Metabones Speedbooster Problem - Please Help

[Peter Rush]

SO yesterday at the start of the wedding speeches I had a panic as I couldn't focus properly - I quickly worked out if I zoomed in my 24-105mm Canon lens I could achieve focus but if I zoomed out any more I lost focus completely.

I struggled on as I was in no position (monopod and tightly packed tables) to get a replacement lens but when I finally got time I tried my other EF lenses and the problem was the same so I'm putting it down to the adapter - anyone else come across this?

I rely on this adapter so need to act fast.

Pete

[Peter Rush]

Stop Press - Problem solved - the 4 tiny screws on the plate (the side that attaches to the camera) were loose - even though there was no rotational play, tightening them up has done the trick - phew!

[Jody Arnott]

I had the same problem with my Metabones adapter. I was on a shoot, and I couldn't focus properly with my 11-16 lens. I got rather stressed as I couldn't figure out what was going on.
It wasn't until I got back to the office that I noticed the screws were loose, and there was noticeable play in the adapter plates.

Just one of many problems I've had with my Metabones adapter.

[Chris Harding]

Hi Guys

Maybe a tiny lick of Loctite on the threads would solve the loose screws issue? That should keep them from coming loose all the time? I wonder what makes them come out ..surely there is no movement and vibration on the adapter ??

Chris

[Jody Arnott]

Originally Posted by Chris Harding

Hi Guys

Maybe a tiny lick of Loctite on the threads would solve the loose screws issue? That should keep them from coming loose all the time? I wonder what makes them come out ..surely there is no movement and vibration on the adapter ??

Chris

Mine came out the first day I used it, so I would say it comes down to bad quality control.

[Chris Harding]

That's really disgusting considering how much you pay for the adapter and their service isn't the greatest either! I'm surprised that some decent manufacturers haven't built a Smart adapter!!

If the screws keep coming loose then I would definitely undo them, put just a drop of Loctite on the thread and screw them back in and they won't come out on their own again but you can still unscrew them if you had to.

Chris

[Bob Hart]

Take care with that Loctite trick. The hex shaped holes in the fasteners are inclined to tear out if you are not careful and leave you with unscrewable screws.

That said, I doubt you will want to take the front or rear mount rings off once they are fixed unless the mount gets a bellyful of water or grit. However if a movement develops and the surfaces begin to polish, you will want to be able to re-tighten those screws.

You may be better served by addressing the cause, movement of the mounts against the body through normal mounting and dismounting of lenses, especially if those mounts are a bit tight.

A few pinspots and no more of Loctite on the mount-to-body contact surfaces should limit the movement which wears away high spots in the machining finish, reduces tension on the screws which then loosen.

I found that the M4/3 mount ring on the rear was a bindingly tight fit on a BMPCC camera to the point of concern for damage to the camera. That sort of torsion will move a mount, polish surfaces and loosen screws. There is no wedge shape or taper on the corners of the lugs.

The edges of the screw countersink holes are also apparently sharp. Given these are chromed brass, the hard sharp corners may will be digging into the metal they contact to cause that "grating" feel as the adaptor is turned in the mount.

I found that dressing the corners with a bit of wet and dry silicon carbide paper in the 800 - 1200 grit range helped to smooth the mount-dismount. Take care not to dress the entire flange face or the collimation may go off or the mount, however tight, may rock on a high spot causing image shift with long lenses.

You will wear through the thin chrome plating on the sharp corners, therefore it won't look so pretty any more.

Do not do any dressing of surfaces with the mount ring attached to the adaptor. Wash it scrupulously clean and dry before refitting. Loose silicon carbide and chromeplate particles are lethal to optical glass and coatings. That optical group is a sweet piece of precision work. It would be a pity to damage it.

You may be able to achieve the same objective with a rotating fine wire brush on a drill or bench machine.

Just watch your fingers and wear safety glasses. Mount rings catch in wire buffs on bench grinders, pull your finger in if you are not careful and fly cruelly.

[Peter Rush]

To be honest guys I've had this adapter over a year and it's had a lot of use and this is the first issue I've had with it. I also have a Metabones EF - NEX Smart Adapter for my Sony A7s and I was getting exposure flashes as I adjusted the iris - Metabones got back to me within a day with the reason and the fix (reset the adapter to advanced mode) so I can't really fault them.

Pete

[Craig Marshall]

My Zeiss to NEX Speed Booster has a backfocus adjustment and it is critical that it be correctly set up with the lens wide open. Accurate backfocus setup is mandatory with these adapters especially to calibrate the lens' witness marks.

Associated reading: How to Test the Backfocus of Film and Video Cameras - The Black and Blue | The Black and Blue