Durst 138 to 8x10?

Discussion in 'Darkroom Equipment' started by Doc W, Oct 29, 2018.

  1. Doc W

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    Is it possible to convert a Durst 138s (5x7) enlarger to an 8x10 enlarger? Has anyone done it?
     
  2. ic-racer

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    Member jp80874 has or had one.
     
  3. Lachlan Young

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    It's perfectly possible (& quite a few have done it), but you'll need to machine out the chassis, make a new neg carrier, possibly new bellows, and get a suitable head that covers 8x10. Really a question of trade-offs between skill, time, money & costs of getting a native 8x10 enlarger.
     
  4. DREW WILEY

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    It's fairly easy to do if you don't need to make prints bigger than 20x24 when the enlarger is vertically oriented, although the 138 quickly repositions for horizontal projection too. You also have to consider ceiling height. My own conversion utilizes a 12X12 inch V54 cold light, which is relatively flat, so works in a room with an ordinary 8 ft ceiling, whereas my true 8x10 enlargers equipped with halogen colorheads are set up in a different room with a higher ceiling.
     
  5. Kshaub103

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    Yes jp has one I got to see it a while back, Michael Mutmansky did the conversation on the durst. Very nice machine. I’m working on a conversation of my durst 138 as well.
     

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    Doc W

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    Thanks for the replies and the photographs. I am pretty stoked about doing this. How would I get in touch with Mr. Mutmansky?
     
  7. ic-racer

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    There really isn't anything in the box. It just has an 8x10 negative holder under the light source and a means to attach the box to the enlarger below and the light source above. I'd source an 8x10 negative holder and a light source and build the box around those two key components.

    Screen Shot 2018-11-04 at 10.11.37 AM.png
     
    Last edited: Nov 4, 2018
  8. OP
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    Doc W

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    Thanks, Lachlan. I don't understand "machine out the chassis." Where must this be done and why?
     
  9. OP
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    Doc W

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    ic-racer, that is the Heiland unit which sells for close to 3K. It looks great but it is out of my league!
     
  10. ic-racer

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    Single color LED panels can be inexpensive. In that case you can use 12x12" filters and would need to make a separate filter holder slot between the LED panel and the negative stage. Or make an under the lens holder for 6x6" filters.
    finished1-1.jpg
     
    Last edited: Nov 5, 2018
  11. Lachlan Young

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    It can be done if you want to keep the height about the same as it is without modification - I think it grew from the realisation that the normal neg carrier is about 8x10 in size (excluding the 'ears') & still has plenty of bearing space on the chassis at the neg stage. The focus drive system is also plenty long to handle a 300mm lens. Essentially what you do is machine out an 8x10 hole in the neg stage (I think that you'll need to sacrifice the masking bars too) - which will still leave plenty of structural strength in the chassis (big casting essentially). Major consequence however is that you need bigger bellows immediately at the neg stage, so those need fabricated, as does a neg carrier & a suitable source of illumination. It's definitely not reversible, unlike some of the other approaches which are closer to the Alan Ross/ Beseler 8x10 conversion in setup & add significant height to an already big machine.

    EDIT: here's a picture of what Glenn Evans ends up with after machining out a 138 to 8x10
     
    Last edited: Nov 5, 2018
  12. Kshaub103

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    I was told he stopped doing the conversions but there as a similar conversion talked about briefly here, https://www.photrio.com/forum/threa...-durst-l184-and-beseler-cb7-parts.30441/print unfortunately it look like the website was updated and when i contacted Jeromie he didn't save any archive of the conversion, he called it the DurstZilla tho. i hope to one day to finish this project, i just haven't came of with a solid plan.
     
  13. OP
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    Doc W

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    Thanks, Lachlan. So it looks like I would have to do some machining if I want the machine to be the same height. I don't mind it being taller, however, and I already have a hole cut in the ceiling to accommodate the column. I am going to pursue this but I am not in a great hurry. It looks complicated!
     
  14. ic-racer

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    Not sure about the comments about height, but the 8x10 diffusion head conversion of jp80874 is the same height as the 5x7 diffusion head. The bellows are not changed. The difference is that the 5x7 head is a color head and needs a color mixing box with the negative below. That box is about the same size as the hollow bellows-extension box on jp80874's 8x10 conversion. As you can see the placement of the negative is different in each.
    Screen Shot 2018-11-06 at 11.07.35 PM.png
     
  15. ic-racer

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    Using a 5x7 CLS301 mixing box for the conversion might save some construction. The bottom of the CLS301 head is about 8x10 because it is the same for both 8x10 and 5x7 versions; just the mixing box is different. Of course you can't use the CLS301 head, because, in itself, it does not provide even light. A LED panel, or Aristo head would be needed to fit on top of the modified CLS301 5x7 mixing box.
    Screen Shot 2018-11-06 at 11.21.20 PM.png
     
  16. DREW WILEY

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    No need for a mixing box if you use a big enough cold light. My 8x10 conversion for the L138 uses a 12X12 high-output Aristo blue-green V54. The high-output version is basically overkill; but I sometimes register unsharp masks onto the original neg, equating to more overall density. Therefore this was a deluxe option for me, and I love the thing. But I really don't know what's still made in terms of cold lights. Cheap LED lighting panels are far too weak for serious enlarging use.
     
  17. btaylor

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    High output high CRI LED lighting panels are out there, they light movie sets with them.
     
  18. DREW WILEY

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    Nice to know, since big cold lights are getting harder to find.
     
  19. Lachlan Young

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    The serious LED's are quite scary in terms of how good their accuracy is - they've been used quite heavily in the last few years on quite a few films originated on S16/35/65mm etc especially as practicals etc. The ones often used for practicals can be bought as strips/ rolls (at a price) & are probably worth investigating further. Or if you're mad enough, see if you can find LEDs that match the peak transmission of #70, #98, #99 filters...
     
  20. OP
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    Drew, I would love to hear more details of the conversion and see some photos as well.
     
  21. DREW WILEY

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    I don't own any kind of digital camera. But the adapter is basically just a well-fabricated rectangular box just about the size of the cold light itself (12X12 inches), about 8 inches tall overall, with a white plexiglass diffuser about an inch above the neg carrier tray, which has two sheet of optical glass. Since the V54 has plenty of output, I use an Apo Nikkor 305 graphics art lens (late 4-element style), which is smaller than ordinary enlarging lenses that focal length, but with a max aperture of f/9.
    It's way better corrected than any typical enlarging lens, and easily fits into the Durst lens turret with an appropriate adapter (which I had custom machined). It was a fairly easy project overall. But this particular 138 chassis was bought for parts; and once I completed refurbising another 138, I thought of what to do with this one, and in route needed to replace the old baseboard, which was warped. Easy enough. And I added the Zone VI equivalent of a light integrator, which times (beeps) based upon a probe and actual light intensity rather than seconds. Works great.
     
  22. ic-racer

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    LED technology is advancing rapidly. Drew knows I have the massive CLS 2000 head and I have been stockpiling EST 2000 power supplies, Coolamp 2000 halogen lamps and dichroic reflectors. Over the last ten years I now think all the posts I made on LF forum po-po-ing LED in favor of halogen/dichroic are now outdated and probably wrong.
     
  23. DREW WILEY

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    I'm not poo-pooing LED at all - I'm pooping on it! Yes the technology is advancing rapidly. But that is a significant aspect of the risk itself. Just like digital equipment, things are moving so rapidly that once you need to repair something or replace a component, it might already be obsolete. Or the company that made the device might be out of business because someone else came up with a more effective tweak at significantly lower price. By contrast, most halogen enlargers use bulbs that
    have been standardized for decades. You still need to be fussy about mfg quality, but otherwise, a modest reserve of bulbs could sustain you a lifetime. The next issue is sheer luminance output. How do you squeeze enough in a surface only a foot across at best (for 8x10) to have significant punch. The third problem, a really big one, is that LED's aren't quite there yet in terms of color printing applications. You either need quite precise RGB peaks, each of them powerful, and a way to variably control them without luminance unpredictability or loss, or else a true continuous spectrum that can be tightly trimmed at the necessary points by dichroic CMY filters. But in terms of VC black and white papers, that's a much easier problem to solve, and LED's might indeed logically replace cold light tubes. Whether they run just as cool all packed in together without affecting one another's tiny wiring is another problem, but I can think of much worse headaches I've had to deal with in colorhead design.
     
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