I have 20+ yrs of experience in tray developing and Jobo ATL3 usage. I used the jobo ATL3 for years. I did E-6 , C-41, and b/w in it with great succes. Even the E-6 process was impeccable. We did a test everyday to read out the E-6 teststrips and always kept in between balance. The ATL3 came with waterbody that was a sort of bain-marie ( a container holding water on a certain temperature ) which kept the drum that contained the film and liquid on the exact temp.
Filling of either 4x5 or even 8x10 film was really very easy ! But this won't bring you much closer to a solution to your problem. Try some googling on ATL3.
Tray developing is actually easy to do. If necessary keep yr developing trays in another bigger tray as way of bain-marie to keep liquid on temp during treatment of film.
The trick is to slide the sheet of film into the tray and get the liquid asap over the film to avoid developing spots. So what you do is keep the tray in a slight angle. Best is to hold the tray on the front with one hand. Lift the tray slightly, put the film with the upper part into the back ( where the most liquid is now during tilted ) of the tray. Lower the film equally together with the tray and start gently to lift and lower the tray during the complete process of developing.
You can also first make the film wet in ordinary water on temperature for a minute before starting the development. This process also garantees that the fluid is smoothly spread over the sheet film.
I hope this makes sence. Don't be afraid to do it. It works just fine, and is very cheap. Just trays and your liquid. That's it.
Also important is to prepare before you start ! Make sure everything is in place and set to use. That means no stress during the handling!
Good luck !
Over the past 45 years I've developed 4x5's in: 4x5 dip tanks, 5x7 dip tanks, 8x10 dip tanks, a 4x5 Yankee tank, trays of various sizes, and in tubes made for developing paper. I've never had a JOBO, so I can't comment on that. I've basically had good (identical) results from all except the paper developing tubes. I've often had bad results with that approach and have generally stopped doing it.
I've been using a uniroller to process all of my 35mm and 120/220. When I started shooting 4x5, I picked up a 8x10 daylight print drum made to process 2 8x10 prints. I've put a divider in so that it can fit 4 4x5 sheets. It uses about 250ml of solution and produces great results. I think I've spent about $75 on the drums and roller for all of the above formats. I'm developing traditional B&W, C-41 and E-6.
Thanks for all the answers.
I have to give what i have a go first, i tested the trays and got the impressions, so i have to check the tubes and the Combi-Plan tank and see, i really like the MOD option, and i don't think i can get JOBO even if i want.
And also i appreciate the answers talking bout processing color films as well, because i doubt our lab will keep doing color film processing for long time, i asked them about processing 4x5 neg colors and they said they don't do it for less than 15 or 20 sheets, and then one member here said that he went there and they told him they will not do 4x5 color neg anymore, i bought 1 color film sheet box already, so what i can do with this if the lab can't process it and i don't know how to process color film?
I stopped to do photography now due to weather and some situations, but i hope by Sept or Nov i start to shoot film again, and i am going to buy a developer maybe next month to be ready, i feel i will not process any sheet until i have many shots i've taken with sheets, will not waste my time to process 2-3 sheets per month-45days.