Focus Lock

Hi Im using a K20D and a K100D Super I am interested in doing some long exposures with ND Filters , can I lock the focus?

I would like to compose my scene then add my ND Filter without turning the lens focus ring , can I do this on the either of then ?
Thanks

Hmm, unless I have misunderstood your question but isn't that possible by focusing and then just moving the AF tab to MF and then attach the filters and then release the shutter? The focus wouldn't move again.

This is assuming your want to use AF to begin with.
Alternatively just use MF

Why the need to focus before adding filters? I doubt that the addition of filters is going to affect where the camera focuses, they will be too close to the front element.

But as Amin says simply swithc to MF after focusing

Sorry Im having a half a sleep moment sorry to waste your time Im thinking of My old Camera , thanks for wasting your time your time lol

If you have cokin p or lee filters you can focus before you slide the filter down in to place

james

Im going to be using a Welding Mask Glass that will be glued to an old filer less its glass , but I cant see through it at all ..
Thanks again

I wouldn't even think of putting even a good quality welding filter in front of a lens if I wanted good results. There's a reason why they cost 3 quid and ND filters cost 50 quid.

Can't you use the menus to you move the AF to the button at the back so that there is no AF when you press the shutter?

Usually I'd say I would be fascinated to see the results of a DIY experiment but not this time

Mike

Then again at a couple of quid it's a risk worth taking! Rather than buying ND filters for £50 and finding you don't use them very often.

Then I wont Bother showing you my test results I have so far and there is a reason why im doing it and not using my £38 ND filter

As I said before sorry to waste everyone's time including yours

I have seen shots taken with welders glass on other forums and they have been pretty damned good.

@Mike - Care to share an example? Not of the sun or an eclipse though

@Kurvz - no waste of time as it seems I am about to have my eyes opened and prejudices adjusted!

That said looking through my welders glass its simple diabolical.

Mike

Mike you'll get no argument from me. Off the Machine Mart for some welders glass it is then (all mine have splatter on them) except I hate MM and will go elsewhere rather than give them money, they upset me once.

Thanks to Kurvz for raising this.

Mike

There was a chap on Ebay selling welders glass ... he wasn't doing much trade up until the thread started on the forum. Hes now making a fortune

Dont know why you want an ND filter anyway, just wait for a typical english day and set the aperture to f32, take a flask and sandwiches though

Have I got hold of the wrong end of the stick on welders glass. This is the stuff you use to take out the UV and darken the weld. Usually rectangular and fits in the mask? Pretty thick and strong too.

This stuff?

Mike