Stacked TCs - 1.4x III + 12mm Extension Tube + 2x III

[scyrene]

Oops, sorry, I misread. I think you'd need to stop down a lot, as the 2x extender will exaggerate the lens's flaws, and ultrawide aperture lenses (even this one) have a lot of optical problems wide open. I've combined the extender with extension tubes and the 24-105mm f/4L IS lens and it worked a bit like I'd imagine the 180L does - near-macro to true macro magnification at some distance, but it wasn't the best quality and autofocus speed is abysmal.

 

[arbitrage]

According to this article by Arthur Morris (http://www.birdsasart-blog.com/2013/10/19/suns-of-a-gunstacking-teleconverters-extenders-with-series-ii-super-telephoto-lenses-and-more/) if you stack with the 2xIII against the lens then you maintain AF at infinity but with the 1.4xIII against the lens you lose infinity focus. So camera+1.4xIII+12mm+2.0xIII+lens may give you infinity focus. I have tried this and AF is horrible but you can MF and get it to work. I tried with the 300II which should be the ideal lens to try such a combo with.

 

[mackguyver]

According to this article by Arthur Morris (http://www.birdsasart-blog.com/2013/10/19/suns-of-a-gunstacking-teleconverters-extenders-with-series-ii-super-telephoto-lenses-and-more/) if you stack with the 2xIII against the lens then you maintain AF at infinity but with the 1.4xIII against the lens you lose infinity focus. So camera+1.4xIII+12mm+2.0xIII+lens may give you infinity focus. I have tried this and AF is horrible but you can MF and get it to work. I tried with the 300II which should be the ideal lens to try such a combo with.

I'm not at my house right now, but I remember that the order mattered as you say and yes, AF sucks, but the idea is to use this for rare situations where the extra distance is needed and IQ isn't the most important factor.

 

[hendrik-sg]

The best extender is a crop camera. It gives y deeper FOV (if y want), and by more pixel desity y get more magnification, without accepting IQ reduction by additional glass.

I have expierience with the old 300 2.8 IS, a 2xiii and a 50d. With this combination already its really difficult to overcome camera (and tripod and lens foot) shake, means its better than cropping only under ideal conditions.

Other than from a technical point of view, i dont see much use for a manual Focus, 840mmm f8.0 combination on a crop camera, maybe exept under very bright lighting conditions. Normally, cropping will give better Image quality.

For the frequently seen moon shots, with normal techique athmospheric limitations may be more relevant than all other sources of IQ reduction.

 

[scyrene]

The best extender is a crop camera. It gives y deeper FOV (if y want), and by more pixel desity y get more magnification, without accepting IQ reduction by additional glass.

I have expierience with the old 300 2.8 IS, a 2xiii and a 50d. With this combination already its really difficult to overcome camera (and tripod and lens foot) shake, means its better than cropping only under ideal conditions.

Other than from a technical point of view, i dont see much use for a manual Focus, 840mmm f8.0 combination on a crop camera, maybe exept under very bright lighting conditions. Normally, cropping will give better Image quality.

For the frequently seen moon shots, with normal techique athmospheric limitations may be more relevant than all other sources of IQ reduction.

Well I for one don't carry a crop body and a full frame body on most of my hikes (except sometimes the EOS-M, which is hardly ergonomic with a super telephoto lens attached). I would double up (or more) the converters *only* if the target (invariably a bird) was very notable and very inaccessible (like certain sea ducks we get here, that stay hundreds of metres or more offshore). These shots will never match up in image quality to ones taken with just one extender attached (still less a bare lens) but they can be of use for recording species.

As for atmospheric conditions, once you get to those focal lengths they do make a huge difference - which is why I would recommend image stacking for static subjects. If you do that, you can indeed extract more detail the more focal length you have (with diminishing returns). My last moon shots were taken at 5600mm, and stacking revealed greater detail than 4000mm, 2800mm, etc.

One last thought - even if image quality is no better than cropping, with small/distant subjects, having them bigger in the viewfinder can help with manual focus (as autofocus is too unreliable/will not work with these setups). Also if the final images are resized to the same scale, noise will be less visible (with equal settings) in the image that was cropped less/shrunk more (although adding more extenders requires higher ISO which can introduce more noise, so they often even out). Edit: image stacking will also drastically reduce noise.

 

[TexPhoto]

My cheap ebay 13mm extension tube, (no idea why they went with 13) is all metal, at least in the mount and body.

 

[hovland]

According to this article by Arthur Morris (http://www.birdsasart-blog.com/2013/10/19/suns-of-a-gunstacking-teleconverters-extenders-with-series-ii-super-telephoto-lenses-and-more/) if you stack with the 2xIII against the lens then you maintain AF at infinity but with the 1.4xIII against the lens you lose infinity focus. So camera+1.4xIII+12mm+2.0xIII+lens may give you infinity focus. I have tried this and AF is horrible but you can MF and get it to work. I tried with the 300II which should be the ideal lens to try such a combo with.

I'm not at my house right now, but I remember that the order mattered as you say and yes, AF sucks, but the idea is to use this for rare situations where the extra distance is needed and IQ isn't the most important factor.

If needed you also have the option of stacking a 2.0xIII with a 1,4 sigma. Af works on my 70-200, but sucks. But it will probably be better to only use the 2.0xIII and just crop. Physically it also works to stack a 2.0xIII and a 2,0 sigma and even add the sigma 1,4, without using any extension tubes.

 

[R1-7D]

Sorry if this is a bit off topic, but since we're talking about extenders and extension tubes already I don't see the need to start another thread.


If I use a 2x extender and then a 12mm extension tube...is it possible to use the 100 f/2.8L with this combination?

 

[scyrene]

Sorry if this is a bit off topic, but since we're talking about extenders and extension tubes already I don't see the need to start another thread.


If I use a 2x extender and then a 12mm extension tube...is it possible to use the 100 f/2.8L with this combination?

Yeah, I think I've done that. The 12mm extension tube should make the 2x extender fit any lens (although I'd be careful with ones like the 85L which has a very exposed rear element). With a macro lens like the 100L you'll get a pretty good setup for smaller insect subjects, although I'd stop down and you'll lose infinity focus as always with the extension tubes.

 

[R1-7D]

Sorry if this is a bit off topic, but since we're talking about extenders and extension tubes already I don't see the need to start another thread.


If I use a 2x extender and then a 12mm extension tube...is it possible to use the 100 f/2.8L with this combination?

Yeah, I think I've done that. The 12mm extension tube should make the 2x extender fit any lens (although I'd be careful with ones like the 85L which has a very exposed rear element). With a macro lens like the 100L you'll get a pretty good setup for smaller insect subjects, although I'd stop down and you'll lose infinity focus as always with the extension tubes.

Thanks! I just tried it... Man, unless the camera is on a tripod it's next to impossible to hold it steady. Sharpness really suffers, even when stopped down to f/8.

The lens retained it's f/2.8 aperture, however, which was cool!


Thanks again for the information.

 

[mackguyver]

R1-7D, now you know how I feel when I put the 2x on my 180mm macro, which makes it a 360mm (non-IS) lens! I might have to give the double-extender a shot on it as it's also a crazy sharp lens and getting a 504mm 2.8x macro lens sounds pretty cool, other than the DOF and light requirements...

 

[scyrene]

Sorry if this is a bit off topic, but since we're talking about extenders and extension tubes already I don't see the need to start another thread.


If I use a 2x extender and then a 12mm extension tube...is it possible to use the 100 f/2.8L with this combination?

Yeah, I think I've done that. The 12mm extension tube should make the 2x extender fit any lens (although I'd be careful with ones like the 85L which has a very exposed rear element). With a macro lens like the 100L you'll get a pretty good setup for smaller insect subjects, although I'd stop down and you'll lose infinity focus as always with the extension tubes.

Thanks! I just tried it... Man, unless the camera is on a tripod it's next to impossible to hold it steady. Sharpness really suffers, even when stopped down to f/8.

The lens retained it's f/2.8 aperture, however, which was cool!


Thanks again for the information.

Well remember, the reported aperture won't take account of the extender, since the camera body won't know it's there. So "f/2.8" is actually f/5.6. Also, at that magnification (up to 2x), use of a flash is almost essential. Add a flash, set it to the sync speed (e.g. 1/200), and you can hand hold easily. I was hand holding to 10x magnification today, albeit half resting on a surface (MP-E at max + 2x).

 

[R1-7D]

Sorry if this is a bit off topic, but since we're talking about extenders and extension tubes already I don't see the need to start another thread.


If I use a 2x extender and then a 12mm extension tube...is it possible to use the 100 f/2.8L with this combination?

Yeah, I think I've done that. The 12mm extension tube should make the 2x extender fit any lens (although I'd be careful with ones like the 85L which has a very exposed rear element). With a macro lens like the 100L you'll get a pretty good setup for smaller insect subjects, although I'd stop down and you'll lose infinity focus as always with the extension tubes.

Thanks! I just tried it... Man, unless the camera is on a tripod it's next to impossible to hold it steady. Sharpness really suffers, even when stopped down to f/8.

The lens retained it's f/2.8 aperture, however, which was cool!


Thanks again for the information.

Well remember, the reported aperture won't take account of the extender, since the camera body won't know it's there. So "f/2.8" is actually f/5.6. Also, at that magnification (up to 2x), use of a flash is almost essential. Add a flash, set it to the sync speed (e.g. 1/200), and you can hand hold easily. I was hand holding to 10x magnification today, albeit half resting on a surface (MP-E at max + 2x).

Interesting about the aperture. I was using a flash -- 580 EX II -- at exactly 1/200. Still, at extreme close-ups of subjects...I did not have much luck keeping it steady.

I also found manual focusing was an absolute must. Normally with Macro I like to manual focus anyways, but I sometimes use autofocus to get an approximate...but this lens combo did not want to focus at all. It just kept hunting and hunting.

Anyways, it's cool that this can be done. Gotta love tinkering with all the equipment. Thanks for the help.

 

[scyrene]

Sorry if this is a bit off topic, but since we're talking about extenders and extension tubes already I don't see the need to start another thread.


If I use a 2x extender and then a 12mm extension tube...is it possible to use the 100 f/2.8L with this combination?

Yeah, I think I've done that. The 12mm extension tube should make the 2x extender fit any lens (although I'd be careful with ones like the 85L which has a very exposed rear element). With a macro lens like the 100L you'll get a pretty good setup for smaller insect subjects, although I'd stop down and you'll lose infinity focus as always with the extension tubes.

Thanks! I just tried it... Man, unless the camera is on a tripod it's next to impossible to hold it steady. Sharpness really suffers, even when stopped down to f/8.

The lens retained it's f/2.8 aperture, however, which was cool!


Thanks again for the information.

Well remember, the reported aperture won't take account of the extender, since the camera body won't know it's there. So "f/2.8" is actually f/5.6. Also, at that magnification (up to 2x), use of a flash is almost essential. Add a flash, set it to the sync speed (e.g. 1/200), and you can hand hold easily. I was hand holding to 10x magnification today, albeit half resting on a surface (MP-E at max + 2x).

Interesting about the aperture. I was using a flash -- 580 EX II -- at exactly 1/200. Still, at extreme close-ups of subjects...I did not have much luck keeping it steady.

I also found manual focusing was an absolute must. Normally with Macro I like to manual focus anyways, but I sometimes use autofocus to get an approximate...but this lens combo did not want to focus at all. It just kept hunting and hunting.

Anyways, it's cool that this can be done. Gotta love tinkering with all the equipment. Thanks for the help.

I'm glad you're having fun! Macro is one of the most fun areas of photography I reckon. As for steadiness, you'll get better - it takes practice.

I don't even bother with AF on that lens bare if I'm going to 1x magnification, let alone 2x - it just can't keep up with tiny movements of you or the subject, even with its IS function. With the flash, you might want to boost the power (manually dialling it a stop or two higher) as you lose a lot of light getting very close to subjects. Or use the flash off-camera if you can. If it has high-speed sync (I've only used the 600EX-RT which does), you could try going to a faster shutter speed. Lots of variables to play around with, I'm sure you'll find something that works

 

[weilin]

Since we're messing around with stacking teleconverters... why limit it to EF lenses, what about... a telescope...

The images attached are shot with a sky-watcher ProED 120mm Doublet APO Refractor + 0.85x reducer/field flattener. It's natively 900mm but with the reducer it's 765mm. The Camera is EOS 5D3 at ISO 800.

Image 1: ProED + reducer (765mm)
Image 2: ProED + reducer + 1.4x tele (1071mm)
Image 3: ProED + reducer + 2.0x tele (1530mm)
Image 4: ProED + reducer + 1.4x tele + 12mm extension + 2.0x tele (2142mm)

Any thoughts on which is the sharpest?

 

[mackguyver]

I finally had a suitable subject to try the stacked extenders - in this order (1.4x III + 12mm Extension Tube + 2x III, then 300 f/2.8 IS II) and I had some trouble with focus because the tree the owl was on was moving, but I found with IS on, I was able to do a good job using the viewfinder. It was too dark in the shade to use LiveView unfortunately, but I did use a cable release & tripod. CA was minimal, but contrast was reduced around 25% and sharpness probably around 50%. It's still a very usable image for anything 8x10 and smaller - here's the full photo, uncropped:

 

[AlanF]

Was the order camera 1.4x III + 12mm Extension Tube + 2x III lens or lens 1.4x III + 12mm Extension Tube + 2x III camera?

 

[scyrene]

I finally had a suitable subject to try the stacked extenders - in this order (1.4x III + 12mm Extension Tube + 2x III) and I had some trouble with focus because the tree the owl was on was moving, but I found with IS on, I was able to do a good job using the viewfinder. It was too dark in the shade to use LiveView unfortunately, but I did use a cable release & tripod. CA was minimal, but contrast was reduced around 25% and sharpness probably around 50%. It's still a very usable image for anything 8x10 and smaller - here's the full photo, uncropped:

Looks good to me! Which lens was that? I find CA noticeable with the 2x extenders, and adding a second one will only exaggerate that, but maybe I have a very low tolerance for it (not that I can see any in that photo, especially good given the white background).

Ps did you stop down? I find it helps a lot with sharpness in this situation.

 

[AlanF]

I finally had a suitable subject to try the stacked extenders - in this order (1.4x III + 12mm Extension Tube + 2x III) and I had some trouble with focus because the tree the owl was on was moving, but I found with IS on, I was able to do a good job using the viewfinder. It was too dark in the shade to use LiveView unfortunately, but I did use a cable release & tripod. CA was minimal, but contrast was reduced around 25% and sharpness probably around 50%. It's still a very usable image for anything 8x10 and smaller - here's the full photo, uncropped:

What does sharpness being reduced 50% mean? Does that mean with 2x+1.4x relative to bare lens? Since adding a 2xTC can increase resolution by a maximum of x2 and a 1.4xTC by a maximum of x1.4, it doesn't look as if you are gaining anything by stacking them.

 

[scyrene]

What does sharpness being reduced 50% mean? Does that mean with 2x+1.4x relative to bare lens? Since adding a 2xTC can increase resolution by a maximum of x2 and a 1.4xTC by a maximum of x1.4, it doesn't look as if you are gaining anything by stacking them.

You've got a point. But remember the 2x extender increases the pixels on target by 4x. 2x in two dimensions, if that makes sense (so, say the bare lens gave you a subject 1000x1000 pixels, that would be 1MP; doubling the focal length gives you 2000x2000, which is 4MP).

It has a couple of advantages I would say. First, it makes the subject bigger in the viewfinder, which can help if you're focusing manually. Second, if you were to crop to the same size the noise patterns would be different. again it's hard to put into words. But shrinking down an image taken with a longer focal length would reduce the appearance of noise, whereas simply cropping to give the same field of view at a shorter focal length makes the noise more apparent.

In my subjective view, 2x + 1.4x does give extra resolution. Beyond that, you're not gaining any extra details, but the above points hold (the big exception being stacked astrophotography, where you regain all that resolution by combining multiple images, so any extra focal length is good).