My experience is similar to that mentioned in Post #7 by Thomas.
I will only summarize my experience with this format (6x7cm neg) and 20x24 prints:
You will need a 90mm enlarging lens - a 75mm will not cover 6x7 - a 100mm or 105mm would be even better. These lenses may or may not allow you to project a 20x24 image onto the baseboard, especially if cropping is required; as already mentioned, there are ways around those limitations.
20x24 trays take up a lot of room! Toning and washing has to be done pretty much one print at a time unless you have a 20x24 archival print washer (a monstrosity). You need a lot of chemistry - I use 3 Liters of solution per tray, some trays with deep bottom ridges require more.
Handling prints - moving them from one tray to another, takes slightly more effort to avoid paper damage; I have creased a few.
A 6x7 negative has enough information to print onto 20x24 without degrading the image, especially if you are using films like T-max, Delta or Fuji ACROS. I have printed a few 6x7 and 6x9 negatives to this size with very good results.
Sometimes you need to print large to see what size limitation you image has - not every subject matter looks good printed large.
Printed and framed my first prints of a local scene - the huron river and bridge landmarks nearby at a metropark. Went with 16x20 as suggested and am enjoying the process. here are some thoughts that may help others in future perhaps.
The Ventillation I installed still requires additional work even after the $100 invested. The newly installed outflow requires more inflow than my space affords naturally for sufficient change over so will need to pipe in air; printing to this size really fills the space with fumes. I installed an 8" 500cfm inline duct fan and descended two 6" drops to just above trays. The suction is weaker than i anticipated, barely holding a piece of paper in place when covering the inlets.
For water, I was able to use an existing cold water outlet and bought an inexpensive hot plate to warm the water in an aluminum pitcher in order to mix developer batches without bringing water in as I have done previously. I was given trays by a friend as well as two plastic 2000ml beakers needed to make sufficient quantities of dev and fix; it takes 2x as much minimally.
I am on septic so storing all that spent fix in 5 gal container until disposal is a pain and humping remaining water from the session upstairs is tiresome until i install final drainage into sump.
I am hawking for a new enlarger lens; balancing max column height with focal length. I did figure out an issue to allow me to print imperfectly for now using 75mm lens with other members input under a separate post.
I like the feel if not the cost of the double weight fiber paper i ordered; it holds up well to my manhandling. I can store in the box it came in being careful not to let it open accidentally and put vertically in the closed counter.
Doing more than a print or two at a time or with any frequency would require me to solve the print wash problem, but for now manual soak and change during course of an hour is sufficient.
I also bought a steel sheet sufficiently thick to work as my easel. i sprayed it with polyurethane to keep it from rusting/clean and used painters tape to mark the outer dimensions of the paper. I then bought a strip of magnet and cut it to required lengths to hold the paper flat and it gives me a small border too; all for $25.
Tons of issues to perfect over time including spotting as mentioned and others, but am on my way
The joy of printing the ratio afforded by 6x7 neg is great. I want to look further into frame options as not sure i like 18 x 24 frames with 16 x 20 prints ; at least in landscape orientation and even matting borders. Maybe portrait orientation prints with greater bottom border relief would be appealing.
But Going from 11x14 to 16x20 is certainly a major overhaul that magnifies every step in the process. Great if you like a challenge, have the time, afford the investment, and have the wall space to enjoy the result. Has been a rewarding next step in the process. thanks again for all your input.
I only know of a few six-element 75mm lenses. Koumaron, and two Fiujinons. To know for sure if you have coverage for a 20x24 it would be wise to invest in a Peak-1 magnifier. If you don't have that magnifier, you can make little prints of the 4 corners and center of a 20x24 projection and compare them. You won't need 20x24 trays or paper to do that.
[Emphasis added by me]
Originally Posted by sharris
I would be very careful about using aluminum for mixing chemistry. It may react with some chemistries.
Otherwise, I'm glad to hear that you are enjoying the step-up in size.
I've decided that I'd print all my very best images on 20x24, a few months ago. I'm a 35mm shooter. And since then, I've printed about 150 20x24 FB prints.
The results are outstanding and sharp. Just excellent.
OK, I admit to using a Focomat IIC and a brand new and well performing 60mm focotar f4.5 and shoot almost exclusively with Leica's finest lenses. But even with the old glass and some Nikkors I'm quite blown away. But I'm always after a feeling, a mood, a character rather then perfection.
Who says that 35mm film cannot go that big? :) Here's a shot of a 20x24 print shot with a F100 + 105 f2.5.
..quick note..the aluminum is only for straight water to warm it up...don't mix anything in it and that is a very good point!
Balls that's some good work. What'd you do with the edging there?
Originally Posted by NB23
Thanks Brian and Klainmeister,
I hope you saw the man hiding which is what makes the image, IMO.
The edges are from the negative holder being slightly wider then the negative itself. I never crop my images so all my prints have this border that I personally find quite appealing.
I don't want to hijack this thread with my images but they just go to show how printing 35mm as big as 20x24 can be beautiful. Here's another one, shot on a Minolta X9 + 50mm f1.7 some 15 years ago.