diameter to the front of the main lens you'll be using for this purpose. The reversed lens needs to be close to the same or larger in diameter (making it difficult, for example, to do with the Canon 135/2 which has a 72mm filter thread... few 28 to 50mm lenses have that size filter thread or larger). There are reversing rings, male-threaded on both sides, sold for just this purpose.

You also can add a diopter to the front of a lens, just like a filter but to increase magnification. Canon offers the 250D and 500D in various diameters. (Note: the 250D is actually the stronger of the two and is designed for lenses 135mm and shorter. The 500D is designed for lenses 70mm and longer, if memory serves.) Nikon, Zeiss, B+W and others have offered high quality diopters in a variety of strengths. With all these, there's some loss of image quality due to adding optics.... often not multi-coated... to the front of the lens. They also are limited in use to lenses with the same filter thread size... and rather pricey. (Forget about the cheap "macro filter" sets you might find online and in camera stores... they are optically horrible and trach your image quality).

Or, pick up a Canon MP-E 65mm... It's an ultra high magnification macro lens. It can't shoot infinity at all. In fact it starts out at 1:1, where most macro lenses stop, and goes up to 5:1 magnification. This lens extends in length a great deal as it's focused to higher magnifications, resulting in light fall-off within the lens and effectively smaller apertures at higher magnificatioins. Plus it is manual focus only. But it's got high enough magnification to fill a FF camera's viewfinder with a grain of rice.

At higher magnifications, figure on using a tripod. First, even the slightest movement of camera or lens if greatly magnified. Plus it's hard to get enough depth of field, so smaller apertures may be necessary, which in turn means longer shutter speeds (and/or higher ISOs), making it even harder to steady a shot.

Alternatively, add light with a flash. It doesn't need to be a macro-specific flash. A single Speedlite... perhaps with a diffuser of some sort (I use a couple layers of white gauze bandage held on with a rubber band), connected with an off-camera shoe cord and handheld or on a special bracket... can work surprisingly well. Relative to a tiny subject, it's sort of like a giant softbox in the sky. You can use a reflector for fill, if necessary.

Or, there are macro flashes. I use the Canon MT 24EX Twinlite for up to 1:1 or maybe a little beyond. I use a special bracket for the Twinlite, that allows for more flexibility positioning the flash heads. At higher magnifications, I use the MR 14RX Ringlite (I just don't care for ring flashes at lower magnifications... it looks sort of flat and "clinical" to me).

https://photography-on-the.net/forum/showthre​ad.php?t=578274

i use a full set of tubes, and a 1.4TC on occasion...it's much easier than reversing a lens on the end

amfoto1 wrote in post #16194359
There are many ways to do macro photography...

You can add extension tubes to your macro lens to get greater than 1:1 magnification. I don't have the exact numbers for a Sigma 105mm macro lens, but adding a 12mm tube to a Canon 100/2.8 USM macro lens allows it to go up to 1.19:1 magnification. Adding a 25mm extension tube increases it to 1.39:1 magnification. I'd estimate with a 36mm extension tube, such as is included in the Kenko set, the 100/2.8 lens should be pretty close to 2:1 magnification. Though it won't be exactly the same, you should see similar results with a Sigma 105mm.

Yes, increasing magnification with extension tubes also will move you closer to the subject, reducing working distance. You can expect that the working distance you presently have at 1:1 would be approx. cut in half if you extend the lens enough to do 2:1 magnification. (This is just an estimate. It will actually be more than cut in half, because focusing distance is measured from the film/sensor plane of the camera and when you add an extension behind a lens, the lens + extension is physically longer than the lens alone, so will be taking up more of this distance.)

There is also light fall-off that occurs whenever you use an extension tube. Light weakens exponentially over distances. So with a lot of extension there will be a significant reduction in light reaching the camera's sensor. This won't matter if you are using the camera's internal metering system to calculate exposure (it compensates for the light fall-off). It also won't matter if using ETTL or TTL controlled flash. It only matters if calculating ambient exposure manually or using manual flash.

In order to increase magnification, but keep working distance about the same, John is correct. You'll need to use a teleconverter, instead. This adds optics behind the lens to actually change it's focal length, increasing magnification along with it. A 1.4X teleconverter would make a 100mm lens into an effective 140mm (with 1.4:1 magnification possible) and a 2X teleconverter would make the same 100mm lens into an effective 200mm (with 2X or 2:1 or twice life size mag possible).

Adding optics behind a lens will always reduce the light passing through and cost some image quality. The stronger the teleconverter (which Canon somewhat confusingly calls "Extenders"), the more light and quality is lost. A 1.4X "costs" a stop of light (making a 100/2.8 into an effective 140/4). And a 2X TC "costs" two stops (making that 100/2.8 into an effective 200/5.6). How much image quality is degraded depends upon a number of variables, making it hard to predict. You almost have to experiment with different combinations, to see if the loss is acceptible to you or not.

And Canon's teleconverters have a protruding front element, that prevents them from being used with a lot of shorter focal lengths. Canon cites their Extenders as usable with their 135mm and longer primes, and the 70-200mm and 100-400mm zooms. I also know that the Extenders can be used with the 90mm TS-E, but am not sure about the shorter TS-E lenses.

It is possible to use both... a 12mm extension tube and one of the Canon teleconverters together, to get around this physical limitation. Set up this way, the lens isn't going to be able to focus to infinity, but shootin' macro that really isn't a concern anyway.

You also can get third party teleconverters that do not have the protruding front element, so will be able to mount on more Canon or Canon-mount lenses. Some of them are quite good. Sigma makes both 1.4X and 2X in Canon mount and might work well with a Sigma lens (I haven't used them so can't say about IQ). The Kenko 1.4X also are considered quite good. Their latest 1.4X "MC-4" DGX - which is a less expensive model - is surprisingly good... Both their higher-end "Pro 300" DG and DGX 1.4X are considered very close to the quality of the Canon.

Due to lower light being transmitted and the extra electronic connections added by either extension tubes or teleconverters, expect AF to slow down and be more inclined to hunt in difficult lighting.

Yes, you can reverse-mount a lens to get higher magnification. Often a 50mm or short tele is best used for this. One drawback of doing this with modern Canon gear is loss of control over the lens' aperture. You can't stop it down via the controls on the camera (there is a way, but it involves un-reverse-mounting the lens, mounting it normally, dialing in the aperture you want, pressing and holding DOF preview while unmounting the lens, re-reverse-mounting it, then taking your shot... repeat any time you want to change the aperture... ugh!). An easier approach is to use a vintage lens with a manual aperture control ring, adapted for use on modern EOS.

Another trick is to reverse-stack two lenses. Here a shorter focal length is reversed, then attached to the front of a longer focal length. The reversed lens acts as sort of a macro diopter. For example, a 28, 35 or 50mm lens might be reverse mounted on the front of a 100 to 135mm lens. Doing this, the main lens still offers AF and aperture control, and there is no need to stop down the aperture of the reversed lens. The tricky part is matching up a short lens with similar diameter to the front of the main lens you'll be using for this purpose. The reversed lens needs to be close to the same or larger in diameter (making it difficult, for example, to do with the Canon 135/2 which has a 72mm filter thread... few 28 to 50mm lenses have that size filter thread or larger). There are reversing rings, male-threaded on both sides, sold for just this purpose.

You also can add a diopter to the front of a lens, just like a filter but to increase magnification. Canon offers the 250D and 500D in various diameters. (Note: the 250D is actually the stronger of the two and is designed for lenses 135mm and shorter. The 500D is designed for lenses 70mm and longer, if memory serves.) Nikon, Zeiss, B+W and others have offered high quality diopters in a variety of strengths. With all these, there's some loss of image quality due to adding optics.... often not multi-coated... to the front of the lens. They also are limited in use to lenses with the same filter thread size... and rather pricey. (Forget about the cheap "macro filter" sets you might find online and in camera stores... they are optically horrible and trach your image quality).

Or, pick up a Canon MP-E 65mm... It's an ultra high magnification macro lens. It can't shoot infinity at all. In fact it starts out at 1:1, where most macro lenses stop, and goes up to 5:1 magnification. This lens extends in length a great deal as it's focused to higher magnifications, resulting in light fall-off within the lens and effectively smaller apertures at higher magnificatioins. Plus it is manual focus only. But it's got high enough magnification to fill a FF camera's viewfinder with a grain of rice.

At higher magnifications, figure on using a tripod. First, even the slightest movement of camera or lens if greatly magnified. Plus it's hard to get enough depth of field, so smaller apertures may be necessary, which in turn means longer shutter speeds (and/or higher ISOs), making it even harder to steady a shot.

Alternatively, add light with a flash. It doesn't need to be a macro-specific flash. A single Speedlite... perhaps with a diffuser of some sort (I use a couple layers of white gauze bandage held on with a rubber band), connected with an off-camera shoe cord and handheld or on a special bracket... can work surprisingly well. Relative to a tiny subject, it's sort of like a giant softbox in the sky. You can use a reflector for fill, if necessary.

Or, there are macro flashes. I use the Canon MT 24EX Twinlite for up to 1:1 or maybe a little beyond. I use a special bracket for the Twinlite, that allows for more flexibility positioning the flash heads. At higher magnifications, I use the MR 14RX Ringlite (I just don't care for ring flashes at lower magnifications... it looks sort of flat and "clinical" to me).

Wow thank you! This is the best answer I've gotten. That pretty much explains everything. I just re-read your post again. It's almost like I've taken a Macro photography class

Thanks !