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  1. #1
    Sparky's Avatar
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    SHEER frustration... anybody know any focusing tricks...???

    Hey all...
    So - I've been printing on my devere 504 for the last year or so... to make a long story short I can't use the focus knobs because it's set up for murals... that being said - I have to unlock the neg or light source track and then guide it gently up and down from the position it needs to be in for best focus, and then lock it down again. At any rate- when I'm doing bigger prints - it requires a lot of back and forth between the floor with my focuser and the head. This can be a multi-hour affair - JUST TO GET THE FOCUS. The pay off is totally worth it - ultra crisp grain, etc... but getting there is a BIG pain in the pitootie...!! Has anyone dealt with this kind of thing before?? Maybe Bob Carnie....?? Others?? I'm at the 1.5 hr. mark right now - and short of rigging up a special mechanical assembly... I was hoping one could set up some sort of trick, using mirrors - or god knows what to achieve rapid, accurate focus...

    any takers??

  2. #2

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    Hi Sparky, is this a wall mounted, bench, or floor standing enlarger.

    When you say you cannot use the focussing knobs, do they have no effect whatsoever. If so, it sounds as if the control cables in the column have either broken, lost tension, or been partially disconnected. As the locking knobs are working, the control cables from each to the head/lens stages are OK (so probably not broken).

    If it is a floor standing enlarger, the drive chains in the pedestal may have been disconnected.

    There is a service panel on the back of the column which you can remove to check the state of the drive cables, and if it is floor standing, there are two service panels on each leg of the pedestal, which can be removed to check the state of the drive chains.

    For the drive cables, there is a retaining block on each onto which the two ends of the drive cable are attached. The lower section of the cable goes into an adjuster bolt, so if the tension has been lost, and there is not enough friction for the drive pulleys to drive the cables, undo the lock nuts on the bolt, and tighten the cables with the adjuster bolt.

    For the locking knobs to work, the upper section of the cable will be OK, but the lower section may be broken, or disconnected. If it has been disconnected, it will probably still be attached to the adjusting bolt, so will be easy enough to reattach. If it is broken, then spares can be obtained from Odyssey Sales in the UK, they have a contact form so hopefully would be able to refer you to a local distributor.

    If it is floor standing, removing the top panel on each of the legs allows you to check the tension in the drive chain. If it is a floor standing enlarger, let me know and I will sort out the details for adjusting the chain tension. I seriously doubt these would ever break, even if the drop bed had been used as a jack for a car!
    Steve

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  3. #3
    sun of sand's Avatar
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    I have no idea what the situation is but I can focus well without a grain magnifier
    I rack to focus and then beyond focus and then do it once again counting in my head the time it takes from out of focus to out of focus
    Split that time or distance and you're pretty good.

    why wont this work?

  4. #4

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    Quote Originally Posted by Sparky View Post
    ... some sort of trick, .... god knows what to achieve rapid,
    accurate focus... any takers??
    I know! I call it Focus Once. May be of some help. Next time
    you go through the chore of focusing make note of the head
    height AND A exact dimension of the projected image.

    No need to focus other than to that exact dimension for same
    repeats. I add a new column mark now and then as I change
    negative size and have a short table of projected sizes. Dan

  5. #5
    ic-racer's Avatar
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    **Motor focusing. Though probably not an option for the 504.
    **WA enlarging lens.
    **There used to be a 'long' grain focuser, perhaps 2 feet long, don't recall the vendor. (This would be a 'trick' using a mirror )
    Last edited by ic-racer; 10-06-2008 at 06:31 PM. Click to view previous post history.

  6. #6
    Maris's Avatar
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    When the enlarger head is too high and no amount of "ape hanger" position will reach the focus knob I get a friend in. One person watches through the focussing magnifier and calls "up", "down", "ok" while the other tweaks the focus knob.

    Doing mural size enlargements is usually a two person job (in my darkroom at least) so the "focussing assistant" job already has a volunteer.
    Photography, the word itself, invented and defined by its author Sir John.F.W.Herschel, 14 March 1839 at the Royal Society, Somerset House, London. Quote "...Photography or the application of the Chemical rays of light to the purpose of pictorial representation,..". unquote.

  7. #7

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    I recall reading a suggestion to use a small telescope to aid in focusing mural-sized enlargements. I've never tried this myself, though; I'm just passing on something I recall reading (I believe in another thread here on APUG).

  8. #8
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    Having done mural enlargements with horizontal 10x10" DeVere enlargers on rails, I can verify that getting quite reasonably correct focus is not that easy.

    What we used to do was don a pair opera glasses that had been fitted to a pair of spectacles without any glass. These are usually between 2x or 3x magnification only, plus they are quite light gathering and allow you to see grain remarkably well. These units are quite good for getting very close focus.

    Then we used to stand up at the wall with a Peak grain focuser with the remote unit in our hand. You would be surprised at how difficult it is to get dead accurate grain focus with a motorised set-up. The motor always has a slight over run, basically you end up guestimating and it usually takes about 5 minutes at the minimum to get correct focus, especially after you stop down and check the grain over the entire 6' high by 18' wide paper area.

    Reading your description it appears that you are using a free standing DeVere with the table dropped to the floor but no standard forward controls fitted. Either that or you are using a table top model wall mounted and no forward controls.

    We had one vertical 507 DeVere that we did enlargements onto 24x30" paper. That enlarger was bog standard and when the drop table was on the floor, with the head almost touching the ceiling, you needed an assistant to focus correctly.

    The reason was that you would be on your hands and knees and the lock controls are halfway up the wall, not being an Ape with extended arms, we used Maris's technique of lock, unlock, lock again, etcetera.

    I don't think there is an easy solution to getting super critical focusing single handed.

    Mick.

  9. #9

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    Can you focus by just looking a projected image, and when get reasonable sharpness, stop lens for small aperture, f11 or f16 or f22?

    It seems to me it would be only way without help of another person or some tool.

    Next, some enlargers have focusing aids in their heads. For example Meoptas enlargers have hairline focusing aid, that is when you pull negative carrier slightly out of head, you project two shorter white lines on image plan, and when those lines are combined into one longer line and that line is sharp and thin looking on image plane, enlarger is focused.

    Do your enlarger have something like that, or can you put something into negative carrier which will simulate hairline focusing aid? You can find images of Meopta enargers negative carriers, and make something simillar for your enlarger.

    And you allways can ask someone as for Maris's procedure.
    Bosnia... You don't have to be crazy to live here, but it helps...
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  10. #10

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    The DeVere has the advantage of a remote control. For the rest of us, you can usually rig something. There are long flexible shafts you can buy that fit in place of the focusing knobs and will give you two to four feet of extension. The problem with these is backlash - turning the knob at the end of the shaft does not always result in a corresponding smooth change in focus; rather, the changes may be jumpy and difficult. If you are electronically inclined, you might be able to rig up a big stepping motor and a remote switch. A small telescope or optical gunsight is a possibility, although poor illumination through one of these may be a factor.

    Another problem with focusing for murals is poor illumination. The easel may just be too dim. I don't know of a solution for this, except maybe a bigger enlarging lamp. With good lenses, you can open up to get more illumination. But with many lenses, the focus will change noticeably between wide open and a couple of stops down. Fortunately, exact focus is less critical for murals. You are at a degree of enlargement where the resolution of the taking lens and the film limit the sharpness. Poor enlarger focusing will make that situation worse, but getting fairly close will work.

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