Samyang 70-210 lens wo'nt auto focus on my camera.

Hi Bob.
This lens does´nt have an internal focus motor, this only works with an in-camera focus motor. So, if it is stuck after drop, there is a bend over the focus barrel. This means the manual focus will not work neither. If manual focus works normally, there an electronic problem at the PCB (broken element).

If the lens will focus on manual focus but won;t on auto focus you may have a ribbon connector failure in the lens. This ribbon continually flexis as the lens moves in and out. Over time this can break and will probably need to be replaced. All good camera repair shop should be able to do this for you and this remady is one of the cheaper repairs to photographic equipment

Unless you have a lens collimator and other gear needed to make sure you get the lens and mirrors aligned properly when you put it back together, don't even think about taking it apart. Take it to a reputable camera shop and have a trained professional do it.

If it focuses OK in manual but not in auto then you may have broken ribbon cable in the lens.

Make sure the auto-manual focus switch on your camera is set to auto (A) and also make sure the auto manual focus selector on the lens is in auto (A) as well. If your lens contacts are dirty then this will affect the function of the lens as well. Clean those with either a lint free type cloth and alcohol or methylated spirits.

if other auto-focus lenses work, then it is likely that this particular lens has a defect I suggest you send it in to Nikon for servicing

I could be that your lens isn't focusing. If the Auto focus can't find something to focus on the shutter won't fire. If you are shooting in low light sometimes it has trouble try shooting something that is well lit. also your auto focus point may be somewhere other than the center. there is a button on the top of your camera that looks like this [ ][ ] [ ] [ ]
More or less that will switch where your focus point is. If you look in the view finder and see a red dot when you push on the shutter button that is your focus point. push the above button until the red dot is in the centre. that may fix your problem.

If it is a auto focus lens the lens should be serviced and cleaned. If an auto focus lens gets dirty it gets stuck.

As long as the lens mount is compatible with the Olympus e410, you can use this lens.

It will only be limited by what features are supported through the camera body - I suspect that you will have to do everything manually.

Good luck.

A dirty filter, front, or rear optic can cause the lens to seek