For those who have and know about Durst 138 condensers I have an observation. The individual condenser comes in a metal framed container. The lettering on the front handle of that container includes Durst and the condenser size. The lens is mounted convex side up when reading the words on the handle. The condenser is inserted into the enlarger as directed on the top of the housing or head. For 5x7 with appropriate lens a Durst 240 is placed in the bottom slot with the convex side up and the lettering on the handle reading from left to right.
The top condenser is also a 240 and the orientation is convex side down so the two condenser lenses are convex to convex. In my experience this is the appropriate placement for condensers.
Finally; my question is, when the condenser on top is placed correctly, convex down, the information is upside down. The condenser seems to be upside down.
My second question is; I have two 240 condensers and they are convex to convex yet the lettering and numbering is in the correct reading position. How is that possible?
Lastly; is there a "top" and a "bottom" designated condenser and I'm just 'lucky' to have these two if I need them?
Ive looked at numerous photographs of Durst condensers and I haven't seen any like my top 240 condenser. Are they interchangeable and used upside down or right side up? I admit I haven't looked but are the lenses able to be turned in the housing?
Why do I care if it works? A bulb is in, the spotless mirror is in, the condensers are as directed, the lens is mounted on the right disk and the negative in the Glass Durst carrier is in alignment. So why, what if I want to get a 200 or other condenser, how will it fit? Which side up?
So far I have a working condenser and diffusion enlarger setup.
It just appears to be an inconsistency or anomaly.
As far as I know, the front metal tag is just an insert in the carrier frame that supports the glass, and that the glass in a 240 is the same for both the upper and lower condenser carriers positions.
When I had one of mine apart to attempt a repair (broken glass retaining clip from some past sloppy shipping or being set down hard) I screwed up on re-assembly, and put the tag in backwards. So now I have a 240 with nothing on the label but shiny metal - no text.
That side effect of the disassembly reminds me to use the broken clip one only in the convex side up position. Otherwise the glass is prone to want to fall out of the frame when the carrier frame is withdrawn.
It is the glass that does the work. The label is just that, a label.
There should be a plate on the front of the enlarger head that gives you the information regarding what condensers and lens you need for the film size you are enlarging. The pair of 240 condensers are designed to be used for 4"x6" and 5"x7" film with a 180mm or 210mm lens. If you were to enlarge a 6x6cm negative you should have a 200 condenser on top of a 130 and use a 80mm lens. In all cases the convex surfaces should be facing each other.
For the 138's bigger L184 (10x10) sibling that I have, all five condensers have the label reading correctly with the convex side up and flat side down, an they do not look to be changed from the factory configuration, unlike Mike's situation.
So yes, when combining condensers the upper one has the label upside down as you indicated.
If you have difficulty reading it upside down, just pull it out to read it... :D
I agree, I saw a position sheet in the Durst USA site that shows two condensers both convex side up.
Originally Posted by Mike Wilde
Mine has a head that points at the ceiling but when I'm lazy I take an iPhone picture and then rotate it an app. :blink:
Originally Posted by Len Middleton
Thanks guys for all the thoughts and comments.