Hello forum members,

I am very new to large format photography, just a few days ago received my first 4x5 camera, a Shen Hao PTB 45. I usually (in medium format) shoot in colour but I got some cheap Efke PL 100 4x5 B&W film to learn to use the new camera and format.

I have processed B&W film before, however only 35mm and medium format. I read about the "Taco method" and since I own several Paterson tanks I decided to give it a try. Attached is a quick test shot I took in my kitchen. I think I should have developed a little longer (I used Ilfosol 3 developer and had to guess the time as I couldn't find any developing time for Efke 100 in this developer), but besides that obviously something went wrong, development is kind of uneven (see attached image).

Any ideas what I did wrong?

Also, I am thinking of trying developing in trays. I have read about this but am unsure if I have understood everything correctly, so here are some questions.
- You place several sheets of film on top of each other in a tray, all sheets emulsion side down, then you continuously take the sheet from the bottom of the stack and place it on top? Do you also rock the tray in addition to this shuffling motion?
- If I only develop one sheet, do I just constantly rock the tray? Is it also possible to place two 4x5 sheets next to each other (opposed to on top of each other) in an 8x10 tray?
- How much developer do I need to use, just enough to cover a sheet (or the stack of sheets) or more?

Sorry, lots of questions... I took some more pictures today but don't want to develop them before I know what I did wrong with the test negative. Your help is appreciated!