topic Re: Canon extender 2x mk ll on Canon 6D produces black images in Camera Accessories

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

Starlight90 — Tue, 13 Feb 2024 21:37:50 GMT

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

Re: Problems with extenders on canon 6D

Waddizzle — Wed, 31 Jan 2024 05:42:17 GMT

@Starlight90 wrote:
Hello everyone,

I have a Canon 6D camera and 2 2x mk ll EF extenders, 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

Where have you read this? Please post a link so we can review it. THX!

If you have not already downloaded a copy of the User Manual, then I suggest that you use this link. Download the PDF and search for phrase “lens groups”.

https://www.usa.canon.com/support/p/eos-6d

Re: Problems with extenders on canon 6D

Starlight90 — Wed, 31 Jan 2024 05:49:03 GMT

Hi and thanks for your reply. I own a physical manual.

I was also told by my local camera shop in Chester, Wilkinson camera here in England as well.

These are the sites:

https://www.quora.com/Can-I-attach-more-than-one-teleconverters-to-achieve-4x-or-8x-or-more-magnification#:~:text=You%20can%20stack%20multiple%20teleconverters,of%20a%20400%20mm%20lens.

https://www.dpreview.com/forums/thread/3710997

Re: Problems with extenders on canon 6D

Tronhard — Wed, 31 Jan 2024 06:05:55 GMT

Hi and welcome to the forum:
I'm not sure where you go this information from but the suggestion that one can get ' bigger and better' images does not fit conventional wisdom or experience, especially for any extender before the MkIII models.

There are serious issues with extenders working with the focus and apertures of different models of cameras - only certain bodies will support autofocus and autoexposure - in fact most extenders require a f/stop of f/8 and single point focus (if at all) and that is for most bodies with the MkIII (much improved extenders).

However leaving that aside, there is always a cost to adding an extender to any lens. Any 1.4x will cost at least one f/stop of light, while a 2.0x extender will cost two stops, and inevitably adding more lenses into the focal path will downgrade the image. Adding two extenders would result in a serious degradation of image, and cost at least 3 stops, but likely 4 stops - which translates 1/16 (2 to the power of 4) of the light transmission almost certainly resulting in diffraction issues. Furthermore, adding a lot of mechanical joints will degrade any weather sealing integrity of the camera and lens and likely slow down lens response even more than one.

I have shot with the MkIII versions of both 1.4x and 2.0 extenders, and would definitely recommend getting a lens that is built for the job. Adding two 2x extenders would provide a focal length of equivalent of 800-1600mm, and with that magnification and low light transmission, one would have to have the camera on a tripod.

Re: Problems with extenders on canon 6D

Starlight90 — Wed, 31 Jan 2024 06:06:39 GMT

Thanks for your reply, I don't use the auto focus on my lens, I always use manual focus, as I find it easier to control.

I know that with each extender, you do loose light, obviously depending on which extender that is use, as you have said.

As far as I am aware, you cannot stack mk lll extenders without an extension tube. Unfortunately I cannot afford the mk lll and the mk ll were both in my price range £140 each, where as the mk lll is £220 each as the lowest price.

Re: Problems with extenders on canon 6D

Tronhard — Wed, 31 Jan 2024 06:08:10 GMT

I am curious why you need the focal lengths you are seeking - up to 1600mm FL. It would be a false saving to get gear that will seriously degrade your images just to get extra FL.

Re: Problems with extenders on canon 6D

Starlight90 — Wed, 31 Jan 2024 06:18:13 GMT

Mostly for planetary photography and moon photography. At 800mm it's just not big enough, the bigger lenses are at least £5k plus and are way out of my range, and at the moment I'm unable to get the correct equipment for my skywatcher telescope, again, out of my price range.

So this is my best option at the moment.

Re: Problems with extenders on canon 6D

Tronhard — Wed, 31 Jan 2024 07:13:35 GMT

I would strongly suggest trying before you commit yourself. Astro will require relatively fast lenses to avoid tracking marks.

Have you considered shooting in APS-C mode to give you a 1.6 boost in Field of View.

Can you not get some kind of astro telescope to which you can fit an adapter?

Re: Problems with extenders on canon 6D

Starlight90 — Wed, 31 Jan 2024 07:42:31 GMT

My sky watcher is an astro telescope, I just can't afford the adaptors and due to muscle damage I can't lift it.

I used to do astro photography at high school with their dslr 20 years ago.

Re: Problems with extenders on canon 6D

Tronhard — Wed, 31 Jan 2024 19:56:46 GMT

If you are determined to invest your limited funds, then that is your choice. If it were me, I would save up for the right gear. But it's your decision and your money.

Re: Problems with extenders on canon 6D

Waddizzle — Wed, 31 Jan 2024 08:00:00 GMT

I also have a bad back, so I can relate to those related issues.

Stacking extenders is inadvisable, IMHO. The expected gains do not support the means. Download the manual and do a search for “lens groups” for a detailed explanation of how extenders and specific lenses work with your camera.

I understand that you are manual focusing, but your image quality will take a major hit. There is no substitute for having actual focal length in your lens.

Re: Extender EF 2X II - Stacked extenders produce black images on EOS 6D

ebiggs1 — Wed, 31 Jan 2024 15:47:03 GMT

"Stacking extenders is inadvisable, IMHO."

Mine too, in fact any 2x tel-con is not a good idea, IMHO. It is a fool's errand to spend your limited funds this way. Don't do it. Have you looked into a t-mount and a t-mount to Canon for your telescope? Way less than a single 2x te-con even a used one.

Re: Extender EF 2X II - Stacked extenders produce black images on EOS 6D

Waddizzle — Wed, 31 Jan 2024 19:44:59 GMT

Another issue with using 2x extenders is that you may get “ERROE 01” messages with certain lenses, Exp specially if you begin to stack them.

Again, there is no substitute for have a lens with the actual focal length you want or need.

Teleconverters are not cheap. Only certain models will work with certain combos of camera and lens. That is why I suggested that you download the manual and search for “lens groups”.

Re: Extender EF 2X II - Stacked extenders produce black images on EOS 6D

Waddizzle — Wed, 31 Jan 2024 19:54:58 GMT

@Starlight90 wrote:
Hello everyone,

I have a Canon 6D camera and 2 2x mk ll EF extenders, 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

If your screen is black, then you need to enable ExpSIM in the camera.

Re: Extender EF 2X II - Stacked extenders produce black images on EOS 6D

Tronhard — Wed, 31 Jan 2024 20:45:41 GMT

I suspect that the reason it's not working for viewing through the live view compared to the viewfinder is that one sees the image via the viewfinder with the aperture wide open, which is not how the image will be captured. Live view reads the image off the sensor with the aperture closed down.

My research indicates that the minimum f/stop with the 100-400L on the 6D is f/8. Each 2x extender added will cost 2 stops. So, with 2, 2x extenders that gives f/8 - f/11 - f/16 - f/22 - f/32! When looking at an essentially black universe at f/32 it's going to be black! So, to try to get a decent exposure one would have to crank up both the ISO and extend the shutter speed to a period where I would predict there is almost certain to be movement of the earth, resulting in star trails. That isn't even addressing the significant impact on the image from diffraction.

I am not an astro photographer, so if someone here is, can they confirm or correct this logic please?

Re: Extender EF 2X II - Stacked extenders produce black images on EOS 6D

Starlight90 — Wed, 31 Jan 2024 20:42:44 GMT

I don't use tel-con, I use the official canon 2x extenders. These are stackable. I won't use cheap knock offs unless they are recommended.

The tel-cons aren't compatible with L series lens

Re: Extender EF 2X II - Stacked extenders produce black images on EOS 6D

Starlight90 — Wed, 31 Jan 2024 20:43:47 GMT

I got no error code message. I use the official canon L series extenders

Re: Problems with extenders on canon 6D

Starlight90 — Wed, 31 Jan 2024 20:45:55 GMT

I have a printed manual for my camera

Re: Canon extender 2x mk ll on Canon 6D produces black images

Starlight90 — Wed, 31 Jan 2024 20:53:47 GMT

Thank you for all your replies, I shall go through each and everyone of them properly and determine my options.

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.

Re: Canon extender 2x mk ll on Canon 6D produces black images

Tronhard — Wed, 31 Jan 2024 20:58:13 GMT

I sympathize with your predicament. I really, really wish we could come up with some solution to your desire to use multiple extenders, but in all honesty, I see it as an investment that will not provide the results you want and will be a frustrating and costly effort.
Astro is a fairly specialized activity, and if you actually have the specific optic but need the adapter, then that would at least make use of your investment. If this is something you want to specialize in, and are prepared to relinquish other equipment for the right gear, that seems like a more sound proposal.

I really wish you all the best with this and hope you get a satisfactory outcome.