Durst L1200 DIF1 & DIF2 diffusers on Femobox 450N

**Rob Champagne** · 6-Jun-2008, 18:21

I have been using a DIF1 diffuser in my L1200 since I've had it. I also have a DIF2 which I've never used. The DIF1 is only half the thickness of the DIF2 so I have always assumed it gave less diffusion and therefore sharper projection than the DIF2.
However, I just held them both upto the light together, and if anything the DIF2 transmits more light and is fractionally less diffuse than the DIF1 which has a milkier perhaps more dense appearance even though it is only half the thickness of the DIF2.

I justed tested both of these diffusers on my densitometer. How accurate the actual densities are is possibly suspect because of the thickness of the diffusers. However these are the figures:

DIF1 = 0.85
DIF2 = 0.89

Thats less than 1/6 th of a stop difference even though the DIF2 is almost twice as thick as the DIF1. This leads me to suspect the DIF2 gives less diffusion because its twice as thick but transmits almost the same amount of light.

I will have to test this although I have been getting sharp prints using the DIF1.

Anyone know whether the DIF1 or DIF2 was intended for sharper projection and whether there were other thickness diffusers?

**Filmnut** · 6-Jun-2008, 19:33

I'll put my foot into this, as I've worked with these enlargers a lot (I had a whole printing department with these!) back in the eighties and ninties but my memory is a bit hazy about exactly which diffusers came when.
But I'll give you my best shot at this.
I do not believe that either one will affect sharpness at all. The different diffusers were to correct for light fall off, the evenness from centre to edge, not for sharpness, as we had problems from time to time, with this issue, in certain critical situations, with certain setup's. So the DIF2's were supplied to help with this problem, which to my recollection they were somewhat more even.
For the vast majority of work, you won't be able tell one from the other.
Hope this helps.
Keith