[filmmaster]

Here are a few questions on enlargers id like a tad of help on.

1. with the modern LED light panel/sheet systems, is it even neccessary to have a condensor or diffusor system?

2. with modern flashlights coming with built in condensor lens systems, its how they go from wide beam to narrow beam... Does a person only interested in 35mm or 110 enlargement actually need to care about a full size system?

3. the fact that my beseler 23c11 lens board uses one hole size, and one size for the enlarging lens, does the fact that the 50mm lens, and the 90 and 105mm lens i have dictate that i acutally NEED tohave huge dimensions in my focusing bellows

[StiffLegged]

1. The enlarger, including its lamp/LEDs is designed for the lighting system used.

2. What flashlights have to do with this I don’t understand, but if you’re only interested in enlarging from 35mm film at the biggest then you don’t need a bigger enlarger for say, 6x7cm film.

3. Your Beseler enlarger’s focussing bellows has to allow enough movement for making small prints from large negatives (with a 90mm lens or longer) and large prints from small negatives (with a 50mm lens or shorter). That’s why there’s a large range of movement. The 39mm lens mounting hole has nothing to do with this.

Have you managed a sharp print yet? It might help those trying to help you if we knew.

[Bob 256]

An LED light panel will always act as a diffusion source. You could design a condensor light source using LEDs but it would have to incorporate a condensing lens and would occupy more space than a panel.

LED flashlights use a positive (often a double convex) lens in front of the LED whose position can be changed to vary the beam width. Think of this as a crude zoom lens of sorts. As the beam is widened, it becomes less bright but covers more angular space. One of these might be used like a (condenser type) light source in an enlarger but a flashlight produces a diverging beam so it would almost always produce a hot spot if used as a light source unless another lens was used to "condense" the light beam to a converging cone of light. Generally, this would make an LED flashlight a poor choice for an enlarger light source.

Your Beseler enlarger uses a fixed focal length condenser lens and varies the distance between it and the enlarging lens being used to get the best cone of light for that given enlarging lens. This distance needs to change or, again, you can get hot spots in the projected image (for example using the bellows setting for a 105mm lens with the 50mm lens). Other enlargers (like Durst) have changeable condenser lenses which are swapped out to match the enlarging lens being used.

When you use a diffusion head (or an LED light panel), the negative receives uniform illumination and there is no "cone of light" being sent to the enlarging lens. Hence, the distance between the light panel and the negative is fairly unimportant (and, one diffusion head can work with different focal length enlarging lenses). Diffusion lighting, however, can produce softer images compared to a condenser arrangement although diffusion lighting treats negative scratches and defects better (making them slightly less visible).

[filmmaster]

the flashlights i was looking at, they all have this little issue of very narrow beams via the built in condensor lens. even patents mention them as condensing lenses.

And i dont think i have met a CREE LED that had a soft spot

---------- Post added 01-07-22 at 11:46 AM ----------

by dimensions, i ame talking about the focusing stage bellows, its bigger then most 6x9 folding cameras had, yet they do finewith no issues. RB67 uses a bellows section barely bigger then the lens mount with no loss of anything.

[ProfessorBuzz]

LED light sources, even if diffused, still have hot-spots. Electroluminscent panels behave better in this regard, but don't put out much light. Your enlarger was designed as a system, and so bulbs, lenses, and everything else really go well together.
They also don't have the same spectral coverage - paper is blue-sensitive, and LED colour spectrum isn't really strong in the blue for most "white" LEDs - usually there is a phosphor to help widen the output spectrum. You would want to check the datasheet of the LED sources you are using. Also, some LEDs have really strong UV output and a phosphor to downshift the output into the red. This can really throw you off, since it's not readily visible by the human eye.

[Bob 256]

LED light sources, even if diffused, still have hot-spots. Electroluminscent panels behave better in this regard, but don't put out much light. Your enlarger was designed as a system, and so bulbs, lenses, and everything else really go well together.
They also don't have the same spectral coverage - paper is blue-sensitive, and LED colour spectrum isn't really strong in the blue for most "white" LEDs - usually there is a phosphor to help widen the output spectrum. You would want to check the datasheet of the LED sources you are using. Also, some LEDs have really strong UV output and a phosphor to downshift the output into the red. This can really throw you off, since it's not readily visible by the human eye.

I believe in LED panels designed for enlargers, red, green, and blue (tricolor) LEDs are used, so they work with photomaterials pretty well and somewhat match their spectral sensitivities. This also allows dialing in of color correction when used for color, and selection of varying "white" output when working with variable contrast materials. You're right that these can produce hot spots but with suitable diffusion layers between the LEDs and the working side of the LED panel, sufficiently even lighting can be obtained. Furthermore, the surface of the LED panel is not at the focus of the negative plane so that provides further "smoothing" of the light output. Tri-color LEDs can also be employed in the conventional "mixing chamber" type of enlarger head for even better uniformity of light output.

---------- Post added 01-07-2022 at 12:16 PM ----------

the flashlights i was looking at, they all have this little issue of very narrow beams via the built in condensor lens. even patents mention them as condensing lenses......................

LED flashlight do use a positive lens which could be classified as a "condensing" lens but its placement relative to the LED causes the exiting beam to diverge. If the LED is placed at the focal point of the lens, the exiting beam will be almost parallel with little divergence ("spot beam"). If the lens then moves away from the LED, the beam will converge as the light does in an enlarger before it reaches the negative and enlarger lens beyond. However, in an LED flashlight (with zoom functions), the lens can only move closer to the LED which causes the light beam to expand and diverge - not what you want for an enlarger light source. You can overcome this by putting another positive lens in front of the flashlight and positioning it so the beam is collected and sent on in a convergent beam, so in practice, a flashlight could be used for an enlarger light source but there are many better choices.

[StiffLegged]

by dimensions, i ame talking about the focusing stage bellows, its bigger then most 6x9 folding cameras had, yet they do finewith no issues. RB67 uses a bellows section barely bigger then the lens mount with no loss of anything.

You’re trying to enlarge small film on to larger paper, not make a small photo on film of something larger. I’ll ask once more if you have managed to make a sharply focused print at all. We’re trying to help you but don’t know whether it’s making any difference at all.

I’m beginning to think we’re being gently trolled and I do hope I’m wrong.

[35mmfilmfan]

I’m beginning to think we’re being gently trolled and I do hope I’m wrong.

Hmmm. Have you looked at his other posts ?

[filmmaster]

You’re trying to enlarge small film on to larger paper, not make a small photo on film of something larger. I’ll ask once more if you have managed to make a sharply focused print at all. We’re trying to help you but don’t know whether it’s making any difference at all.

I’m beginning to think we’re being gently trolled and I do hope I’m wrong.

General Rules for conversations, in person and upon the internet

1. If you do not like or understand the item or idea being discussed, simply walk away and do not say or type anything.

[StiffLegged]

… We’re trying to help you but don’t know whether it’s making any difference at all….

General Rules for conversations, in person and upon the internet

1. If you do not like or understand the item or idea being discussed, simply walk away and do not say or type anything.

It seems we’re not helping then. I hope you find someone who can.

[ProfessorBuzz]

I believe in LED panels designed for enlargers, red, green, and blue (tricolor) LEDs are used, so they work with photomaterials pretty well and somewhat match their spectral sensitivities. This also allows dialing in of color correction when used for color, and selection of varying "white" output when working with variable contrast materials. You're right that these can produce hot spots but with suitable diffusion layers between the LEDs and the working side of the LED panel, sufficiently even lighting can be obtained. Furthermore, the surface of the LED panel is not at the focus of the negative plane so that provides further "smoothing" of the light output. Tri-color LEDs can also be employed in the conventional "mixing chamber" type of enlarger head for even better uniformity of light output.

Agreed - nicely explained. The panels specifically designed for enlargers are quite good, The OP seemed to be thinking of retrofitting things.