shimming the J3 down to .6m close focus

[ampguy]

Well I decided to double up my shim with another credit card ring stacked with the previous one that got me to about .8m focus. Although I doubled the shimming distance, and am probalby at about 1.3 - 1.5mm total shim thickness (between the lens and ltm adapter), I'm accurately focusing at 24" or .60m.

This is based on Lynn and Brians initial shim project.

Distortion is low, and images look very good in the center, I haven't pixel peeped corners yet.

It does affect far focusing though, which used to be 8-10 feet, is now about 5 feet, which makes sense.

Anyone else using doing any shim experiments this weekend?

 

[Sonnar Brian]

Just the usual shimming of lenses for accurate close-up and wide-open.

But I saw an Ebay shot of a guy that converted a Nokton 50/1.5 to M-Mount using a Summicron Focus Mount...

 

[ampguy]

interesting

interesting

Was that just to remove the need for an ltm to m adapter, or did it include some close focusing as well?

Just the usual shimming of lenses for accurate close-up and wide-open.

But I saw an Ebay shot of a guy that converted a Nokton 50/1.5 to M-Mount using a Summicron Focus Mount...

 

[Sonnar Brian]

The Nokton is in Voigtlander Bayonet mount, this was the 1950s lens. I have two of them, use one with an adapter for S-Mount. I want to make one of them into LTM or M-Mount.

 

[ampguy]

One of the advantages to limiting your far distance is that your focus throw now has much more of a longer throw over the focus range, giving you focus control and precision that you could likely never achieve with a lens that focused further out:

 

[johannielscom]

Of course focus can only be checked when chimping on a digital camera, am I correct? The RF cam on M8 and M9 does not follow a lens down to .6 mtrs, does it?

 

[Sonnar Brian]

Moving the entire lens out means that the threads will not block the RF pickup of the camera from following the Cam of the lens. It will go out to full extent. I suspect the 0.7m has some margin to it, and might be possible to go slightly closer using this method. Take the lens off of your camera and test how close you can get to an object. This is the minimum focus that can be realized with the shim under the lens method.

 

[ampguy]

It's good at .6m / 24"

It's good at .6m / 24"

On my m8, surprisingly I stay coupled. I might try a 3rd shim which I would expect to lose coupling, but maybe get to .5m close focus point today or tomorrow.

Of course focus can only be checked when chimping on a digital camera, am I correct? The RF cam on M8 and M9 does not follow a lens down to .6 mtrs, does it?

 

[ampguy]

OK, with a 3rd shim, somewhere north of 1.5mm total, I'm losing coupling, close focus is about 22" but far distance is down to about 3.5 ft. Going back to 2 shims where coupling remains, and I only lose ~2 inches, and gain many inches in far focus/total focus.

 

[Pherdinand]

You get disproportionally further from the film plane when you get closer to your subject.
Eventually, for REALLY close subjects, you will have to put the camera body to infinity.

Do you have enough credit cards for that ? 😀

 

[ampguy]

haha

haha

You know, when you cover the 6 bit sensor area with the magnetic part of a cut up card, the shutter sound changes to "ka ching" !! 😀

You get disproportionally further from the film plane when you get closer to your subject.
Eventually, for REALLY close subjects, you will have to put the camera body to infinity.

Do you have enough credit cards for that ? 😀

 

[P. Lynn Miller]

Interesting that the M8 will couple well past 0.7m...

 

[ampguy]

Yes, I was surprised

Yes, I was surprised

That setup was great for taking a walk and shooting flowers at distances I'd normally use an SLR or macro setup for, but ultimately the lack of focusing past a few feet got me to undo that setup for a more in-between rig with the J3.

Interesting that the M8 will couple well past 0.7m...