Canon 2x and 1.4x mk3 extenders

[Dylan777]

Thanks Alex for sharing, great info

Is that 300 or 400mm you shooting with?

 

[gbchriste]

Very cool, but let me ask this: Is this combo getting you better results than just cropping? I'm not saying it is not, but that is the thing about a teleconverter, or combination of converters is it has to outperform just cropping the image.

If you shoot the moon with just the 2.0X and then crop, is there less less detail?

After reading the original post I gave it a try just for fun. And yes the results were really quite good and better than cropping.

When you think about it, it seems almost self-evident that shooting at the higher magnification would provide better results than cropping in to an image taken at smaller magnification - ignoring for the moment any IQ issues induced soley by higher magnification such as camera shake or shallow DOF. With those other variables under control, the higher magnification has to produce an image of more exquisite detail.

For any given detail in the image - a crater for example - doubling the magnification will increase the number of pixels used to image that detail by a factor of 4.

Let's take a hypothetical. Assume I shoot an image of the moon with a 400mm lens and one of the craters in that image takes up a matrix of pixels on the sensor measuring 50X50 pixels, for a total of 2500 pixels. Now I want to increase the apparent size of that crater by cropping in to the image to give an angle of view equal to what I would have had if I'd shot with an 800mm lens. Even though I have doubled size of that portion of the image in each dimension, I still haven't increased the number of sensor pixels contributing to that part of the image so there is no additional detail to be garnered.

However, if I had taken the image with an 800mm lens to begin with, that portion of the image would be twice as large on the sensor than the previous shot, measuring 100X100 pixels. Because of the squaring effect, there are now 100X100, or 10000 pixels contributing detail for that same portion of the image. The uncropped image will be similar in angle of view to the previous cropped image, but will have a much higher pixel density and thus much higher resolving power vis-a-vis the image details.

 

[neuroanatomist]

When you think about it, it seems almost self-evident that shooting at the higher magnification would provide better results than cropping in to an image taken at smaller magnification - ignoring for the moment any IQ issues induced soley by higher magnification such as camera shake or shallow DOF. With those other variables under control, the higher magnification has to produce an image of more exquisite detail.

What about any IQ issues introduced by the process of magnification, itself? Specifically, I would bet that cropping an image would yield results superior to increasing magnification with a crappy TC.

 

[gbchriste]

When you think about it, it seems almost self-evident that shooting at the higher magnification would provide better results than cropping in to an image taken at smaller magnification - ignoring for the moment any IQ issues induced soley by higher magnification such as camera shake or shallow DOF. With those other variables under control, the higher magnification has to produce an image of more exquisite detail.

What about any IQ issues introduced by the process of magnification, itself? Specifically, I would bet that cropping an image would yield results superior to increasing magnification with a crappy TC.

I believe I mentioned IQ issues related to magnification itself..."ignoring for the moment any IQ issues induced soley by higher magnification such as camera shake or shallow DOF. With those other variables under control, the higher magnification has to produce an image of more exquisite detail."

With that caveat, I didn't think it necessary to go through every single magnification-related variable that might affect IQ, with a crappy TC being one of the possibilities. Looks the OP is invested in top of line L-series lenses and TCs, so I'm commenting on the assumption that crappy gear isn't a factor.

Therefore my analysis was limited strictly to the difference in detail resolution based on pixel density in the image, when comparing an image that is cropped to yield the same image that shooting at a natively higher magnification would yield.

 

[AlanF]

You are, of course, correct that a quality longer lens gives better resolution than a quality shorter one, all things being equal. What we want to know is whether stacking TCs on to a particular lens does lower its IQ to such an extent that it negates the gain in focal length. The series II telephotos and series III TCs are beautifully designed to work well together. In my experience that is so but adding a 1.4 to a 100-400 is no better than using PS to increase size by 1.4x. What I particularly want to know is the IQ effect on stacking two series III together. Why did Canon stop us doing that? Was it intentional or what? My 5D III froze when I stacked a Kenko 1.4 TC onto a 2xTC III and a 300mm f/2.8 II.

 

[ForumMuppet]

Here is a shot I captured last night with my 7D + 1.4x TC III + 2x TC III + 300 f/2.8 IS II with a Kenko 12mm extension tube between the two TCs. The rig is a little too heavy for my tripod head, which started to drift, so this shot was hand held.

1/800 sec, f/5.6, ISO 400

 

[AlanF]

Thanks for the moon shot, the combination of lenses is just what I am interested in. Did you manually focus? It would be interesting to see 100% crops with and without the 1.4xTC.

 

[ForumMuppet]

Being that the framing was difficult to hold on the incline of my back yard, I was trying not to fall in a hole, I first used autofocus to find the ballpark. Then I switched the lens to manual focus and adjusted the focus ring to dial it in while resting my hands on top of the fence. Here is a 100% crop of the lower portion of the moon where the best detail resides. I will have to get back to you on the 'without' image.

I'm also going to be getting a new tripod rig so hopefully I can do some better focussed images once that arrives. I will also do some cropped tests with my 5DIII, too.

Higher resolution images can be seen on my website here

 

[AlanF]

Impressive, I'll buy a 12mm ring. Here is a photo I took last April using the 5DIII + 2xTC. I've increased the pixwl dimension by 1.4x1.6 to allow for the crop factor and the TC used by you. I haven't sharpened or noise reduced the image.

 

[ForumMuppet]

Very nice. What lens were you using? The Kenko extension tubes allow autofocus, so I would get them over the cheaper ones. Also note they are only in a kit for $199 with a 12mm, a 20mm and a 36mm tube. The Canon 12mm is sold alone for $84. The product description does not state it, but I am sure theirs is compatible with the AF as well.

 

[AlanF]

Very nice. What lens were you using? The Kenko extension tubes allow autofocus, so I would get them over the cheaper ones. Also note they are only in a kit for $199 with a 12mm, a 20mm and a 36mm tube. The Canon 12mm is sold alone for $84. The product description does not state it, but I am sure theirs is compatible with the AF as well.

f/2.8 300mm II + 2xTC III. I will go for the Canon because I presume it is strong enough to marry a monster lens to a heavy body without snapping in two.

 

[TexPhoto]

OK, Sorry. I think I wrote out all my text and copied the photo over the top.

I tried the 2XIII and 1.4XIII with a 13mm extender a friend of mine has. My 1D IV said Error!
My 5D III said, OK, but I can't focus. And My friend's 7D said...Error.

The Photo is actually just the 2X on my 400mm with my Mark IV


REX40053 by RexPhoto91, on Flickr

 

[Caps18]

Have you tried shooting the planets (Mars, Jupiter, Saturn)? I've used a 300 f/4 + 1.4x+2x and you could barely make out Jupiter and 4 moons if you digitally zoomed in quite a bit. I figure you need a 4000mm lens equivalent before it would be like a telescope.

If I had more free time and a few thousand dollars to play with, I would buy a GPS tracking telescope and mount my camera on to it. Then learn how to stack images in post processing.

 

[AlanF]

The moon shots were posted just as universal images for comparisons. I am interested in extra range for nature shots.

 

[AlanF]

I tried the 2XIII and 1.4XIII with a 13mm extender a friend of mine has. My 1D IV said Error!
My 5D III said, OK, but I can't focus. And My friend's 7D said...Error.

The Photo is actually just the 2X on my 400mm with my Mark IV

The Canon 12mm II just arrived. My 5DIII won't focus either manually or AF with the 1.4x III -12mm - 2x (or vice versa). What am I doing wrong? Does anyone want to buy a 12 mm Canon II extension ring, 1 day old, used twice?

 

[rpt]

I tried the 2XIII and 1.4XIII with a 13mm extender a friend of mine has. My 1D IV said Error!
My 5D III said, OK, but I can't focus. And My friend's 7D said...Error.

The Photo is actually just the 2X on my 400mm with my Mark IV

The Canon 12mm II just arrived. My 5DIII won't focus either manually or AF with the 1.4x III -12mm - 2x (or vice versa). What am I doing wrong? Does anyone want to buy a 12 mm Canon II extension ring, 1 day old, used twice?

He seems to have a 1DX. And the 1.4x is the first one mounted. Not sure if that matters. I tried my 5D3+1.4x+12mm+100-400L @400mm and it did not AF. Even manual focus was not possible. My 12mm macro extension tube is Kenko but I don't think that is the problem.

I guess this is one for Alex to field...

 

[tpatana]

Why no manual focus? The focus ring is stuck?

 

[rpt]

Why no manual focus? The focus ring is stuck?

Nope. Even going beyond infinity, objects at infinity do not come into focus.

 

[TexPhoto]

I tried the 2XIII and 1.4XIII with a 13mm extender a friend of mine has. My 1D IV said Error!
My 5D III said, OK, but I can't focus. And My friend's 7D said...Error.

The Photo is actually just the 2X on my 400mm with my Mark IV

The Canon 12mm II just arrived. My 5DIII won't focus either manually or AF with the 1.4x III -12mm - 2x (or vice versa). What am I doing wrong? Does anyone want to buy a 12 mm Canon II extension ring, 1 day old, used twice?

If the extension tubed has other uses of course. Marco for one. Also, it makes a good way to keep the 2 extenders in your camera bag.

 

[dgatwood]

Just for fun: Kenko 3x TC (live view focusing only) on a 70-300L f/4 (900mm equiv.) on a 6D