Condensers and light pipes don't absorb much light energy as heat. Diffusers do absorb quite a bit of light energy as heat,
Okay, some of that is starting to make sense...but since I'm a relatively low-watt bulb in and of myself, I need some science explained to me:
How does the positioning of the condenser in relation to the diffusion material impact efficiency from the perspective of the negative, and therefore the print?
It seems that if any given amount of light traverses a given distance with a constant amount of interruptions along the way - i.e. the condenser lenses and the diffusion plate - then there should be no change in the energy that's transmitted, no matter where those interruptions lie or in what order they're arranged...but if that's not what actually takes place then what seems correct must be wrong. So: would it be more correct to assume that placing the condenser adjacent to the source is effectively changing the amount of light that's actually being transmitted to the remainder of the system?
Also, how would a diffused light source impact this arrangement?
When I was referencing the color heads, I was specifically talking about the ones that introduced some kind of actual colored light; the incandescent ones weren't really in that category, to me. As I said: I have a garden-variety condenser head, and I know it's a "color" head per Beseler, but it really kind of just isn't.
Condensers and light pipes don't absorb much light energy as heat. Diffusers do absorb quite a bit of light energy as heat,
The Beseler-Agfa Colorhead incorporated C-M-Y filters that were dialed in (0-199) -- just like with the quartz colorheads -- but it used an incandescent 250w projector bulb -- and a standard condenser. How does that not provide "actual colored light"?
And whether the color is provided by passing/removing white light through built-in, easily adjustable dichroic filters or manually slide-in CC filters, they are accomplishing the exact same thing in exactly the same way.
Sundowner - most enlarger heads don't give even illumination over the full range of potential applications. Ideally, you'd need a whole set of convex diffusers to offset the illumination falloff factor of different lenses, even at different f-stops. Beseler probably made a calculation concerning what a typical lens would represent at the most likely f-stops. Longer than "normal" focal length enlarging lenses have much less falloff than normal and wider than normal lenses, just like with camera lenses. And in most cases, the falloff is worst at maximum aperture, then steadily improves a by a couple stops down, where typical enlarging lenses enter their best performance zone.
Beseler chose a thick moulded white acrylic element rather than having each one ground to specification, which would have been a tedious chore to say the least. But there are higher transmission ways to do it too.
With so many of these things, engineers come up with interesting ideas, but then these innovations turn out half-baked when all the compromises of cost and outsourcing get factored in. That certainly isn't unique to Beseler or even any one industry. It drove me crazy when I interacted with power tool designers prior to retirement. Really clever ideas got watered down to uselessness in order to meet the price point parameters set by the marketing monkeys, whereas the kind of professionals who could really use those kinds of tools if they reliably worked would have happily paid a premium price. I got so fed up that I focussed more and more on German engineering rather than the usual suspects. Contrary to the typical marketing philosophy, the more expensive the equipment was, far more of it sold, and it was much more profitable to everyone, a win-win - ourselves as the sellers, and the end-users too because their work became dramatically more efficient.
The analogy being - how much actual prototyping and thorough personal testing was actually done by some of those later Beseler head designers. Nowhere near enough in my opinion. I hope that has improved, but based on sheer experience, I remain a bit skeptical. End of rant.
When I was talking about an "actual" colorhead I was referencing the dial-operated, tri-color light sources that use either an internal/integral system of subtractive filtration or discreet additive spectra in order to generate a specific and controllable output that relies upon no external filtration to produce the desired result.
Take a look at the picture of the Beseler-Agfa Colorhead. You will see three dials -- one for each color filtration level (C-Y-M) that you dial in. It works just light the quartz colorheads except it uses an incandescent bulb instead.
Whether your fingers turn a dial to insert filtration into the light path, or your fingers directly insert filters into the light path, optically it is exactly the same thing.
And the filters don't really care whether the light source is incandescent, quartz, halogen, tungsten, LED, sunlight, etc.
You should check out Post Exposure by Ctein (available somewhere to download pdf). Most of it is the usual stuff but he does experiments to demonstrate the principles.
So, is there a light source that's not a color head, by that definition?
Cold light heads, as far as I know, don't allow any filtration either.
So any enlarger can be a "color" enlarger, but not all enlarger heads are color heads.
On the original topic: it seems that unless there's an actual point source - like, a bare bulb filament - and absolutely no diffusion elements in the mix at all, then technically most enlarger systems with lenses or refractory elements are actually hybrid condenser/diffuser systems of one ilk or another. That doesn't really seem to be the way we're using the term
Thought: perhaps the practical deployment of each type is more the basis for differentiation and typology than their respective optical arrangements.
I think it would be fair to say that there's no proper or universally-correct way of introducing diffusing elements into the light path; they can be placed pretty much wherever, with varying effects.
Are you saying that there is no inherent physical provision for a filter in cold light heads, or that the light output of the lamp does not work with filters?
It's a somewhat misleading assessment. Prior to modern colorheads, filter drawers on tungsten bulb beehive enlargers would accept Y,M,and C sheet filters of various cc gradations which enabled color printing, if clumsily. Or R,G,&B sheet filters could be used sequentially (not simultaneously) to allow color separation work for sake of processes like dye transfer printing.
But cold light heads are basically bent fluorescent tubes, and the specific phosphors determine the output color; but this is never a true "blackbody" continuous spectrum light source like a halogen bulb or sunlight. So it would be unwise to select a cold light for color printing per se. Certain types like the V54 Aristo output blue-green light specifically for sake of improved VC paper results; and one can trim out either the blue or green component by using the opposite filter, green versus blue, or else just use the light "as is" for more ordinary results, but not realistically for actual color printing.
My own V54 8x10 cold light is the high-output 12X12 variety, so I installed it with the ability to have an overhead neutral density filter in place if necessary to slow exposures down. It was intended to do enlargements with supplementary contrast masks in register with the original 8x10 shots, as well as easily print with a deep blue 47B filter in place, or else even a deep green 58 or 68 for sake of split printing, with a lot of reserve lumen capacity. I use good quality glass filters on the lens itself. There is no evident diminishment in the visual quality like would be the case if polyester filters or polyester "lighting gel" sheet material were used beneath the lens.
I think the typology is based on the presence of one or more condensing lenses. In that sense, it seems reasonably conceptually clear, although it leaves the distinction between a point source and a non-point source system somewhat...diffuse.
Try it out and see. You'll notice that there actually are wrong places to put them.
Does that help? I guess not. As you're finding out, perhaps we're not really dealing with typologies here, but rather with somewhat informal taxonomies.
The V54 Aristo is a single tube set, with blue-green output, and NOT two separate grids overlapping, one blue and the other green, like the Zone VI cold light, for example. Its own unfiltered "white light" is therefore not white at all, but is very well balanced by itself for what was once classified as Grade 3 paper. For split printing, supplemental B vs G, or M vs Y, filters are necessary. Graded papers were of course mainly blue sensitive, while ordinary tungsten sources are rather warm yellowish until modified via filtration.
What this points out is that enlarger light sources exist on a continuum from very sharp to very diffuse -- in some ways similar to an artist's various paint brushes. And while most photographers might stick to only one light source, many have several heads and use them as needed.
Pictured: I'm always so late to the party.
In my old darkroom, I had twin 23C chassis side-by-side. One was a standard condenser, and the other was Aristo-fied, with the housing up above the filter drawer. I often went back and forth between them, looking for specific results...or just making comparisons.
It's not you, though. The funny thing is that if you do a web search on the distinction between condenser and diffuser enlargers, you find a whole lot of stuff that turns out to be about confusion enlargers instead. The clearest explanation I had read previously was, I think, in a Durst enlarger user manual. Go figure.
I'm not the only one that has two enlargers for this reason. For me, one has a condenser on it (most of the time), and the other a diffusion head (most of the time), so it's easy to switch from one to the other depending on the negative. I'm lucky to have enough space -- it wasn't always the case.
SOME people even have MORE than TWO enlargers -- can you image that?
That's what I'm calling them from now on.
Yeah, I don't have that space anymore, myself. In my old darkroom I had room for the two, and also an area for a third one, which I used for parts and repairs.
Nope, can't imagine that. Not at all. Two is definitely the most I can imagine. All numbers past two do not exist. In no way, shape, or form do I possess more than two enlargers, most of which do not work. It's just the two 23s, and that's all. Just those two.
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