Fuji GSX690 Pro enlarger - first experience and silent musings :)

Hello friends,

today I've spent almost all my salary - buying, after all, that old Fuji enlarger. Looks like I am lucky - that's the most solid-built machine I've ever seen, Durst is no comparison I've paid $320 total, for two new Fujinon-EX lenses (105/5.6, 50/2.8), a set of deluxe glassless neg carriers for 35mm, 6*6 and 6*9, a control unit (100V AC, useless), and the body with dichro colour head. I've managed to switch from those unusual 100V 150W lamps originally used to 220V 100W household type lamps - with the same kind of reflector, but available everywhere for $1 apiece

My first experience with it was quite pleasing - it's very easy to operate, though it's on a dark side for me... I've never used a diffusion head before, but I am still able to focus it sharp though it's rather difficult at f/5.6. Are all the different diffusion heads always dim? I seriously doubt that 100W instead of 150W made the real difference The exposure times are usually under 1 minute, so I consider them as quite normal.

The picture, however, is TOTALLY different from what I'm used to with my condenser Magnifax - they're much more plastic, with almost no Callier oversharp and contrast. Yes, and the Fujinon EX lenses are great too - very sharp even when open wide... these can be reverse-mounted after removal of front ring, can't understand why should I ever need this with Fujinons being apparently a 6-element almost symmetrical lenses?

I am really very glad that I've purchased it - I were able to fix the lamp issue, and the rest is quite easy. Some experience, and I think I would be able to make better prints with it than ever before - something inside tells me that for my usual subjects the diffusion head would work better than a condenser. And it's better for colour, right? And no more shuffling of filters...

Cheers, Zhenya

I'm not sure which one it is exactly in the Japanese lineup, but usually Fuji's monsterous enlargers are quite popular over here. I have the lastest of the 690 series, a condenser-head type OEMed by LPL probably only available in the domestic market.

And I do use a 90mm six-element lens sometimes. It's so smooth.

let me know if you ever want to sell the Fujinon EX 100mm

Somebody else just sold me a Fujinon EX 75mm that they had posted about years ago. Hope is eternal.

eumenius said:

My first experience with it was quite pleasing - it's very easy to operate, though it's on a dark side for me... I've never used a diffusion head before, but I am still able to focus it sharp though it's rather difficult at f/5.6. Are all the different diffusion heads always dim? I seriously doubt that 100W instead of 150W made the real difference The exposure times are usually under 1 minute, so I consider them as quite normal.

Click to expand...

I've got to tell you, I use both condenser and diffusion type enlargers, and hands down I prefer the diffusion type. I don't care for the callier effect, and the advantages gained in the areas of small dust and scratch suppression far outweigh any other so called advantages of the condenser type. However, diffusion type enlargers are far less efficient at getting light down to the baseboard. A lot of light that would otherwise be be focused directly onto the negative by a condenser, gets lost as it is spread around in those mixing chambers. So you might want to consider using the 150 watt spec. lamps if you're finding the baseboard illumination a bit dim.

Let me relay an example. My big condenser enlarger is a Beseler 45 using a single 150 watt / 120 volt standard tungsten lamp. My diffusion type enlarger is an Omega D series machine with the Chromega II lamp house using a single 250 watt / 24 volt tungsten/halogen lamp. Exposure times for both machines are close enough for a given negative to call it a wash, yet the raw light output from the 250 watt lamp is far brighter. All that extra light is going somewhere, but it sure isn't going through the negative. I could make the diffusion head more efficient by using a mixing box for a smaller format negative, but I don't feel like running yet another set of calibration tests for something so trivial.

Another thing you might want to consider is the color temperature of the lamps you are currently using. "Household" tungsten lamps burn at a considerably lower color temperature than photo enlarging lamps, giving off a more yellow light. Compensating for that is a trivial matter when you have built in C/Y/M filtration. Simply dial in a little more magenta and you're done; but reaching the hardest possible paper grade will not happen. Trust me on this one. Been there, done that.

eumenius said:

I've managed to switch from those unusual 100V 150W lamps originally used to 220V 100W household type lamps...

... dim? I seriously doubt that 100W instead of 150W made the real difference

Click to expand...

Actually, it makes a real difference. Not just the wattage; with incandescent bulbs, the efficiency makes a big difference.

First, as the lamp voltage goes up, efficiency goes down! This is why projectors that use incandescent (halogen) lamps, use a transformer, usually 24 V. In this way, a 24V 250 watt bulb can give as much light as 220V 400W bulb would give (approx.), with less heat and wasted energy. Of course, if the original used 100V bulb, not 24V, the difference is not that high but it's still there.

Second, as the lifetime goes up, efficiency goes down! "General" illumination bulbs have a lifetime from about 1000 to 4000 hours, projection lamps as used in enlargers etc. as short as 50 hours. This makes an even bigger difference.

Third, the projection/enlarger lamps use more "advanced technology" to further increase the efficiency, such as xenon gas inside the bulb, or an infrared-reflecting coating on bulb glass.

Fourth, the projection angle is different. More light is wasted if the projection angle is too wide.

Long story short, a "general use" 220V 100W bulb may be comparable to a 50-Watt 100V enlarger bulb. Even less, if there is a projection angle mismatch. Live with it, with longer exposures, or buy suitable bulbs - if available. You also could modify it to use 24V bulbs (24V projection or enlarger lamps are widely available), and buy a 24V transformer.

Color temperature is directly proportional to the efficiency mentioned - the more efficient bulb, the "whiter" the light.