BTZS film tubes

[Graybeard]

The BTZS tubes are a clever idea but their usefulness may depend on the film format which you process and the ambient temperature of your darkroom.

I'm in northern New York State and my darkroom (quite a nice one, BTW) is in the basement of an old farmhouse located on the side of a hill - the basement is below grade. With the exception of July and August, I have to heat the darkroom in order to reach an ambient greater than about 62F. A superior wine cellar it is, but a chilly darkroom it is as well. Eddie Gunks is south of me.

I do my processing in a surplus (eBay source) laboratory constant temperature bath which holds 72F +/- 0.1 F well (quite the thing for 35mm in Nikor tanks also). The BTZS tubes are intended to be used floating in a tank (tray) of water in order to maintain temperature during development. I'm not at all comfortable with the temperature variation that will occur if development is in a pan of water which relies on (my) room temperature for temperature regulation (several degree F cycle).

The 4x5 BTZS would fit (just) into the CT bath that I have and all would be well, temperatue wise. 8x10 BTZS tube are about 14" long and are simply too large for my temperature bath.

What works for me is use of film hangers and immersing the developer tank in the laboratory constant temperature bath. Temperature swings of +/- 5 F are unmiportant for the solution chemistry susequent to development and I have those tanks in the sink, their temperature following the darkroom ambient. Negative scratches just aren't a problem with the hangers.

I tend to process negatives in lots of 25-35 at a time (4x5, 5x7, 8x10), so the low solution volume requirement per negative advantage of the BTZS tube is lost for me, given the way that I work.

I'm a retired physical chemist. While I admire the ingenuity of the BTZS tube approach to film processing (and I have some tubes here) I feel that I have better control with hangers and tanks.

Your mileage may vary, of course.

[photobymike]

ok ok i had a chance to use some BTZS tubes. i used them in my friends darkroom. I liked them maybe for color neg film but the tray only held 6. i can do 24 sheets of film with my jobo 2500 tank system at the same time. And i dont need a darkroom ... except a harrison tent. The tubes are cheaper and current tech and available. I guess the BTZS tubes would have to be a second choice for me. I prewash all my film. Thats hard to do with the tubes without a darkroom. My film developing work flow has been refined by me over the years, and hard to change i guess.

[Professional]

Sorry to post here, but i've got that BTZS today and i really don't know how to use it either from youtube video clip or the included instructions manual, the video clip is a bit not so detailed step by step for me, and the manual is not so straight forward and my English is not that good to understand all the steps/procedures on the manual, so i hope i can find a link or help somewhere about how to use this BTZS without problem.

[RPippin]

When I first starting using the BTZS tubes, I wasn't very happy with the results. Uneven development, general poor quality. Lately I've had great luck with the tubes for 4X5 as well as 8X10, and what I've done different is to presoak for a good 5 min, with constant agitation first. After doing the standard procedure with stop bath, sometimes just water, I take the film out and put them in stainless hangers to fix. I've done this with the lights on and have no fogging. Being a little more careful with the film when loading in the hangers has prevented any scratching. I also shake the tubes with the presoak and developer a bit as well. Check out the videos on the procedure and follow them to see how they turn out.