Focus trap

[robar]

to get this to work with M42 lens i have to short out the contacts on the lens with aluminum foil.

question is,, will this hurt the camera. i would assume , NO, as they must be shorted out when using a K or M lens.

roy

[danielchtong]

robar wrote:

to get this to work with M42 lens i have to short out the contacts on the lens with aluminum foil.

question is,, will this hurt the camera. i would assume , NO, as they must be shorted out when using a K or M lens.

roy

Contacts on m42 lens?

Daniel

[bigdawg]

Contacts on the camera Daniel. Roy I don't think this will hurt anything as some of my modified lens short it out as well.

Dawg

[John Hill]

I tried to get this matter figured out. As far as I can tell the requirement is to short one camera pin to the frame of the camera. This pin is the third pin from the high end and on the camera it is depressed, it is the only depressed pin.

This is necessary on my *ist DS to get focus trap but it is not enough. It will only work with the camera on the green "Auto Pict" setting but few of my pictures have satisfactory exposure which I presume is due to the camera 'thinking' this is lens set on the 'A' setting. The camera tries to stop the lens down but of course it cant and all shots are somewhate, or exceedingly overexposed.

I am not saying it is impossible, just that I have not yet found the magic combination of camera settings

[robar]

this worked well with my super tak300/4. it's little inconsistant with the viv200/3.5.. maybe i don't have the cotacts shorted enough..

[robar]

FT works all the time on my K/M lenses. it did not on the tak500/4.5 untill i canged the K mount the a newer one. it works perfectly now. this mount has a metal base as the other one did not.. guess i need tou go to the lake again.

roy

[jachol]

Now there's coincidence Roy, I just completed this a little while ago ... Someone (Gumnut I think) suggested a foil shim washer between the lens and the body. My first attempt I used ordinary kitchen cooking foil, but found it to be too flimsy and too thin, it was a bit iffy in use some times works others no. The final one is made from a foil pie container (Eat the pie first ). :lol:. This is thicker (not enough to affect infinity focus) and stronger, it works well. While the lenses I'm using are metal, I think they have an anodised coating which seems to be nonconductive. I'm making one for each M42 lens, it can stay on its own lens secured by the rear cap, and each lens has it's own container, so it's unlikely to get damaged or lost. The picture below shows it in place on my Vivitar M42 90mm/2.8 Macro lens. Will need to buy more pies tomorrow :G. BTW Gumnut if it was you, it's an excellent suggestion !.... Jack

[robar]

i've got all contacts shorted with heavy weight kitchen foil.
FT works in all mode , Av,M,T,P and Autopic. i did not ck the scene modes.

i'll bet you could take some sand paper and remove the anodized area on the lens.

roy

[jachol]

robar wrote:

i'll bet you could take some sand paper and remove the anodized area on the lens.

roy

I'm sure you can, but this doesn't affect the lens resale value in any way. I haven't checked other modes yet, mainly use manual anyway. ... Jack