[germar]

Folks:

I have happily used a wide range of screwmount lenses on my K10D with no issues. I've just taken ownership of a beautiful Takumar 300/4 that weighs about 1350 grams, the biggest and heaviest lens I've ever owned. I will be attaching it to a K10D with a battery pack, so the whole thing is suitable for a weightlifting working out.

The lens has a tripod mount, so I can balance the entire rig, but I have my doubts about stressing the Pentax M42 adapter with SO MUCH weight. Any advice, and experiences with really heavy lenses? I am using a genuine Pentax adapter, but I also have the "Bower" brand from B&H which is heavier metal but requires a tool for removal.

Any feedback about heavy weight hanging off this little adapter ring?

much thanks,

germar

[Zewrak]

I have been running around the forests with the lens mounted to the camera in a R-Strap attached to the camera. Without noticing any problems. The tripodmount weight alot by itself, so remove it if your going to do it for a long time i guess.

I have probably had it mounted and running around for 30 hours or so total without any problems at all. Ofcourse, if you have a strap that can be mounted on the tripod mount (such as the R-Strap), you should. But I do not think that you have to worry too much.

[Jimfear]

I don't think there is any big risks in this. The adapter sits tight on the lens so it's basically the same as a K-mount lens. And the mount can probably hold a lot of weight. I have not had any problems with my 450mm lens that also puts a lot of strain on the mount and adapter.

I wonder what brakes first though, does the metal on the lens bend or break or does the whole mount come of the camera? Any thoughts on this?

[Zewrak]

I wonder what brakes first though, does the metal on the lens bend or break or does the whole mount come of the camera? Any thoughts on this?

I doubt anything will bend, possibly that the mount on the lens (in this case the adapter) will get grinded down so that it does not fit anymore. The mount on the camera is very firmly stuck in the entire chassis inside the camera which is steel and will not break for such small weights. You could probably mount a hook in it and hang in it with your bodyweight.

I also doubt that the m42 thread will break for such little weight. So the weak link would be the flanges on the adapter. Which on the genuine (cant speak for others) seem strong enough to hold for quite a weight. Only if the edges on it was grinded down thru wear, I think it would be a risk for the lens. But hopefully, if that happens you will notice it far in advance.

So, just check the adapter and m42 threads now and then and I am sure youll be fine. And the old takumars are tanks, if you manage by force to bend the barrel of a Takumar, I will be impressed of your muscle mass.

[Wheatfield]

If you put too much weight on the mount you can warp the chassis of the camera. I wouldn't be supporting a 3 pound lens by the camera body myself, but then, that's just me.

[stevebrot]

I think the capacity may vary depending on the brand of adapter. Some of them have rather small "ears" for engaging the body. Materials also vary. Some are chromed brass, some are aluminum, and others are stainless steel.

Steve

[Gooshin]

Folks:

I have happily used a wide range of screwmount lenses on my K10D with no issues. I've just taken ownership of a beautiful Takumar 300/4 that weighs about 1350 grams, the biggest and heaviest lens I've ever owned. I will be attaching it to a K10D with a battery pack, so the whole thing is suitable for a weightlifting working out.

The lens has a tripod mount, so I can balance the entire rig, but I have my doubts about stressing the Pentax M42 adapter with SO MUCH weight. Any advice, and experiences with really heavy lenses? I am using a genuine Pentax adapter, but I also have the "Bower" brand from B&H which is heavier metal but requires a tool for removal.

Any feedback about heavy weight hanging off this little adapter ring?

much thanks,

germar

This is why you should utilize your lens's tripod mount! That way the camera is only supporting itself.

If you are machine gunning it, simply hold the barrel with your other hand (although i cant imagine you holding this thing otherwise)

so really dont worry, just dont lift by the body and you'll be fine.

[newarts]

I think the first thing to fail might be the screws holding the mount receiver plate to the camera. That'd take a LOT of force.
Dave

[Peter_JDH]

Since this question was first posed here, has anyone ever actually damaged a lens/camera/M42 adapter owing to the weight of the lens?

[swanlefitte]

My 300 f/4 will simply snap the adapter out without damaging anything as long as you catch the lens.

[mlag]

I don't think there is any big risks in this. The adapter sits tight on the lens so it's basically the same as a K-mount lens. And the mount can probably hold a lot of weight. I have not had any problems with my 450mm lens that also puts a lot of strain on the mount and adapter.

I wonder what brakes first though, does the metal on the lens bend or break or does the whole mount come of the camera? Any thoughts on this?

With my biggest lenses like pentax 150-450, bigma 50-500mm, ...whenever the lens gets heavier than the camera, I typically carry the lens(@ tripod mount) and let the camera hang onto the lens... the neck strap around wrist for extra backup. For longer hikes it goes into the backpack.