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 

[normadel]

I see no mention of anyone actually checking the manual for the LENS.

It clearly says extenders CANNOT be used more than one at a time. Also other information regarding extender use.

https://www.canon-europe.com/support/consumer/products/lenses/ef/ef-100-400mm-f45-56l-is-usm.html?ty...

Oddly enough, Canon USA  does not show the manual, while Canon Europe does.

[Waddizzle]

You might not see it at Canon USA because it is probably no longer serviced.  But they should still have it available, IMHO.

I think he might need to adjust his exposure.  But then again, maybe not.  Live View cannot show you what a really long exposure, greater than 30 seconds, wouldl actually look like. It might with ExpSIM.  But I suspect ExpSIM runs out of gas beyond 30 seconds.

[Waddizzle]

“ Live view reads the image off the sensor with the aperture closed down. “

Maybe.  If the exposure is set with the Aperture wide open, then Live View with ExpSIM enabled should see the same exposure as the OVF.

The problem could be that ExpSIM is running out of gas beyond a 30 second exposure.  I noticed that he mentioned a tracking mount.  The issue could be as simple as the exposure times are too long for Live View in Bulb Mode.

[Waddizzle]

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@Waddizzle wrote:

“ Live view reads the image off the sensor with the aperture closed down. “

Maybe.  If the exposure is set with the Aperture wide open, then Live View with ExpSIM enabled should see the same exposure as the OVF.

The problem could be that ExpSIM is running out of gas beyond a 30 second exposure.  I noticed that he mentioned a tracking mount.  The issue could be as simple as the exposure times are too long for Live View in Bulb Mode.

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Negative on that theory.  My 6D displays an image Live View wtih or without ExpSIM enabled.  Except I am not using stacked teleconverters, and I am using the Mark II version of the lens.

No idea what version teleconverters the OP is using, though.  No idea what Live View is using for Tv in Bulb Mode.  It does not display a shutter speed.

[ebiggs1]

A tel-con and an extender is the same animal, my friend. Just different nomenclature and still a very bad idea.

[normadel]

The original post tells what extender version he is using.

[FloridaDrafter]

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@Starlight90 wrote:

However, the equipment I currently own, none of it is cheap. But if I need to sell it all off to afford the better equipment. Then so be it. 

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This is probably the best video I've come across about shooting astrophotography with just a camera. The guy is using an EOS RA camera, RF 85mm f/1.2, and stacking in PhotoShop. It is a very detailed tutorial and may be a bit dry at times because he goes into a lot of theory on light and what causes noise, etc. But IMO, a worthy watch even if you aren't into astrophotography. It is amazing how much detail he gets.

Here is the link.

Newton

[Starlight90]

Being in the UK, we do have some amazing sites and camera shops that the USA probably doesn't. The camera shop I spoke to who deal with canon equiptment did say the MK ll extenders can be stacked with that paticular lens. So I don't to be honest.

But can any of us really afford a £13k lens that will do the job we need it to do? 

[Tronhard]

There is an analogy about dentistry here.  A man has an aching tooth, and going to dentist after dentist they consistently tell him that he needs to have that tooth removed.  However, he continues until he finds one that says, it's ok to just leave it there.

You have asked us for advice on this issue. You have received consistent feedback, and in some cases with references to documentation from Canon, that stacking 2x extenders on your camera to get a decent image of the very dim subjects of the night sky is not a practical solution. Yet, you persevere until you find someone who claims to know, that is prepared to tell you it's OK.  Telling the forum - which has world-wide contributors, that somehow an English source is more authoritative, is dubious and irrelevant.  The physics speak for themselves.

You do this on the basis of economics but you fail to bring into the equation that you get what you pay for.  If you are as serious about astro as you suggest then you sell surplus gear (as you have suggested) save up and get the right gear.

I don't know how much it will cost you to get an adapter for the  solar scope you have but I honestly think you are persuading yourself into an inferior optical solution to get a quick result.

I honestly wish you well, but I'm pessimistic as to the results you will get.

[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.