Advanced daylight tank for sheet film - survey

[Jeff Dexheimer]

Pretty positive responses so far. To answer a few of the questions...

1. I don't do stand development myself, but from your description, it would allow stand and semi stand development without any problems.

2. I don't mean to agitate anyone (ha, pun intended) but I don't want to be too descriptive on its workings until I have filed for a patent (if I get that far with it).
3. The amount of chemistry needed would be 1 liter only if developing, say 10 sheets in rodinal. Fewer sheets would require less chemistry.
4. I almost forgot. Flow rate is an important consideration. The design allows for an extreamly fast fill and empty rate. Of course, since it is only in the concept stage, I cannot do more than give hypothetical flow rates, but think a Patterson tank or slightly faster. I have never had a problem with uneven dev in one of those.

Based in what I am hearing, I think it's time to build a prototype. If all goes well, I'll start doing some I depth market research and see what happens.

[Andrew O'Neill]

I also like my BTZ tubes, but of course they are not daylight. I would definitely buy it to try it out.

BTZS tubes are daylight. Of course you load them in the dark like all daylight systems, but develop in the light. You can even keep the light on in the stop and fix. I do all the time.

[the smiling gecko]

absolutely, positively in for an alternate system to develop 4x5 and 8x10.

[WayneStevenson]

" I don't mean to agitate anyone (ha, pun intended) but I don't want to be too descriptive on its workings until I have filed for a patent (if I get that far with it)."

Not to be too cynical, but you're wanting to patent a process for a niche hobby market that arguably is getting smaller with every passing month? In terms of photographic processing techniques, you will be hard pressed to come up with something that hasn't already been patented. Over 100 years of the world's best minds worked for the best companies to put out what is no longer being manufactured. It is going to cost you far more to have someone search through patents, than you probably will make back in profit.... Just a thought.

Your market is small and realistically will probably only supplement your income from your day job or retirement.... I personally wouldn't worry. I would be more open with your idea to ensure it is sound. And a lot of us have experimented a lot to make our lives easier. So someone here may be able to share their own experiences down that line.

Have you manufactured a prototype yet?

[djdister]

I would tend to agree with Wayne. There have been a lot of designs created over the years, and it is hard to believe that you have come up with something truly different. We have round tanks, square tanks, trays, dip tanks, daylight tanks, tubes, and drums. The only thing that could possibly be different would be the equivalent of a covered tray, which is really just a reclining version of a skinny dip tank. I've got a version of a 5x7 daylight dip and dunk processing tank - the film and hangers hang in a daylight tank with lightproof but not liquid proof baffles at the bottom. Once the film and hangers are loaded, you can just dip the whole film tank in 3 successive baths.

Anyway, I seriously doubt the claim that this single tank could facilitate differing process times for the sheets within it. You've described a holy grail of requirements, but I wouldn't put any money down until I saw a concept drawing at the very least. Maybe others are a bit more free with their money though...

" I don't mean to agitate anyone (ha, pun intended) but I don't want to be too descriptive on its workings until I have filed for a patent (if I get that far with it)."

Not to be too cynical, but you're wanting to patent a process for a niche hobby market that arguably is getting smaller with every passing month? In terms of photographic processing techniques, you will be hard pressed to come up with something that hasn't already been patented. Over 100 years of the world's best minds worked for the best companies to put out what is no longer being manufactured. It is going to cost you far more to have someone search through patents, than you probably will make back in profit.... Just a thought.

Your market is small and realistically will probably only supplement your income from your day job or retirement.... I personally wouldn't worry. I would be more open with your idea to ensure it is sound. And a lot of us have experimented a lot to make our lives easier. So someone here may be able to share their own experiences down that line.

Have you manufactured a prototype yet?

[DrTang]

put me down for a 5x7 one if it can do stand developing


I myself was about to think about (yes..about to think about) making some kind of box to hold 3 5x7 hard rubber tanks so I could stan develop 10 sheets..say daylight.. but if you come up with something.. that would make my life easier considering my carpentry skills

[Myxine]

I'd definitely be interested in a 4x5 and even maybe a 8x10. Since developping 8x10 sheets is the limiting factor for me right now to jump a higher format, I'd be very interested.

And if you're doing a market study, I'd be interested even if there was much less sheets stored in a tank (say - 2 I prefer to process slowly but carefully)

[gevalia]

I'd be interested in a 4x5 tank.

A few comments:
1. Just have people sign an NDA. I was able to get a patent 10 years ago and have applied many times since and have successfully used NDA's. An NDA route is a good one.
2. The deal breaker for me is how quickly the tank drains. One of the daylight tanks I played with took 11 seconds to empty. That is a lifetime.
3. I now only use an HP-Combi tank for 4x5. For safety, I only load 4 sheets at a time max and I do stand and semi-stand as well as divided developers (pyro). Even if it did 10 sheets, I would never do 10 at a time. I would not risk 10 negatives at once and this has nothing to do with tank design. But I like that it will not take more than 1 liter of developer.

Also, give some thought to a parts catalog. One think I liked about the HP-Combi was that I could buy individual parts and over the past few years I have stocked up on replacement parts since it is now out of MFG.

Good luck!
Ron

[koh303]

2. The deal breaker for me is how quickly the tank drains. One of the daylight tanks I played with took 11 seconds to empty. That is a lifetime.
I do stand and semi-stand as well as divided developers (pyro).

If you do stand development why is 11 seconds a lifetime?

[propellerhead]

I'll Bite,
Sounds like a great idea, keep us posted Jeff. $80.00 is fair enough.