Jobos Web Site And Streaking On 4x5 Negs

[albert_martinez]

Out of the six negatives processed, one of them had a very faint

streak running down the middle of it. An instructor at the photography center mentioned a clip or gadget of some sort that

needs to be added to the Jobo six sheet container so this doesn't occur. Has anyone ever heard of such a clip or gadget that would prevent this from happening. I've never noticed it before so I

find it very strange we need one now.

Would appreciate any thoughts.......

Also, does anyone have Jobo web site, a search on yahoo

doesn't come up with anything.

 

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Thanks,

Albert

[sal_santamaura]

http://www.jobo-usa.com

[pemongillo]

I don't know about a "clip", but there are two plastic devices that

snap onto the reel. I don't think these would have anything to do

with streaking, they just keep the film in the reel. I did get some

streaking when I first got my Jobo, but I quickly determined that I

was not turning the drum on the hand roller smoothly. I would spin it

by the cap with one had. This gave a jerky agitation. I now roll

smoothly with two hands. I count 20 revolutions one way and the go 20

the other until the time is completed. I have not had a streaking

problem for almost two years know. You may also want to start with no

more than four sheets of film per batch until you are confident with

your film loading.

[albert_martinez]

I just found the "clip" on the Jobo site.

Apparently there's a black guide of sorts that keep the edge

of the film from touching the adjacent sheet. I know for a fact it's

not on the carrier I'm currently using, hopefully this will do the

trick-thanks for the responses and your help.

Albert

[pemongillo]

Albert, you have gotten my curiosity up. Are you talking about the

film guide? This is used to help guide the sheets onto the reel.

This does not go into the tank during development and won't insure a

streak free process. This just makes it easier to load the film. I

don't use it , because with a little practice the film goes on

smoothly. Its just one more thing to lose in the dark. If this is not

what you are talking about, please guide me to the place where you

found this on the Jobo sight. I saw nothing new in the 2500 series

section of the website.

[john_hicks]

The earlier Jobo 2509 reel had no clips; it was suggested that only four sheets be loaded, rather than six, so they wouldn't bulge and touch.

 

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The newer 2509N <--note the N has two snap-on plastic clips that serve to lock the sheets into place so they don't bulge and also disrupt any laminar flow of solutions to avoid streaks.

 

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I don't know how you'd tell whether you have a 2509 or 2509N other than that the 2509 would't have the two small nubs on opposite inner ends of the reel that the clip would snap onto. The only marking on my 2509N is 04068 molded into the clear-plastic reel end.

 

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So the Jobo website at http://www.jobo-usa.com/products/2500.htm for more info.

[pete_andrews]

Despite there being six slots in the 2509 holders, Jobo's instructions

at one time insisted that only four sheets could be processed in these

things if there was to be sufficient flow space.<br>I've got two of

these reels sitting redundant, since I was never able to resolve the

pouring time problem, with its inevitable 'tide line'. Other problems

I encountered included streaking and foaming marks.

[john_henderson1]

Be sure that the tank, lids, tops and reels are all very dry before

loading. The streak may be some residual water that rolled across the

film before processing began. Also, be sure to pour the chemicals in

very quickly and begin agitation as quickly as possible.

[hagai_kaufman]

I use these tans a little differently than what Jobo says: I fill the

tank all the way to the to with 1350ml of solution and agitate by

turning the tank upside down like I do with the steel tanks I use for

smaller formats. I insert the reel with 6 sheets and the

black "wings" in the tank with the developer in the dark, then close

the lid and agitate for a minute, then 10 sec every minute. This

works fine with no spots or marks on the sheets. I use pyrocat HD and

Rodinal, two very cheap developers so I don't mind the extra volume.

I don't know what the 'experts' will say about this method, but I got

my negatives to porve me right. Hope this helps, and good luck.