[soccerjoe5]

No way. I never would use my 055 with such a load. I imagine that a lens of that weight will also excert considerable torque.

I would buy a used big Gitzo aluminium tripod (my old Gitzo Studex would probably be too small) . Alternatively wooden tripods would be a good choice, either dedicated photo modells by Berlebach, Wolf etc. or surveyors tripods, but these are really heavy (have one for a telescope...)

You will have more of a headache when it comes to a good tripod head for such a lens. I would either use a gimbal mount or a really good video head. Video heads are considerably cheaper than photo heads, as they have one axis less (2D instead of 3D), but heavy lenses are usually rotated in their mounting ring to switch between landscape and portrait format, so the third axis is not necessary. Otherwise the big Manfrotto gear driven head might be good choice.

While writing about video heads: a video tripod might also be a good choice - obviously not of the small variety...

Ben

I believe the Markins M10/20 and the RRS BH-55 can handle the lens dadipentak will be using Here are the tests and the M10 handling the Nikkor 800mm with ease:

http://www.markinsamerica.com/downloads/load_test_high.wmv
http://www.markinsamerica.com/downloads/nikon_800mm_high.wmv

The wimberley sidekick or gimbal head are good choices too.

[Ben_Edict]

I use a Zone VI tripod under a Wimberley head for my 600mm lens. I have no reason to think I might have too much tripod for this lens.
My 055 tried to collapse under the weight of my Pentax 6x7 and 105mm lens one day. I've been very wary of putting anything even remotely heavy on it ever since.

Though a 055 shouldn't be that bad (you can re-adjust the clamping screws), you're Zone VI tripod seems to be a superior choice.

Ben

[Ben_Edict]

I use a Bogen 3421 fork mount on a Bogen 3246 tripod on everything from 500-1000mm and it works for me.

Yes, the cheap Manfrotto/Bogen gimbal head is a nice contraption. I use it with the Pentax 500/4.5 and the Meyer Optik 500/5.6 (medium format) + tcs nicely.

How does your focuser cope with such a long behind (first image)? I imagine some problems with stiffness and centering, but you've probably got a solution for that.

Ben

[wildman]

How does your focuser cope with such a long behind (first image)? I imagine some problems with stiffness and centering, but you've probably got a solution for that.Ben

The first pic is a somewhat unfortunate choice.
This was setup for extreme close-up work (10-20 feet) so there is much more extension in this pic than I normally use.

But to your question - I think you are asking about keeping the focal plane of the camera in collimation with the scopes optics. If so I have a laser collimator that allows me to check this and keep things up to snuff. Also the dual speed Crayford focusers allow for this adjustment and are very robust and run on adjustable ball bearings.

This is a more typical setup...

---

Last edited by wildman; 02-23-2009 at 05:02 AM.

[Ben_Edict]

But to your question - I think you are asking about keeping the focal plane of the camera in collimation with the scopes optics. If so I have a laser collimator that allows me to check this and keep things up to snuff. Also the dual speed Crayford focusers allow for this adjustment and are very robust and run on adjustable ball bearings.

So, the standard Astrotech focuser can take that much of a load - looks good, then. I thought you need something like a Feathertouch with these long extension tubes on the back.

Ben

[wildman]

Ben,
I just added this to my scopes:
William Optics - FLT 98

Take a look at the focuser on this one - it sure should handle a K20 with a 100mm of extension without losing collimation.

[Ben_Edict]

Ben,
I just added this to my scopes:
William Optics - FLT 98

Take a look at the focuser on this one - it sure should handle a K20 with a 100mm of extension without losing collimation.

Yes, this focuser is enormous, 3.5 inch... Good enough for a 645. I have one of the smaller 2-inch modells on one of my Cassegrainians and this WO products are really nicely made.

Ben

[dadipentak]

Hmm. So far I'm pretty pleased with the Manfrotto set-up (described above)--at least for now. The price was right (<$300), it seems quite sturdy and it's really very manageable. Here a shot of the rig (yeah, it's a bad background for the subject--sorry about that.)

Manual focusing does make the lens wiggle a bit (side to side) and I have to wait a second or two before hitting the remote but that seems to be more a function of the length of the lens (29 inches or 738mm) than its weight. It doesn't bother me much right now while I'm getting the hang of shooting a big MF lens in manual mode but I'm sure I'll lose patience with that very quickly when I try shooting skittish birds. I'm going to try some jury-rig arrangements to mitigate that issue.

[Peter Zack]

Dave never ever take that anywhere near a Federal Building!! We'll have to send you postcards in Cuba...

As for the wiggle, You could get a bean bag or better yet a 3-5 lb sandbag (exercise shops have those wrist and angle ones with velcro) and try putting it over the lens right above the mount. That should absorb the vibration to some extent. A nice big bean bag would also be good to use instead of a tripod out in the field. You could use it on a fence post or other solid object.

I think at some point you are going to have to consider adding a gimbal to the tripod.

[Wheatfield]

Hmm. So far I'm pretty pleased with the Manfrotto set-up (described above)--at least for now. The price was right (<$300), it seems quite sturdy and it's really very manageable. Here a shot of the rig (yeah, it's a bad background for the subject--sorry about that.)

Manual focusing does make the lens wiggle a bit (side to side) and I have to wait a second or two before hitting the remote but that seems to be more a function of the length of the lens (29 inches or 738mm) than its weight. It doesn't bother me much right now while I'm getting the hang of shooting a big MF lens in manual mode but I'm sure I'll lose patience with that very quickly when I try shooting skittish birds. I'm going to try some jury-rig arrangements to mitigate that issue.

A couple of things to try:
After the tripod is set up, string a bungee cord around the legs just below the top locks. It doesn't need to be taught, just snug.

Attach a 1/4x20 eye bolt to the tripod socket of your camera. Attach a bungee cord from the eye bolt to the bungee around the tripod legs, again snug, but not very tight.

This will eliminate a whole lot of shakin.

Also, even resting your arm lightly across the lens when you push the button can dampen vibration a lot.

[dadipentak]

I'm so proud of myself--I had thought of both of those strategies, Peter & Wheatfield! It's great to know they make sense to you as well. Thanks!

[wildman]

Manual focusing does make the lens wiggle a bit (side to side) and I have to wait a second or two before hitting the remote but that seems to be more a function of the length of the lens (29 inches or 738mm) than its weight. .

As length gets very long you might want to consider using at least a two point mount on the scope tube - it can be a big help in damping down harmonic vibrations from wind or simply handling the camera. That long tube can start ringing like a bell under certain conditions...

[dadipentak]

That's a cool set-up, wildman--looks like it would solve my problem. Is it commercially available? [Winces] Looks like it might be expensive.

[Ben_Edict]

That's a cool set-up, wildman--looks like it would solve my problem. Is it commercially available? [Winces] Looks like it might be expensive.

What you need is the gimbal mount (the Manfrotto/Bogen in this case) and then two tube rings. THese are commercially available in a variety of diameters from astronomy dealers. The two tube rings are connected with a dove tail plate, which is also available in different lengthes to suite your needs.

Ben

[dadipentak]

Thanks, Ben--I'll file that for future reference. I'll admit that my one concern is that my set-up relies on a single-bolt QR plate attachment. It's a substantial bolt, to be sure, but still, I'd prefer a bit of redundancy.