How much weight can the EF lens mount handle?

[jrista]

I am about to purchase a CCD camera for my astrophotography. My hope is to still use the Canon EF 600mm f/4 L II lens, however the CCD camera is going to be a good deal heavier than a standard DSLR. My 5D III is about 2lb, the 1D X II is about 3.4lb.

Now the CCD camera itself is 3.5lb, however some additional accessories will be attached to it, including a filter wheel (with a bunch of filters) and an off-axis guider port. With those additional accessories, the weight could top 7lb.

Does anyone know how much weight the EF mount is rated to handle? Lens side? The 600mm lens is a very solidly built lens...however I need to make sure I don't rip the mount off the lens with this camera.

 

[bwud]

I doubt that information is published. You can for example hang your 600 f/4 from your camera body. Granted, that isn't putting the mount in shear, where it will certainly be weaker, but I'd not hesitate to hang a 5# load off a supertele.

 

[Don Haines]

I tend to be a wee bit paranoid about those things..... Do you the ability to create a custom bracket that will attach to both the lens collar and the camera's tripod mount?

 

[neuroanatomist]

I don't know that anyone outside of Canon would know an actual spec. I've had close to 6 lbs on the mount of my 600/4 II (2xIII, 1D X with RRS L bracket, 600EX-RT). The C500 setup is 6.4 lbs, I'm sure Canon is aware it will be used on collared lenses. That's constant weight – short term, I've lifted the 600 II by picking up the attached 1D X.

I think you'll be fine. Looking forward to the resulting images!

 

[9VIII]

How deep is the new body?

You may be able to hang a Big White off the mount when the lens is facing down, but trying to hold it level would probably be disastrous. The 1Dx weighs a lot, but it only extends a few inches from the mount so it's still mostly a downward pressure. The further your body hangs from the mount the more worried I would be.

 

[Mt Spokane Photography]

I doubt that there would be a issue with 5 lbs hanging on the lens. At 10 lbs, I'd begin getting worried. The issue would be spring the mount on either the camera or the lens such that one side was out of focus. I don't think there would be a permanent set unless there was a lot more weight. There is a lot of safety margin, dropping a camera with a heavy lens is usually where we see mount damage.

 

[jrista]

Thanks guys. The camera will most likely be a Moravian G3-16200, although other options are the SBIG STXL-16200 or FLI ML16200. The latter is least likely, would be about ten grand to get the full kit, and I just don't think I can afford that. The SBIG would be over eight grand. The Moravian would be at most $5700, maybe as little as $5100 (don't know how they are pulling off that deal...but they are.)

I am not yet sure if I'll be using the Moravian 7-pos filter wheel with their OAG, or the Starlite Express 9-pos FW. The 9-pos FW is ~3.5lb on it's own, the camera another 3.5lb. So that's 7lb right there.

I don't think I would get up to 10lb, probably not even 9lb...but it might be over 7lb with some additional accessories.

 

[neuroanatomist]

What about using a RRS long lens support (or something modified from it), mounted backward?

http://www.reallyrightstuff.com/Lens-Support-Pkg-dual-Quick-Release

 

[9VIII]

Thinking along those lines.
I don't know how clean you want it to look, but just buying a super long lensplate and taping a block of wood to the back to hold the body up would probably work pretty well.

 

[jrista]

I don't know that a simple block of wood is going to do it. Keep in mind, I'll be tracking across the sky, and the lens +camera can swing from the eastern horizon (more "flat") to the meridian (more "upright"), after which it would experience a meridian flip where the mount reorients to point from the meridian and track down towards the western horizon.

So the force of gravity on the camera is going to change with time, which in turn will change the force on the mount. It won't simply be down towards the bottom of the lens, like when your holding the lens for wildlife or sports. It entirely depends on where in the sky I am pointing, and how long I image for. I could have just about any orientation to find anything within the 180 degree hemisphere of the sky.

For reference, here is the setup I use for the 600mm lens:

 

[AlanF]

Is the camouflage for not scaring off extra-terrestrials?

 

[Bennymiata]

Camouflage?
What camouflage?
I can't see it.

Impressive set-up there.

 

[jrista]

Is the camouflage for not scaring off extra-terrestrials?

'tis indeed. You would be surprised how many Romulan Warbirds and Klingon Birds of Prey and often even more exotic "spacecraft" show up in astro images. ;P (Just search around...you'll see what I mean. ;D)

That, and keeping the lenscoat on has prevented my lens from having the hell scratched out of it through all the travel to and from my dark site, from the scope rings clamping down, etc. It's a $12,000 lens...gotta protect the investment.

 

[zim]

Wow that setup looks like a lot of fun!

And that big flat plate with spare holes in looks ripe for an angle extension back to the camera base no?

 

[brad-man]

I would also think that the mount would be strong enough to handle the stress, but perhaps you could bolt something like this to the back of your 4x12" plate for additional support:

http://www.amazon.com/Haoge-Telephoto-Long-focus-Compatible-Sunwayfoto/dp/B00ZVI7S2E/ref=sr_1_27?s=photo&ie=UTF8&qid=1459081957&sr=1-27&keywords=lens+rail

Good luck!

 

[Busted Knuckles]

I would also think that the mount would be strong enough to handle the stress, but perhaps you could bolt something like this to the back of your 4x12" plate for additional support:

http://www.amazon.com/Haoge-Telephoto-Long-focus-Compatible-Sunwayfoto/dp/B00ZVI7S2E/ref=sr_1_27?s=photo&ie=UTF8&qid=1459081957&sr=1-27&keywords=lens+rail

Good luck!

I like this idea - it could take up some of those washers/spacers on the camera end of the plate.

Then again, I have -0- experience with the kind of image making you are doing. I was thinking it might work well for my panorama efforts, be able to nodal point a longer tele.

Happy clicks

Mike

 

[Deleted member 91053]

I am about to purchase a CCD camera for my astrophotography. My hope is to still use the Canon EF 600mm f/4 L II lens, however the CCD camera is going to be a good deal heavier than a standard DSLR. My 5D III is about 2lb, the 1D X II is about 3.4lb.

Now the CCD camera itself is 3.5lb, however some additional accessories will be attached to it, including a filter wheel (with a bunch of filters) and an off-axis guider port. With those additional accessories, the weight could top 7lb.

Does anyone know how much weight the EF mount is rated to handle? Lens side? The 600mm lens is a very solidly built lens...however I need to make sure I don't rip the mount off the lens with this camera.

The EF mount is quite capable of lifting lenses (vertically I haven't been brave enough to try horizontally) of over 6 kilos - it is what it was designed for. Also the C100 Mk2 (EF mount) can weigh just under 2 Kilos so you should have no problems at all.

 

[JMZawodny]

Thanks guys. The camera will most likely be a Moravian G3-16200, although other options are the SBIG STXL-16200 or FLI ML16200. The latter is least likely, would be about ten grand to get the full kit, and I just don't think I can afford that. The SBIG would be over eight grand. The Moravian would be at most $5700, maybe as little as $5100 (don't know how they are pulling off that deal...but they are.)

I am not yet sure if I'll be using the Moravian 7-pos filter wheel with their OAG, or the Starlite Express 9-pos FW. The 9-pos FW is ~3.5lb on it's own, the camera another 3.5lb. So that's 7lb right there.

I don't think I would get up to 10lb, probably not even 9lb...but it might be over 7lb with some additional accessories.

A little late to the party here, but I love my FLI. I think you'd really enjoy that camera.

 

[PeterAlex7]

If the tripod collar also included that means the lens weight can destroy the mount.

 

[jrista]

I am about to purchase a CCD camera for my astrophotography. My hope is to still use the Canon EF 600mm f/4 L II lens, however the CCD camera is going to be a good deal heavier than a standard DSLR. My 5D III is about 2lb, the 1D X II is about 3.4lb.

Now the CCD camera itself is 3.5lb, however some additional accessories will be attached to it, including a filter wheel (with a bunch of filters) and an off-axis guider port. With those additional accessories, the weight could top 7lb.

Does anyone know how much weight the EF mount is rated to handle? Lens side? The 600mm lens is a very solidly built lens...however I need to make sure I don't rip the mount off the lens with this camera.

The EF mount is quite capable of lifting lenses (vertically I haven't been brave enough to try horizontally) of over 6 kilos - it is what it was designed for. Also the C100 Mk2 (EF mount) can weigh just under 2 Kilos so you should have no problems at all.

Yeah, I am not worried about vertical lifting. I lift my 600mm lens with my 5D III when the lens is pointed strait towards the ground. The application here is the lens holding the camera horizontally. The lens, as you can see from my photos, is very well held, extremely rigid. So the entire weight of the camera, filter wheel, and filters (which are about 4.2oz each, and I will have 7 of them, so another 1.85lb on top of the camera and FW themselves) is going to be hanging off the lens.

In my case, it will probably be about 6.5-7lb, which is around 3kg or more. So far, I have not found any camera that weighs nearly this much. I've tried accounting for some accessories, like flash and diffusers and maybe a wifi adapter. Still doesn't amount to as much weight as I am looking to use.

I think I will need to find some way to support the camera off the dovetail. That is not as easy as it sounds, though. The filter wheels are very large. They hang down below the camera as well, and I don't think I could extend the dovetail all the way back to the camera body. I don't think I could use any of the accessories that have helpfully been linked so far, either, sadly.

I may have to design something of my own to handle this, and at least take some of the weight off the mount. I really want to be able to do LRGB and narrow band imaging with this lens, as it's phenomenal for astrophotography. But it also costs as much as a small car...and I don't really want to buy this particular camera until I know for sure I can actually use it on this lens.