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djon43
Joined: 16 Oct 2005 Posts: 18 Location: Albuquerque NM
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Posted: Sat Jan 21, 2006 1:56 pm Post subject: |
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OK, I've talked about this, now I'm about to do it..
I will try to adjust my Century Kalart to work with my 135 Xenar...a major change from the current perfect 80mm focus adjustment, which I hate to risk.
I have Graflex.org instructions AND a photocopy (free from Camera Eccentric).
I only have one question..where do I start?
Presumably (?) I begin with the rails at total back position (same as "infinity" for my current 80) and then simply (!) slide the front standard with 135 forward and backward until I find its infinity point...yes? no?
OK, after that, do I also have to adjust the infinity screw as well? Can't I just leave that one alone? Is it mostlyfor fine infinity focus after 15/4 adjustments?
I expect to be able to do the 15' and 4' adjustments OK, but that first Infinity step seems like a big one!
That's what they've always said about Infinity, of course.
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Dan Fromm
Joined: 14 May 2001 Posts: 2146 Location: New Jersey
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Posted: Sat Jan 21, 2006 4:23 pm Post subject: |
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On 2006-01-21 05:56, djon43 wrote:
OK, I've talked about this, now I'm about to do it..
I will try to adjust my Century Kalart to work with my 135 Xenar...a major change from the current perfect 80mm focus adjustment, which I hate to risk.
I have Graflex.org instructions AND a photocopy (free from Camera Eccentric).
I only have one question..where do I start?
Presumably (?) I begin with the rails at total back position (same as "infinity" for my current 80) and then simply (!) slide the front standard with 135 forward and backward until I find its infinity point...yes? no?
OK, after that, do I also have to adjust the infinity screw as well? Can't I just leave that one alone? Is it mostlyfor fine infinity focus after 15/4 adjustments?
I expect to be able to do the 15' and 4' adjustments OK, but that first Infinity step seems like a big one!
That's what they've always said about Infinity, of course.
| Well, unless the Kalart thinks it is at infinity when the lens is at infinity there's not much sense proceeding. Find the lens' infinity position, set the stops to put it a hair behind that position, focus it to infinity on the GG, set the Kalart's infinity aduster so that it too thinks the lens is at infinity, and then go on to adjust it for closer distances. |
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djon
Joined: 05 Nov 2004 Posts: 174 Location: New Mexico
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Posted: Sat Jan 21, 2006 4:42 pm Post subject: |
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This seems contradictory, or redundant:
"Find the lens' infinity position, set the stops to put it a hair behind that position, focus it to infinity on the GG"
Doesn't "find" require focusing at infinity in the first place?
I'd guessed earlier that this meant sliding the standard fore and aft until I got focus, then setting the stops...this seems to conflict or overlap with the infinity adjusters's job.
If I'm finding infinity visually, what's the role of the infinity adjustor? I was guessing that this would be for fine tuning, later in the process...? |
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djon
Joined: 05 Nov 2004 Posts: 174 Location: New Mexico
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Posted: Sat Jan 21, 2006 4:44 pm Post subject: |
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...wait..a-ha!...maybe you're saying that I set the lens's infinity position on the rails and that the screw SEPARATELY adjusts the Kalart...is that it?
Gotta adjust the lens/standard all by itself, and then the Kalart?
Is that right?
[ This Message was edited by: djon on 2006-01-21 08:47 ] |
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djon
Joined: 05 Nov 2004 Posts: 174 Location: New Mexico
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Posted: Sat Jan 21, 2006 5:35 pm Post subject: |
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What sort of setback from perfect full aperture focus at infinity would you expect, assuming shots were generally at f16 (rule of thumb?)?
Like 1mm or...?
I'll test this, but I'd like a cross reference...
As well, if there's a little focus-patch lateral non-alignment, is that something you'd fool with, assuming it's not an irritant? Or is that as easy/difficult as the rest of this to adjust?
[ This Message was edited by: djon on 2006-01-21 10:08 ] |
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djon
Joined: 05 Nov 2004 Posts: 174 Location: New Mexico
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Posted: Sat Jan 21, 2006 8:22 pm Post subject: |
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OK, all done
"iterative" is an understatement. The biggest interation hassles were the final infinity adjustments: critical to about 1mm of rotation with the 135.
This was fun. I'm sure I did a good job. The only question now is if I'm happy with using 135mm for portraits at 4'..head and shoulders stuff...will I get enough depth of field etc...I guess I can always back off, if not. I'll test today.
The 80mm Heligon that I began with was evidently at one extreme of Kalart's lens range... 135 may be the other extreme. But everything looks poifect, including the lateral which was easier with my particular Kalart, a "modern" Century, than the various instructions indicated...just one screw to adjust.
Graflex! Dang, whatever happened to funky, manly, American machines like this? Whenever Graflex had the opportunity to change screw sizes, they leaped at the opportunity.
Tools: solid tripod, tape measure, focus loupe, set of decent small screwdrivers ("Omega" from Home Depot is ok), crappy eyeglass repair screwdriver for fine screws on the short range (front) adjustor.
EXCELLENT Kalart adjustment instructions... originals, good photos, free: http://www.cameraeccentric.com/html/info.html
[ This Message was edited by: djon on 2006-01-21 12:26 ] |
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troublemaker
Joined: 24 Nov 2003 Posts: 715 Location: So Cal
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Posted: Sun Jan 22, 2006 4:36 am Post subject: |
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[ This Message was edited by: troublemaker on 2006-01-26 17:29 ] |
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djon
Joined: 05 Nov 2004 Posts: 174 Location: New Mexico
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Posted: Sun Jan 22, 2006 4:05 pm Post subject: |
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8:44-12:22...that was the time I invested in the process, working steadily but leisurely and with a coffee break.
Trouble, thanks for your detailed response...and I'd welcome more of your insights because I want at least to confirm the current state of affairs...
I'm confident (always a bad sign), but I'll shoot film today at close distances to confirm...the last cycle of iterations was, um, loooong, but I buckled down and did them. I do have perfect infinity (distant mountain ridge) and perfect 4' and 15', at least according to ground glass/fresnel. I'll note here that with fresnel a low magnification loupe is much better than, for example, 8X (I use a 105mm enlarging lens...perfect with the hood). I imagine it'd be better to do all of this without fresnel, just ground glass, and with higher-powered loupe for this reason, |
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troublemaker
Joined: 24 Nov 2003 Posts: 715 Location: So Cal
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Posted: Sun Jan 22, 2006 6:52 pm Post subject: |
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[ This Message was edited by: troublemaker on 2006-01-26 17:30 ] |
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djon
Joined: 05 Nov 2004 Posts: 174 Location: New Mexico
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Posted: Sun Jan 22, 2006 7:17 pm Post subject: |
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...it was a good reminder to keep the original focus stops in place (to more easily readdjust for the original if desired, and just for its infinity in any case ... I'd installed a second set of stops on my rails, which probably makes me a rich man in the world of Graflex-shooters...and I will install a third, for my Tele Optar, when I get more.
The main question I have now is whether I'll need to refocus again, with no fresnel, to do a finer job to compensate for f16 (for example) Vs the full aperture with which I've been adjusting. |
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djon
Joined: 05 Nov 2004 Posts: 174 Location: New Mexico
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Posted: Sun Jan 22, 2006 9:22 pm Post subject: |
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Trouble, thanks for the detailed posting...valuable stuff in a time of vanishing mechanical aptitudes, ambitions, and courage!
How in the world can we do this stuff without buying digital calibration devices?
This process has been BIG fun for me. |
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troublemaker
Joined: 24 Nov 2003 Posts: 715 Location: So Cal
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Posted: Mon Jan 23, 2006 6:42 am Post subject: |
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[ This Message was edited by: troublemaker on 2006-01-26 17:31 ] |
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djon
Joined: 05 Nov 2004 Posts: 174 Location: New Mexico
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Posted: Mon Jan 23, 2006 11:33 pm Post subject: |
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My grandfather was a shade tree mechanic, obsessive about getting gizmos to work right and building things properly.
His dear wife, my grandmother, regularly had to restrain his swearing and raging when he couldn't make them perfect immediately..and especially had to quell his blue language when their little grandson was visiting...
I guess tinkering with things like this is "viral."
[ This Message was edited by: djon on 2006-01-23 15:34 ] |
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troublemaker
Joined: 24 Nov 2003 Posts: 715 Location: So Cal
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Posted: Wed Jan 25, 2006 8:16 am Post subject: |
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[ This Message was edited by: troublemaker on 2006-01-26 17:30 ] |
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