Jobo expert 4x5 w/ unicolor uniroller?

[will_stedman]

<p>I was wondering if anybody has used a Jobo expert drum for 4x5 sheet film developing with a motorized uniroller (unicolor) or if I should just use the 2509N reel. I read a thread somewhere where it was mentioned that the expert drum must be used at top speed on a developer, so I just wanted to make sure that the uniroller speed is adequate for even developing. Thanks in advance for any input.<br>

Will</p>

[david_zheng1]

<p>I never used Unicolor, but I use expert (3010) on Jobo cpp2 that I found low speed was good enough. I usually set up lowest speed when I used expert drum.</p>

[steven nelson]

<p>I have successfully used the Jobo Expert drum with a motorized uniroller for many years with XTOL developer. I had previously used the 2509N reel but had problems with uneven development. </p>

[will_stedman]

Thanks Steven, that's exactly the feedback I was looking for. I guess now I should just save my money, although I

might get lucky on Ebay. Thanks.

 

Will

[georges_giralt]

<p>Hello Will,<br>

I own both, an expert drum and an Unicolor motor base.<br>

You'll face a couple of problems :<br>

First the Unicolor base has a timer inside it in order to switch the rotation. You've to change this timer in order for the Expert drum to make at least a full turn on the base. As it is a mechanical timer, you've to change it by putting in the box an electronic timer and adjusting the time to get a little more than one turn.This is because the Expert durm has a large diameter and is way larger than the original Unicolor drum...<br>

Next, the expert drum. This drum has opening in the back in order to fill with the jacket water in order to keep the developer temperature even. You will of course defeat this when using the expert drum on an uniroller base... This may be a more important problem that you may think. The Expert drum has been designed for this exact bath tempering and you may have difficulties keeping the chemical warm as it will be in contact with a large amount of untempered plastic... One other advice, the expert drum will fall of the uniroller base dring rotation, as the rotation will move it one way or another (depending of the wear of the rollers) and you'd better use a couple of thick rubber bands to keep the drum centered on the roller base.<br>

All this being said, I tell you you'd better buy a plain set of rollers from Jobo (P/N is 1506 ) which are a couple of roller support used in the Jobo processor linked with a couple of plastic rods. With this in hand, use a large basin, put into it water at correct temperature, the rollers at the bottom, and start rolling your expert drum into it. As the drum will fill with water it won't float, and it will be easy to run ot the rollers. The chemicals are spread into the drum and will be randomly touching the negs avoiding streaks ... So perfect dev anytime...</p>

<p>Hope this helps !<br>

P.S. The 1506 roller base is quite the same price than a 555 timer complete assembled and wired into the base. so there is not a cost related issue...</p>

[will_stedman]

Thanks Georges for the info. I had no idea about the added time for rotation on the expert drum. I actually just

ordered the Jobo 2509 for my 2500 tank. It's on backorder from Calumet. I figured out that I just don't have the

money for a new or used expert drum. Also, I read other threads and there seems to be mixed reviews about the

2509 reel. It seems that it works iust fine for some people. So I'm going to take my chances.

 

Cheers

 

Will

[rodeo_joe1]

<p>Not sure if you're aware Will, but it's advisable to use a pre-bath with the 2509/2500 combo. Otherwise you'll get the uneven development that Steven mentions.</p>

<p>I use a 2520 tank and 2509N reel with a Jobo rotary processor. When I first used this setup I suffered a variety of tide and foaming marks and nearly chucked the lot out. Then I read on Photo-net that a pre-bath was needed, and that cured the problem entirely. Plain water brought up to temperature will do fine, and there's no need to alter the developing time.</p>

[will_stedman]

<p>Thanks Joe. How long do you recommend for the pre-bath? <br>

Can I also ask you, even though it's completely off the subject, what your favorite film/developer is for 4x5? This is my first venture in to LF, having shot medium format with my favorite film, PanF, and Perceptol. Unfortunately, Ilford doesn't make PanF for sheet film and the delta 100 I've tried with perceptol and ID-LL just doesn't look right. </p>

<p>Will</p>