close ups with the Canon 28/2.8 ltm

ampguy

ampguy

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I decided to take the 2 shims which allow my 50/1.5 J3 to focus to .7m off, and put them on my 28/2.8 ltm lens.

I wasn't expecting much, as Brian had mentioned the shimming in this method was really only for 50mm lenses.

Well that's partially right, but what I didn't realize is how close that ~1mm of shims would let me get, which is about 12" or closer than any M or LTM lens I've used.

The odd thing, is it doesn't lose coupling, so if you try to use the RF, you'll be way too far out. It's definitely for digital use only, probably the most ideal would be a live view 4/3 or NEX type, although the M8 gives enough feedback, so within a wasted frame or two, you're in the zone.

Pretty interesting, wish the coupling matched the close focus, but I'll have to remember this trick when I get an EVIL type camera for this lens.

I might try a single shim (.5-.7mm) but would expect it to not be able to get as close as 12", but to possibly stay coupled closer to however close it ends up focusing at.

photos later, when I pull the card out.
 
well, a single shim still lets me focus almost as close as 2, but the coupling is still off, but not as bad as with 2 shims. At closes focus, still about 12", you need to focus about 8" behind the subject. Far focus is way out there though, maybe 30 feet +.
 
I've found a pretty reliable method for close focusing at it's min. of about 12"

In the RF, when one image of the cat's ear base is just along side the 2nd superimposed image of same ear, that's sharp focus.

Otherwise, it's back focusing about 8 or 10"

I think I'll save these shims for when use on an EVIL type camera, and move them back to the J3 where it couples. 1m is good with RF's anyways.
 
I have thought about doing this with a cv 15mm/4.5 for taking shots of architectural scale models. If you can place the camera up close or into the model you can get nice wide angle shots from realistic viewing positions. Something like a nex (which I don't have) would be ideal for that.
 
Here's an uncropped image from the M8 with Canon 28/2.8 with both shims in, I'd guess ~10 inches or so, have never focused closer with an RF:

1007134801_zfrnU-L.jpg
 
You could make a secondary scale for the lens used with the shims- kind of like what a Kodak Retina IIIc does for using the 35/4 and 35/2.8 elements. With that camera, focus using the RF as you normally do, get the scale reading and refocus the lens using a secondary scale. With the 28 used close up, while the RF coupling holds, make a table of known distance vs what the RF indicates. Ie: set the focus correctly, confirm it using pixel peeping, then without moving the camera use the RF to get the distance. That becomes your look-up table. Then you can focus using the RF, use the table, and refocus the lens.

This should work, but i have not had coffee yet...
 
Hi Brian

Hi Brian

I was thinking of that, do you know of an adhesive white tape that I could mark, that leaves no residue when taken off?

The other thing I may try is an even thinner shim, like envelope paper that lets me get to say 24" and stays focus coupled. I am not sure how often I'd use the lens that close, generally when I want that FOV, I put on a 50 or 75 (or 105/2.5 with slr or dslr), but the main advantage would be to a) hopefully keep the rf/vf coupled to ~24" and in a pinch, stopping down and getting out there really far to stay a general purpose lens.

Brian Sweeney said:
You could make a secondary scale for the lens used with the shims- kind of like what a Kodak Retina IIIc does for using the 35/4 and 35/2.8 elements. With that camera, focus using the RF as you normally do, get the scale reading and refocus the lens using a secondary scale. With the 28 used close up, while the RF coupling holds, make a table of known distance vs what the RF indicates. Ie: set the focus correctly, confirm it using pixel peeping, then without moving the camera use the RF to get the distance. That becomes your look-up table. Then you can focus using the RF, use the table, and refocus the lens.

This should work, but i have not had coffee yet...
Click to expand...
 
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OK - here's an update with a very thin shim, made out of an old NWA worldperks card, this would be thicker than standard paper by maybe 2x, but about 1/2 to 1/3rd the thickness of a 1mm credit card.

Close focus is 24", and coupling works, but is off a bit (only at min. focus), back focusing about 6" at 24"

However, in a pinch, can be used for very far distances, stop it down to f8, and infinity is sharp enough.

Not sure I'm going to stay with this setup, there is one odd ergonomic quirk, the focusing tab is now on the upper part of the lens, making it awkward to focus, but the 12" gain in closeness is pretty impressive, and could save a lot of 28 to 50 lens swaps.

Next test - put the worldperks shim on the J3, see if I can get infinity, and maybe as close as .8m.
 
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Well I think my final test with shims and the Canon 28/2.8 will be to use just a piece of aluminum foil, hard to think of anything besides paper that is really thinner than that worldperks card.

If the foil allows for coupling, even if at .9m, and infinity, that could be interesting.
 
well I took all the shims out of the Canon, so it's back to full infinity, and 1m close up.

I did put the paper thin plastic spacer (out of the old NWA card) onto the J3, and it gives me about 11 more cm (32") which is noticeable, but as expected is the tiniest amount off at infinity. I'll probably keep it like this for a week or so and see how many infinity shots I'm missing after peeping to 200% or so.

Everything is done wide open, I think the hood has even locked the aperture dial into fixed wide open, a tad more than the 1.5, but last time I measured it against the pre-asph lux 43, it was a good 1/3rd stop slower than 1.4 on the lux, maybe coatings.

Perhaps shooting at max infinity with the shim will equal out the aberrations from wide open shooting and result in a better image anyways 😉
 
This is work if you are using digital, but with film it would be abit of a struggle to get in-focus negatives.

But with the homework done and a secondary scale as Brian mentions, I could see this working for a wide or super-wide angle lens.
 
yes, would not be usable with film

yes, would not be usable with film

With the M8, once in the range, I was getting about 1 in 3 in focus.

I decided to hold off on the scale, and super close focus of this because even with a scale, it's kind of weird to be having a ruler or tape measure, or even bulkier my laser/sonar sensor going.

I do plan to put the shims back on when I get an EVIL type camera, NEX, u4/3 or ??? - then I should get great close ups and every one in focus, if I can see the screen ...

P. Lynn Miller said:
This is work if you are using digital, but with film it would be abit of a struggle to get in-focus negatives.

But with the homework done and a secondary scale as Brian mentions, I could see this working for a wide or super-wide angle lens.
Click to expand...
 
Actually scale focusing with a tape measure can be a handy when using a wide angle...

2008_08_016_016_700e.jpg


I put the Bessa R2 with the Ultron 28/2 on a small table-top tripod about 3 inches off the pavement and set it up 0.7m from the blade using a tape measure. Would have been impossible or nearly so to focus using the viewfinder. And this was shot at f2.0, so not alot of room for error.
 
get a caliper reader

get a caliper reader

finally broke down and went to harbor freight and plucked down 9.99 for a $29.99 caliper that is supposed to be accurate to .0001"

If anyone needs to know any thickness of shims, I can now give accurate readings!

ampguy said:
Here's an uncropped image from the M8 with Canon 28/2.8 with both shims in, I'd guess ~10 inches or so, have never focused closer with an RF:

1007134801_zfrnU-L.jpg
Click to expand...
 
Ted, is the caliper Digital readout, or all "analog" scale?

I have some of the latter, use a digital caliper. They used to be "not cheap".

the thinnest shims that are normally encountered are 0.02mm. These are on the CZJ Sonnars. They usually do the trick, able to get well within the DOF for F1.5.
 
Hi Brian,

It is digital, I think with 3 or 4 spaces after the dot. HF did have all analog dials, but I didn't see that I would be able to read more than about .01 accuracy on them. They also had hybrids.

What interests me is using standard RF lenses on a NEX or EVIL type camera for close ups indoors (flowers, plants, pets), then taking the shim off for infinity capability outdoors and for general use. So this just involves a shim or shims to extend the LTM lens out further from the lens flange, allowing wides extreme close up, at the expense of far focus, now just a matter of feet.
 
Some measurements for getting ~10" to 5ft focus with the Canon 28/2.8 LTM lens:

CV Type 1 LTM adapter: 0.999 mm

Credit card shim: 0.737 mm

thin expired NWA WorldPerks card: 0.254 mm

Total thickness to get from ~1m close focus to ~ 0.25m : 1.99 mm

More close ups will come when pull the card out.
 
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