GLSmith Loc: Tampa, Fl

step 1 figure out total weight of the 2 lenses individually as well as the weight of the camera
Step 2 Find a tripod of your choosing capable of supporting that weight & a few more...i.e. If camera & lens weigh 7 pounds, find a tripod capable of supporting a minimum of 12 pounds
When you buy it, immediately try it out...if you still have motion return it & get another vendor... I've had 2 different vendors I would not buy from again as I still get very minimal movement with a D850 & 600 mm telephoto
Keep in mind "wind", if its windy , you may want to remove the lens hood

Canisdirus

L plate and a fluid head.
Fluid heads don't slip.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

I think that you may be looking at this the wrong way.

Your tripod head is failing you. From your description, it sounds like the manner in which the camera is attached to the head is not all that great. Gimbals are really only used with lenses that have tripod collars, and you may end up spending between $80 to $150 for third party lens collars on eBay that may be of questionable quality. You will of course save the $$ you'd spend on an L Plate for the camera, but you haven't addressed the fundamental issue - a less than optimum tripod head.

The best solution, assuming you have a sturdy tripod, is to get a better head with an Arca-Swiss compatible clamp, and a rail so that you can move the camera back for better balance. Using an L bracket and an Arca-Swiss clamp on the rail to attach the camera will give you the flexibility in switching from portrait to landscape, and keep the camera from rotating. The rail should have a double dovetail so that it can be mounted on the head.

The next best solution is to use a rail on your existing head, but the reality is that if your head is insufficient, the rail will only provide modest benefit.

Hejnar Photo sells quality hardware and I am certain you can put together something with their rails and clamps. See my photos below. I used an 5/8" thick 8" double dovetail rail and a 1-1/2" Arca compatible clamp, mounted crosswise on the rail.

https://www.hejnarphotostore.com/

You could go with Bogen/Mafrotto, but it is less of an industry standard and though they have generic L brackets finding a rail that is made to Manfrotto's specs could be a problem. I've never tried looking but you may have better success.

On another note - if you are doing portrait work and you are not doing lots of repetitive headshots, using your camera hand held will provide a lot more flexibility. Using mono lights (preferable) or speedlights lights will keep your images crisp and sharp and free of camera or subject movement induced blur.

I realize none of this is within your budget, but not buying the right gear will only cost you way more than you planned to spend down the road. You already have a tripod and head that isn't cutting it. No point in repeating that mistake.

Rial mounted at mid-point

(Download)

rail mounted at front, camera fully to the rear

(Download)

rail mounted at rear, camera fully to the front

(Download)

camera rotated to portrait

(Download)

alberio Loc: Casa Grande AZ

If you oriented the tripod/head to where the weight of the camera/lens tightens the screw it might help. I've had similar issues and finally realized the screw was being loosened instead of tightened.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Using weight as a criterion for tripod selection will most certainly result in money wasted on junk. Nearly every tripod on the market today, even those made of aluminum with lots of plastic parts, will support a 12 lb load. But only a well designed tripod with thick legs will provide the stability required to keep the images free of motion blur. The fact you have already gotten two tripods that won't work with your 600mm lens should tell you all you have to know. With your D850 and 600mm I wouldn't use any tripod with a top tube diameter less than 37mm - and that is cutting it close. Thicker is better.

Image magnification - either by using a long lens at close range, or macro - is the most demanding of tripod stability. Load capacity really has nothing to do with stability.

https://blog.reallyrightstuff.com/choosing-a-tripod-part-1/
https://blog.reallyrightstuff.com/choosing-a-tripod-part-2/
https://blog.reallyrightstuff.com/choosing-a-tripod-part-3/

You don't have to bounce for RRS prices - you can get very reasonable performance from brands like Feisol, LeoFoto and others - but the key spec is top tube diameter.

imagemeister Loc: mid east Florida

Ultimately, the best you can do is keep the center of gravity of your lens/camera combo centered over the pivot point of your head (BALANCED). In your case, you will need an L bracket with a special adapter to allow using a long Arca/Swiss plate to allow for adjusting for this balance point. I cannot find the proper adapter right now but will post if/when I do .... Gene51 is showing the adapter plate you need in his response ...
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ecurb Loc: Metro Chicago Area

How about a visit to a hardware store and build your own L bracket and lens support bar? Look at Kirk and RRS websites for ideas.

petrochemist Loc: UK

Gimbals are great for long lenses, but are really not much use without a lens collar! the camera & lens need to be balanced for them to work.

With shorter lenses like your macro a decent ball head should hold the lens even without a collar.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Hejnar Photo has a great selection of plates, rails and clamps - and the rails come in a variety of thicknesses.

amfoto1 Loc: San Jose, Calif. USA

Neither of your lenses can be fitted with a truly functional lens collar.

And, to work properly, a gimbal should be paired up with a large lens that has a lens collar.

In other words, it's not "gimbal vs. lens collar"... It's gimbal AND lens collar. Your lenses have no means of fitting a collar AND aren't really large, long or heavy enough to handle properly on a gimbal. So neither a gimbal nor a lens collar is a solution to your problem.

To solve your problem, the easiest and best solution would simply be a better tripod head that holds better and doesn't slip.

If your tripod head uses Arca-Swiss type quick releases, it also might be possible to fit your camera with a long mounting plate that's aligned with the lens axis, rather than tangential to it the way camera plates are normally fitted. This would allow you to slide the camera backward slightly, to improve balance and equilibrium, reducing the tendency of the tripod head to drop.

Or, if you already have an Arca-Swiss camera plate on the bottom of your camera, get a Wimberley M-8 Perpendicular Bracket that fits onto the camera plate but protrudes forward, and will allow the same sliding adjustment for better balance on the tripod head.

Yet another possibility is a lens support. Kirk Photo offers a number of different ones (https://www.kirkphoto.com/catalogsearch/result/?cat=&q=lens+support) but they are lens-specific and none is made for Nikkor 28-300 or 105 Micro. You might find a more universal bracket of this type, but it may interfere with some functions of the lens, such as the manual focus or zoom rings. To be helpful, it too much be fitted with an Arca-compatible lens plate and allow for the whole rig to be slid backward atop the tripod for better balance.

You also might try using smaller, shorter prime lenses like 50mm f/1.4 and 85mm f/1.8 or f/2. These also have larger aperture than either the 28-300 or 105mm, so may be able to more strongly blur down backgrounds.

Personally I rarely use a tripod when I'm shooting portraits.
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kotography4u

All good thoughts and suggestions - thanks for responding with help! Lots to think about and plan for...
Kevin

RWR Loc: La Mesa, CA

No doubt that head, and probably the tripod, is too light duty. I shoot a lot of verticals and prefer a rotating collar, but four of my favorite heavy lenses have either a fixed bush or no tripod mount. I don’t care for L-brackets, so use heavy-duty ball heads and rotate the camera 90° clockwise (as seen from the rear). The forward weight of the lens thus tightens it against the quick-release plate screw and prevents sagging. With an appropriate tripod, off-center weight is not an issue. Good luck!

kotography4u

Thanks for the thoughts and tips - I hadn't thought about the trick of rotating the head clockwise so loosening of the camera wouldn't be an issue. I'll give it a try!
Kevin

Canisdirus

Just realize you are changing your framing of the image.

kotography4u

How so? Anything other than 180 degrees out?