Canon extender 2x mk ll on Canon 6D produces black images - SOLVED

[Starlight90]

Hello everyone,

I have a Canon 6D camera and 2 2x mk ll EF extenders (canon official), I have read that you can stack these extenders and get a bigger and better view of an object.

The Lens I'm working with is a  canon EF 100-400mm f/4.5-5.6 L IS USM Lens with the 2 extenders, however my live view doesn't with them both attached to my camera and lens, but I can see through the view finder, after I've taken some photos of the moon just to test and observe, I go back to check to see how they came out, it's all black, like nothing was taken, just a black void.

Can anyone advise?

Thanks 

[ebiggs1]

Outstanding and very clear. Hats off to you Trevor great analysis.

[Tronhard]

Thank you Ernie.
I am curious... Your new logo/avatar, what is that from - is it a college team mascot?

[Starlight90]

Ok and thank you for your replies. I think that you are too persistant and I have read all and responded to most people's replies. You've not really been helpful but instead, just critizing in something you obviously don't really know anything in. 

Again, thank you. 

[johnrmoyer]

I sometimes stack extenders, even though I am told that it cannot work. I wish you good luck. It is easier with a newer mirrorless camera, but I also did it with my EOS 80D. I sometimes had black images with my EOS 80D as you mention, but sometimes it worked. It worked better for me in live view than using the viewfinder. I know I have different cameras and different lenses than you, but I hope some of this might be helpful anyway.

With my EOS R5, each time I update the firmware I have to experiment to learn which combination works. It costs less than a high quality long lens.

EF100-400mm f/4.5-5.6L IS II USM +1.4x III + Kenko TELEPLUS HD C-AF 2X DGX , 1120mm

EF100-400mm f/4.5-5.6L IS II USM +1.4x III + Kenko TELEPLUS HD C-AF 2X DGX , 1120mm

I could not identify the smaller birds until I stacked the extenders to get 1120mm. I guess the distance to be about 300 meters. I was not permitted to get closer.

[Tronhard]

It would be interesting to know what extenders you stack - specifically are the BOTH 2x, MkII extenders?
I would observe that the images you show are of brightly lit subjects. I am honestly not responding to a general discussion of using stacked extenders, I am looking at the specifics of what the OP wants to photograph, and in that context I wonder how relevant your images are?

Since the OP has said they want this setup for, and I quote: "Mostly for planetary photography and moon photography", by far the best light scenario is shooting the moon, which is a very, very bright object - a planet is incredibly small and dim in comparison and bears no resemblance to shots take in daylight on earth, or even of the moon.
Given that the extenders the OP wishes to use are not the latest, so have limitations in exposure and focus, and compatibility with a lot of cameras; and stacking 2, 2x extenders will reduce their light by 4 stops, i.e. 1/16 of the light from a lens alone, my point is that the camera is not able to show an image in live view because the shutter speed would be too slow, and if it did capture an image, I would expect that the earth's rotation would cause a star trail.  If that is a risk for the moon, what is it likely to be for a planet?

[johnrmoyer]

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@Tronhard wrote:

It would be interesting to know what extenders you stack - specifically are the BOTH 2x, MkII extenders?
I would observe that the images you show are of brightly lit subjects. I am honestly not responding to a general discussion of using stacked extenders, I am looking at the specifics of what the OP wants to photograph, and in that context I wonder how relevant your images are?

Since the OP has said they want this setup for, and I quote: "Mostly for planetary photography and moon photography", by far the best light scenario is shooting the moon, which is a very, very bright object - a planet is incredibly small and dim in comparison and bears no resemblance to shots take in daylight on earth, or even of the moon.
Given that the extenders the OP wishes to use are not the latest, so have limitations in exposure and focus, and compatibility with a lot of cameras; and stacking 2, 2x extenders will reduce their light by 4 stops, i.e. 1/16 of the light from a lens alone, my point is that the camera is not able to show an image in live view because the shutter speed would be too slow, and if it did capture an image, I would expect that the earth's rotation would cause a star trail.  If that is a risk for the moon, what is it likely to be for a planet?

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You are correct as usual. But, with limited budget, extenders are an option. It requires more work, maybe even aligning and stacking multiple images. The older and third party extenders require even more work because there is less contrast and more blur. I gave three brightly lit examples at three distances. The shutter speed must be lower than one would wish and the ISO must be higher than one would wish. If the primary constraint is budget, then it might be the only available option. I used a deconvolution to reduce small aperture diffraction blur and increase contrast of edges.

I use a Canon mk III with a Kenko which like gives better image quality than two Canon mk II extenders. By better quality, I mean greater contrast for small features in the image. The Monarch butterfly was hand held and the birds were hand held but braced against a blind.

[Starlight90]

Thank you for your advice and photos, this has helped me understand a bit better with the extra equiptment I have.

[ebiggs1]

Your butterfly is amazing. Your Moon and small birds not so much. I would not keep either of those as good pictures.

Sorry, just MHO.

[johnrmoyer]

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@ebiggs1 wrote:

Your butterfly is amazing. Your Moon and small birds not so much. I would not keep either of those as good pictures.

Sorry, just MHO.

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Thanks. The butterfly moved and there is motion blur (shutter speed limit I mentioned). The birds were very far away over water with varying air densities diffracting the light, but the photo documented their identification and was uploaded to ebird. The moon photo was made when I was experimenting with extenders and not on a night when the air was clear and motionless (also too much noise to correct small aperture diffraction blur).

I expect that I sometimes keep photos for different reasons than you do. I have much better photos of butterflies, birds, and the moon, but the circumstances of how, when, and where these photos were made makes them interesting to me.

[Waddizzle]

SOLVED!

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