Maybe consider a ordinary ND filter screwed into the front or back of the lens?
Maybe consider a ordinary ND filter screwed into the front or back of the lens?
Demonstration by example is the best way to observe the behavior. With a 300mm lens on probably any of your big enlargers, compose an image about 8x10 in dimension (you will need an enlarger with over 600mm bellows draw). When you try to focus this you will find there are two focal points very close to each other. You can easily see the image getting sharp, then blurry, then sharp again as you focus the lens stage up and down.
As you raise the head, the two focal points of lensboard travel get farther and farther apart. In one case now you start making a reduction and in the other case you start making an enlargement. So, yes, as you raise the enlarger head when making reductions, the image gets smaller.
You can't usually observe this with 4x5 enlargers because they don't have enough bellows draw.
I lamp mine with ENH bulbs, 1000 watts instead of 1250 with ELH bulbs and 5 times the bulb life. 175 hours vs 35 hours. No need for ND filters.
Yup, IC, just wait until something happens to those 1960's electronics that you can't fix. Then you either have to rewire the whole thing, or you have a very nice paperweight! And let's not talk about bulbs and reflectors. I know you have spares, let's just hope they out last you! The 5108 uses plain 120v projector bulbs. Available new or NOS at auction. I think I have a couple of 100's! Just ribbing back.
I could hold down a lot of paper.......or you have a very nice paperweight!
Wish it were a density adjustment, but like Terry said, it just moves the filters out of the way for focusing. It was interesting when focusing and having the two focus points with a 240! L
Last edited by Luis-F-S; 1-Oct-2018 at 07:23.
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