I have just found a mint 4x5 holder for the 5x7 Nega carrier, this means printing with the glass removed from the Nega as the metal plates of the lapfe take their place.
I have read, (here on LFPF somewhere) that the Rodagon enlarging lenses are designed to be used with and perform best with glass negative carriers. Does anyone know of this is fact, personal opinion of some or urban legend?
I have always stayed away from glass carriers due to the addition dust and care required when using them.
All enlarging lenses were designed for glass carriers. A Negaflat is not the same as glass and will not give the performance of glass. Equally important is a properly aligned enlarger and printing within the optimal aperture range and magnification range of the lens.
Why would you think that the dust goes away when you stop using glass carriers? And what extra care - other then cleaning them? After all. you have to remove dust from the negative before you print.
Good morning Bob,
Thank you for the reply.
It is not that I think dust goes away with a glassless carrier, it has just been my experience that there is less spotting to do when using glassless carriers with both my Leica v35 or my Beseler 45mx.
Currently I am using a glass carrier on my Durst 138 (condenser, for the first time in a very long while, but the prints are so beautiful I am not in the rush I once was to convert to cold light or diffused light sources) and do find an increase in the amount of dust that needs spotting. I have not had the time to print with the Lapfe 4x5 mask in the Durst yet. I am using a current Rodagon 150 for 4x5.
It is not a monumental amount of dust, and slowly I am reducing the dust with each step and helpful tips sent along by LFPF members. I have grounded the enlarger directly to the electric panel, placed a small humidifier in the darkroom and will soon install an electronic air/dust filter.
Why bother with a good enlarging lens if your film doesn't stay flat? Glass carriers are a
must if you expect precise results. Here's how I do it: align and focus the enlarger very
well, then focus just on the emulsion at a relatively wide aperture, stopped down just enough to bring the enlarging lens into critical focus. That way the glass will actually prevent dust from coming into focus unless the dust is on the emulsion or inner surface
of the glass itself. I always clean such things in a bonafide cleanroom, with an air cleaner nearby, triple filtered compressor air, wearing a dacron cleanroom smock. All
surfaces are sponged down first. And I have a machinists inspection light as well as a
light box handy to check for residual dust. There are also distinct tricks to learning how
to clean the carrier glass properly. Dust is relatively easy to control if you spend the
effort up front.
Bob,Originally Posted by Bob Salomon - HP Marketing
I have always been know to make very nice prints, generally moody and gritty prints of urban scenes, but I am trying to tighten up the darkroom as I move to this new setup and printing larger negatives (5x7 and soon 8x10 negs with a Rodagon 360)
I did a quick search and did not find a definitive answer (many references to the print size, 2-10x with 6x being optimal for the 150 and 2-8x (2,5x) for the 360), what is the optimal aperture range on the 150 and 360 Rodagon?
General rule of thumb I was taught and have always followed on a 135 or a 150 is three stops down, or 16 plus or minus a half stop depending on the neg.
Does that sound reasonable?
Allen,
If you are using Rodagons then 8 to 11 will be best. If Apo Rodagon N lenses then a stop larger will work.
150 optimized for 6x and designed for 2 to 10x. 360mm optimized at 2.5x and designed for 2 to 8x.
As a comparison the 150mm Apo Rodagon-N is corrected for 2 to 15x and is optimized for 6x and the 360mm Rodagon G was optimized for 20x and corrected for 8 to 30x.
If space is a concern the 240 Rodagon is corrected for 8x10 and has the same magnification range as the 360mm and the same optimization and the 120 Rodagon WA will outperform the 150 Rodagon and is corrected for 4 to 15X and is optimized for 6x.
Except for the 150mm Rodagon all of the other lenses above are out of production.
That's why I haven't used a glass carrier - no clean room!
I understand most of us don't have a clean room type darkroom but there are a few things that can be done to improve negative cleanliness with respect to dust. They have been mentioned numerous times in threads here.
1. Clean the darkroom. Remove litter from open shelves so wipe down is easier.
2. Clean the darkroom. Vacuum and wipe down. (Cheap to do).
3. Humidifying the room during dry air conditions helps. (Cheap to do).
4. Wear a lint free lab coat.
5. Get a recirculating Hepa filter; or a couple if necessary. (Very effective).
6. Load your film in the carrier in a laminar flow hood or equivalent. You can even
make a load station using a cardboard box, a Hepa filter unit from Home Depot
and some dryer tubing. This will be the most effective thing you can do for
ultimate dust reduction using glass carriers.
7. Use a filtered air gun to blow dust off film.
8. Print using diffusion head.
If you effectively implement all of these above you will have essentially zero dust at the film plane of your glass carrier and be able to print as hard as you might like.
As Bob says above, enlarging lenses are designed to image a flat field. Any curvature in the film plane will result in some image degradation at the easel.
Nate Potter, Austin TX.
My own experience with these lenses at best aperture exactly matches Bob's advice.
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