Good evening, I have bought a Canon EF 50mm f/1.8 Mark ii lens to use with my Canon 5d Mark ii camera, and I have problems using it: - after mounting it, and switching on the camera, I have no problem using it, with or without the auto-focus, and take a first shot, - once I have taken the first shot with ViewFinder, ViewFinder goes all black, and the only way i can take further shots is via LiveView mode only. this is quite annoying, and I am not sure where this comes from. If I unmount the lens and remount it, the same happens: I can take one shot with ViewFinder but then only with LiveView. This doesn't happen with any of my other lenses (24-105mm, 17-40mm, 70-200mm) Any help on this matter would be greatly appreciated.

Have a look here

http://www.canon.co.uk/support/consumer_products/product_ranges/cameras/eos/error_codes/#err01

Seems to be a connection problem Clean to connectors on both the lens and camera with a pencil eraser.

If the Sigma lens mount is a Canon FD fitting then you can get an adapter FD to EF that will allow you to use the old lens in manual mode. If your camera isn't designed to take EF-s lenses then they will not fit on the camera. My EF-s lenses will not fit on my 6D.

You can use Canon EF lenses. Be careful not to use EF-S lenses, as they cast a smaller image circle for cropped-sensor cameras, not big enough for full-frame cameras.There are other third-party manufacturers that make lenses with Canon EF mounts, such as Sigma and Tamron. Each manufacturer has their own designation for cropped-sensor lenses, so you'll have to check the specifications for each of them.

I understand there isn't a manual, just a quick how-to guide. Here's some basic use info from a review
http://www.the-digital-picture.com/reviews/canon-bg-e6-battery-grip-review.aspx

The Canon BG-E6 Battery Grip is designed specifically for the Canon EOS 5D Mark II as shown above with a Canon EF 16-35mm f/2.8 L II USM Lens mounted. To get the Canon BG-E6 Battery Grip into the position shown, the LP-E6 Battery is removed from the 5D II and the battery door detaches. The BG-E6 slides up into the battery compartment and locks into place via the tripod socket screw seen on the BG-E6 just below the lens in the above image. The BG-E6 provides its own tripod adapter threads - this functionality is not lost.

The Canon BG-E6 Battery Grip holds two Canon LP-E6 Batteries that deliver double the number of shots or video time from the 5D II. Alternatively, use 6 AA batteries in the included Canon BGM-E6 Battery Magazine shown below.

Do you find that if you slightly loosen your lens you hear a click or something releasing. Then when you lock the lens back into place u can see through the view finder, but only for 1 photo. Then it stays black again?

I don't think so. the lens is held by 3 or 4 internal plastic hook clipping type . send it to canon cost about 30 bucks. one clip breaks, you can say goodbye to your lens.

Maybe that's why it was for sale on Ebay.

I had the same problem with my ef 50mm 1.8. I used it on a cold day and broke off one of the internal gears. I used it for almost a year before I got the guts to take it apart and fix it. There are instructions online on how to take it apart, scary at first but not that hard overall. I used a small drop of crazy glue on the gear, put it all back together and just like new.

You need to send it in for service. The more you use it with the "noise", the more you are potentially damaging the auto-focus drive mechanism of the lens. The sound you are hearing is most likely the gears and whatnot grinding away at each other because they were knocked out of place by the impact of the fall. I don't know how much this will cost, but I would say somewhere in the $200 range would not be unbelievable. Sorry I don't have any good news, but I have "bounced" a lens or two in my time.

By the way are these RAW images? What type of lense are you actually using, check this

EOS-1Ds Mark III EOS-1D Mark III EOS-1D Mark II N
EOS-1Ds Mark II EOS-1D Mark II EOS-1Ds
EOS-1D EOS 5D EOS 40D
EOS 30D EOS DIGITAL REBEL XSi/EOS 450D EOS DIGITAL REBEL XTi/EOS 400D DIGITAL
Compatible Lenses
EF 14mm f/2.8L USM EF 28-70mm f/2.8L USM
EF 14mm f/2.8L II USM EF 28-135mm f/3.5-5.6 IS USM
EF 20mm f/2.8 USM EF 28-200mm f/3.5-5.6
EF 24mm f/1.4L USM EF 28-200mm f/3.5-5.6 USM
EF 28mm f/1.8 USM EF 28-300mm f/3.5-5.6L IS USM
EF 35mm f/1.4L USM EF 70-200mm f/2.8L USM
EF 50mm f/1.2L USM EF 70-200mm f/4L USM
EF 50mm f/1.4 USM EF 70-200mm f/2.8L IS USM
EF 85mm f/1.2L USM EF 70-200mm f/4L IS USM
EF 85mm f/1.2L II USM EF 100-400mm f/4.5-5.6L IS USM
EF 100mm f/2.8 Macro USM EF-S 60mm f/2.8 Macro USM
EF 135mm f/2L USM EF-S 10-22mm f/3.5-4.5 USM
EF 180mm f/3.5L Macro USM EF-S 17-55mm f/2.8 IS USM
EF 200mm f/2.8L USM EF-S 17-85mm f/4-5.6 USM
EF 200mm f/2.8L II USM EF-S 18-55mm f/3.5-5.6
EF 16-35mm f/2.8L USM EF-S 18-55mm f/3.5-5.6 II
EF 16-35mm f/2.8L II USM EF-S 18-55mm f/3.5-5.6 USM
EF 17-35mm f/2.8L USM EF-S 18-55mm f/3.5-5.6 II USM
EF 17-40mm f/4L USM EF-S 18-55mm f/3.5-5.6 IS
EF 24-70mm f/2.8L USM EF-S 55-250mm f/4-5.6 IS
EF 24-105mm f/4L IS USM -