Teleconverter Stack Shots

[Bill Anderson]

I had a Canon 2x series II teleconverter which I never used because I thought the images were too soft. This summer Kenmore Camera had a used Canon 2x series III for sale, so I purchased it. I have been very happy with the images I have gotten using it with my 4.0/500L telephoto lens. It has become a regular part of my "super telephoto" package that gives me a 1,000mm focal length when used with my full frame 5DIII.

Due to their construction , my two Canon 1.4x teleconverters (a series II and a series III) cannot be stacked with the 2x TC. Some after market 1.4x TC's can be stacked due to a different construction. I had an old after markert 1.4x TC gathering dust in my pickup, so I tried coupling it to the 2x III TC. It fit, so I took some photos for the equipment geeks to look at for comparison.

These photos were taken from the #2 viewing platform at the marsh on 10-26 & 28-18. All are uncropped unless otherwise noted.

5DIII + 24-105L wide angle zoom @ 50mm. I have been told that 50mm is the normal (1x) view. Note the Pt. Edwards eagle perched on the tree above the new condos. I thought it looked larger to my naked eye, but it may have been the horizon effect.

5DIII + 500L telephoto + 2x II TC (1000mm focal length).

5DIII + 500L telephoto + 2x III TC + 1.4x TC (1400mm focal length).

 

[Bill Anderson]

Looking across the marsh at the contractor's building on the old Unocal site, which is not open to the public.

5DIII + 24-105L wide angle zoom @ 50mm.

5DIII + 500L telephoto + 2x III TC + 1.4x TC (1400mm focal length).

I cropped a photo of the doors to see if the image were clear enough to read the signs.

Railroad maintenance equipment parked on the siding west of the marsh.

5DIII + 24-105L wide angle zoom @ 50mm.

5DIII + 500L telephoto + 2x III TC + 1.4x TC (1400mm focal length).

 

[Bill Anderson]

The auto focus does not work with the stacked TC's, so I turned it off on the 500L telephoto lens. Knowing that the stacked TC's would decrease the available aperture opening, I shot in Tv mode with auto ISO and let the camera pick the optimal ISO and aperture settings. I also put my hand over the barrel of the lens to minimize camera shake, which is bound to show up at 1400mm or 28x.

 

[Terry O]

Interesting comparisons Bill. With a little sharpening (based in part on my playing with shots I took at the same time as you did) I think it will be hard to tell how much we were able to multiply the focal length by just looking at the results. It will be interesting to get a couple of shots printed in 11X14 format to see.

Terry

 

[Bill Anderson]

I want to try some stacked shots using the 7DII + 2x III TC + 1.4x TC. The 7D II has a crop frame sensor (1.6x crop factor) during our next sunny day, whenever that may be.

 

[Bill Anderson]

The aftermarket 1.4x teleconverter I used to couple with the Canon 2x III TC was a Kenko. Kenko also makes a 2x teleconverter.

https://kenmorecamera.com/product/8302/kenko-2x-pro-300-teleconverter-eos

 

[Bill Anderson]

One more experiment stacking the 2x and 1.4x teleconverters, this time using the 7DII, which has a crop frame sensor. This took place on a windy Monday afternoon (10-29-18) at the marsh with the eagle obligingly perching in the same tree atop Pt. Edwards.

7DII + 500L telephoto lens + 2x TC + 1.4x TC. Effective focal length = 2240mm.

7DII + 500L telephoto lens + 2x TC. Effective focal length = 1600mm.

The second image is much clearer. Stacking the 7DII + 2x TC + 1.4X TC gave me real problems with vibration whenever I squeezed the shutter. A strong wind did not help matters either.

Stacking the 2x TC and the 1.4 TC on the full frame sensor 5DIII gives me a 1400mm focal length. With its crop frame sensor, I can get an effective focal length of 1600mm with the 7DII + 2x TC without the use of a second teleconverter. It also gives me the advantage of being able to shoot at f/8 with a functioning autofocus.

Lessons learned: Experimenting was fun, but I'll stick to using just the 2x III TC with the 5DIII + 500L telephoto lens. This lets me shoot at f/8 with a functioning autofocus. If I really need the extra reach, I'll use the 7DII + 2x III TC rather than stack teleconverters on the 5DIII. I usually use the 7DII only if the light is good, as it does not handle high ISO settings as well as the 5DIII.

 

[Terry O]

I agree, Bill. I think the 1.4x stacked on the 2x really doesn't offer much, considering no auto focus and a noticeable degradation of sharpness.

Terry