How do adjust Minolta Autocord focus?

[DLM]

After having run about 15-20 rolls through my Autocord, I've started to notice that on shots taken at a larger aperture, where dof is narrower, I seem to miss the focus. I processed 5 rolls from a recent family trip, and it was frustrating to notice that a few were out of focus when I know for sure that the WLF was showing it in focus. My question is, what is the easiest way to remedy this? When I take the WLF off, I don't see any way to adjust the mirror or gg. Do I have to adjust the taking lens?

 

[SWphoto]

I'd contact Karl Bryan in Oregon, who does great work on Autocords and adjusted the focus on mine perfectly. You can reach him at karl.kathy@verizon.net. He uses equipment I don't have.... If you are looking to do it yourself, perhaps another forum member can help.

 

[Andrew K]

on any TLR the adjustment is pretty much the same

-set the focus to infinity (wind the focus rack right in)

- open the back and check the focus at infinity on the taking (lower lens) using ground glass in the film plane

- if it is out of focus at infinity you will need to adjust infinity focus - usually by removing the cover from the centre of the focussing knob, and losening and adjusting the locking screw until you acheive infinity focus at the infinity stop (that is with the knob wound back to infinity)

- now you adjust the viewing lens to infinity - you can do this either by rotating the front of the lens on some cameras to reach infinity, or adjusting the mirror angle to reach inifinity

on a Autocord the adjustment is slightly different if you have the focussing lever on the bottom of the lens panel - you need to rotate both lenses to acheive infinity focus

you now have a camera that should be focussing correctly

 

[matreve]

you need to rotate both lenses to acheive infinity focus

you now have a camera that should be focussing correctly

Unfortunately, this is not correct. Only the viewing lens rotates as a unit (and is locked by a set screw not accessible without partial disassembly). On the taking lens it is just the lens block/cell in front of the iris and shutter that can be easily rotated/unscrewed but that obviously does not work as this alters spacing between elements (Rokkor is a Tessar type lens which on most cameras is unit focusing, not front cell focusing). Adjustment of the taking lens's infinity is done by removing (or adding) washers/lens shims and adjusting entire lens's position, not just front cell.

 

[Dan Daniel]

Three issues in a TLR. 1, is the taking lens properly adjusted for infinity? 2, does the viewing lens show the same focus as the taking lens? 3, are the taking lens and viewing lens tracking?

1- proper testing equipment needed. For the Autocord, the adjustment will be shimming the shutter block in or out. Probably not on the OP's plate.

3- If the two lenses aren't the same focal length, you can get the two lenses to match at any point in the travel, and as you move to other focus points, they will drift further and further away. Not much you can do about this without access to multiple lenses and test equipment. By same focal length, this means to the 1/10 or less mm, not just markings on a lens barrel. For example, Rollei lenses are usually pencil marked to 1/100mm.

All in all, just trust the factory on this!

2- this is where the fun starts. There is a set screw for the viewing lens under the lens shroud. This is the factory adjustment and the best way to get the viewing lens to match the taking lens. Have ground glass in film plane. Adjust viewing lens in and out to get its focus screen focus to match the taking lens ground glass focus.

Another approach is to shim the focus screen in or out to get focus to match the film plane. Remove focus hood, try shims under the side edges of the hood. If it gets worse, remove screen and add shims on the top side edges of the screen. Basically moving the screen up or down in space. Slower than the direct adjustment of the viewing lens. Scotch tape (the very thin stuff for paper, not painter's masking!) is a decent shim material, about 1/10mm in thickness.

If you do remove the lens shroud, it's pretty simple. Remove skin (older ones will need chipping away) to expose five screws holding in place. Note that screw at bottom is smaller than other screws. If there is an M/X slider at the bottom of the lens, you'll need to unscrew the little knob- standard threading. The shutter and aperture tabs are incorporated into the shroud so no removal.

You can do this adjustment of focus at most any distance, by the way. Meaning get film plane focus and screen focus to match. So you can use a cereal box in a living room, or a sophisticated infinty collimator. The importance is matching. If you are shooting portraits, for example, test at close distances.

 

[IOWA CAMERA GUY]

After having run about 15-20 rolls through my Autocord, I've started to notice that on shots taken at a larger aperture, where dof is narrower, I seem to miss the focus. I processed 5 rolls from a recent family trip, and it was frustrating to notice that a few were out of focus when I know for sure that the WLF was showing it in focus. My question is, what is the easiest way to remedy this? When I take the WLF off, I don't see any way to adjust the mirror or gg. Do I have to adjust the taking lens?

You may have one of 2 problems going on here:

The focusing mechanism may be out of adjustment - that's possible, but unlikely. The camera's focus is adjusted at the factory, and unless the camera was dropped and things got 'out of alignment', they are probably OK.

By out of adjustment, I mean that the actual focal plane of th lens and the focusing screen may not coincide, but that is, as I noted, unlikely.

More likely is that with the reduced depth of field you probably just missed the exact focus-point adjustment when you focused.

With a larger aperture, the shutter speed can be/is higher so camera movement is also a chance, but small(er).

Perhaps you are mistaking blur from camera movement (does not take much) with missed focus.

Apparently, this has not been an issue with the "15-20 rolls" you have shot, so I'd vote for camera movement.

65+ years taking photos, owned a camera store - my 'credentials'.

 

[Dan Daniel]

More likely is that with the reduced depth of field you probably just missed the exact focus-point adjustment when you focused.

Yep! One thing with TLRs is that the camera is much more 'free floating' than with camera directly at the eye. You move the camera to put your subject at the center and focus. And then you need to reframe for the actual shot. Much easier with a TLR to move the whole body around, sway back and forth in the process of reframing. And hence lose focus if depth of field is shallow.