Repairing a Dejur 4x5 enlarger

[jnovek]

First: me. Long time APUG lurker, but I don't think I've ever posted anything. I have ~2 years of darkroom experience and I've done all the typical maint. on my 35mm condenser enlarger -- cleaning, alignment, etc. but this is my first time repairing a less-than-pristine piece of gear.

I'm working on an old Dejur 4x5 diffuser enlarger that (!!!) someone threw away. I'm mostly ready to go, but I need to tack down a few things... any thoughts?

1) The diffuser is gone. I presume that this enlarger had a ground glass or opal glass plate at one time. I am going to need to buy or build a replacement. Where should this sit? Over my fine, hand crafted negative carrier, or close to the light source?

2) What bulb should I use for this enlarger?

3) While I can control the left-right axis of the enlarger head (and the front standard swing for some reason) for alignment purposes, I can't control the front-back alignment. Of course, the head is out of alignment with the baseboard on the front-back axis.

I've noticed that the head does not stay firmly in place on the back post, and leans a little bit forward. There seems to be a little bit of space in the collar that slides up and don't the post... this causes the head to be at a slight angle with the post and if I lift the head up so it isn't at an angle, it is at least level (I can't comment about alignment).

I've considered wedging something between this collar and the post, but this would be inconvenient as I would have to replace it every time I moved the head up or down.

I've also considered just shimming the post where it meets the base to get it into alignment. Would this hurt the stability of this already slightly shaky enlarger? The front and rear standards are parallel to one another; I just need to get them parallel to the base.

Jason

 

[ic-racer]

Try and get the diffuser close to the negative, but far enough to be out of focus.
McMaster Carr has a number of different "translucent" plastic sheet materials, though I can't say which would be best. Here is another link to translucent plexiglass http://www.delviesplastics.com/translucent_acrylic.htm.

I don't know of an online manual for that, but a number of places sell reprints of Dejur enlarger manuals.

I believe some Dejur enlargers had a coldlight head. If so, finding a replacement tube may be expensive. Or does yours have a socket for an incandescent bulb?

Shimming the column is a good solution. In fact, the Omega manual suggests shimming to alignment (as head alignment is fixed). Also, check out this picture. I make these 'false baseboards' with screw adjustment at the corners. That way I can have any degree of tilt on the baseboard to line up with the head. So, on these enlargers I have both shimmed the column to approximate alignment, then the false baseboard fine-tunes the alignment.

 

[jnovek]

First, here's someone on PN that has the same enlarger --
http://photo.net/black-and-white-photo-printing-finishing-forum/00F3KQ

It looks like it's a Dejur Versatile Professional.

Try and get the diffuser close to the negative, but far enough to be out of focus.

I think it would be fairly easy to put it in the ring where the light source joins the rest of the head -- which would mean that I wouldn't have to touch it when I need to get at the negative carrier. However, that does mean that I couldn't (easily) put filters behind the diffuser. However, this enlarger has a filter holder below the lens, so I suspect that it didn't originally have a filter holder behind the diffuser. In fact, it was probably in the days of graded papers so I'm sure that filters were an afterthought.

McMaster Carr has a number of different "translucent" plastic sheet materials, though I can't say which would be best. Here is another link to translucent plexiglass http://www.delviesplastics.com/translucent_acrylic.htm.

Would a translucent plexiglass be better, or would opal glass? Surplus shed has 5x7 opal glass for $4.

I don't know of an online manual for that, but a number of places sell reprints of Dejur enlarger manuals.

Pffft! Manuals are for wimps! Besides, $15 puts me well on my way to my next box of film or paper.

I believe some Dejur enlargers had a coldlight head. If so, finding a replacement tube may be expensive. Or does yours have a socket for an incandescent bulb?

It takes an incandescent bulb. It's a standard bulb socket; In fact, I originally tested it worth a normal 40 watt bulb. This thing is pretty old -- ~1940s I'm guessing.

So, on these enlargers I have both shimmed the column to approximate alignment, then the false baseboard fine-tunes the alignment.

That's a pretty solid plan. I was worried about shimming it into alignment... A shim and four screws will be easy to ballpark, but it's not exactly precision work.

Jason

 

[ic-racer]

Ok, since its incandescent, a frosted glass may be a better diffuser. I guess it depends on how big of a bulb you use and how hot it gets. Since it's diffuse light, you don't have to worry about a bulb of a certain length or one with no lettering on it. A 'standard' 150W to 100W might be about right.
As a comparison, those Omega 4x5 enlargers use a Fan and a 200W lamp, but they have the filters and mixing boxes which suck light.

 

[glbeas]

The Dejur enlargers I've had were all condensor enlargers. My first one I had to buy new condensors from Edmund Scientific because it came minus the glass from a school. I'd bet some teen thought it would be cool to take home the big lenses and play with them. The glass is nearly identical to a Beseler, you can even use Beseler neg carriers in it.

 

[jnovek]

The Dejur enlargers I've had were all condensor enlargers. My first one I had to buy new condensors from Edmund Scientific because it came minus the glass from a school. I'd bet some teen thought it would be cool to take home the big lenses and play with them. The glass is nearly identical to a Beseler, you can even use Beseler neg carriers in it.

I'm pretty sure you're correct about this.

Clues:

1) If you look in the picture on the PN thread I linked about, you can see something between the vent holes. I don't have that -- which was pretty obvious when I got the thing together and turned it on tonight and, gee, light came pouring out of the vent.

2) In this PN thread, someone is looking for a condenser.

http://photo.net/black-and-white-photo-printing-finishing-forum/00BIa8

Since I don't have the $$$ to drop on a new condenser, I'm going to have to toss this back in storage and pont my anxious MF/LF negs back to the scanner. At least I know what I need if I ever have the itch and the cash to make this go.

Thanks, everyone, for your help!

Jaosn

 

[mike c]

Keep checking local Criagslist if you live near or in a large city. Some thing will turn up for cheaper than what you have to do to fix the Dejur(that was my first enlarger I had)

 

[Rick A]

Hi!
Do NOT use plastic for the diffuser--when you project light through it, it produces an (albeit slight) amber hue, which could adversly affect your contrast, and or print times. Opal glass is not that expensive. Besides, considering how much you have invested in the machine, almost any price would be a bargain.

 

[ic-racer]

Nothing wrong with converting it to a diffuser enlarger. You are 99% there. Any bulb and a piece of diffusion material and you are ready to print!

 

[Jim Jones]

The 4x5 DeJur I regularly use (like the one in the photo) has a chimney above the condenser lenses that extends above the bulb and shields the light from the vents. Perhaps this could be improvised from stove pipe or metal drain pipe. My spare DeJur is a cold light version, with flashed opal glass sitting on the casting above the negative carrier. While ground glass may be more readily available, it gives less even light than opal glass. If you have to use ground glass, a second piece with the center ground with valve grinding compound might correct for this unevenesss. I shimmed the post where it meets the baseboard to make the column vertical. There are two rollers on the back of the head that contact the column. They are on eccentric shafts for front-back alignment. A properly set up DeJur is a fine old enlarger. Even the original lens came fairly close to a much later El-Nikkor in performance. Mine seems to be sturdy. The lack of a filter drawer for 6x6" filters is its biggest drawback.

 

[Steve Smith]

Pffft! Manuals are for wimps! Besides, $15 puts me well on my way to my next box of film or paper.

I like the way you think!


Steve.