Developing and scanning large format 4x5 - need help

[dalton]

I have been shooting MF for a while and have gotten quite comfortable with the

development process for that format. My transition into large format is having a

few bumps, however. I was wondering if anyone could offer some tips?

 

I am shooting Ilford FP4 @ EI 80 and developing in HC110 Dilution H. I am

developing in BTZS tubes, which is my first experience with continuous

agitation. In determining my development times, I took a time that worked for me

for FP4 medium format (8 minutes, gentle agitation) and reduced development by

20% to account for continuous agitation. So, I am developing for 6 1/2 minutes

at 68 degrees. My negatives are bulletproof and scan very poorly.

 

 

I realize that I need to experiment and back off the development times a bit,

but I was wondering if someone could give me some feedback on other aspects of

the process that are new to me, so I can understand it better.

 

My first question is scanning LF film. The negative base appears to be thicker

than 35 and MF film... is this generally true? Does this affect scanning? Even

the unexposed area around the image is a dull gray and not clear like other

formats I've used. Is this normal, or is there a chance that my film is fogged?

 

Second has to do with continuous agitation: it appears that the general

calculation of 20% less time than standard agitation is way off in my case. Am I

doing something wrong?

 

I know there are a series of tests to help establish proper exposure and

development time for a particular film. I am going to look around and give that

a try. Any pointers for this first time large format shooter would be extremely

appreciated.<div></div>

[dalton]

Wanted to add the histogram from my scanner, too, just to show how tough the scans are:<div></div>

[henry_a]

I'd use a different developer if you have it. Xtol or D76 diluted a bit to get longer times. I like at least 8 minutes and prefer longer.

 

If no other developers are available then dilute your HC110 even further. Or drop down to 5 minutes with one test sheet, that might get you there. But you'll have a hard time doing minus development when the normal time is that short. Be sure to keep enough stock solution per sheet in your tubes.

 

I'd test a sheet for possible fogging. Develop one sheet straight out of the box if you suspect you've fogged the whole box this is how to know for sure.

 

The unexposed film under the film holder guides should be as clear as from your roll film cameras edges. The sheet film base is a bit thicker but it is still clear.

[dalton]

<p><i>"I'd test a sheet for possible fogging. Develop one sheet straight out of the box if you suspect you've fogged the whole box this is how to know for sure.

<p>

The unexposed film under the film holder guides should be as clear as from your roll film cameras edges. The sheet film base is a bit thicker but it is still clear."</i>

<p>

Aha! I was very seriously starting to wonder about that. The unexposed film under the holder guides are most certainly not clear. I have never fogged film before nor seen an exposed 4x5, so I wasn't sure that it wasn't supposed to be that way. I think this might be the problem. Unfortunately it appears that way with the two sheets of HP5 I've developed as well as the 5 or 6 sheets of FP4, so I must have done something wrong, either exposed both boxes or maybe I'm screwing up during development, although I'm being very careful.

<p>

I'll develop an unexposed sheet of each tonight and see what comes out. If it's not clear, I'll pick up a new box and see if that's any better. Thanks so much for the help!

[jtk]

That's either a remarkably nasty scan or strangely-regular physical abrasion. Lots of horizontal banding and/or scratching (it moves when I move your image, so it's not the monitor).

 

It does seem to have a textural pattern in addition to the banding, so my bet is that you've got a very bad scanner.

[jtk]

...if you had trouble loading the tube that might be the source of the abrasion, but it looks more regular than I'd expect from handling.

[dalton]

<i>"That's either a remarkably nasty scan or strangely-regular physical abrasion. Lots of horizontal banding and/or scratching (it moves when I move your image, so it's not the monitor).

<p>

It does seem to have a textural pattern in addition to the banding, so my bet is that you've got a very bad scanner.

<p>

...if you had trouble loading the tube that might be the source of the abrasion, but it looks more regular than I'd expect from handling"</i>

<p>

Thanks John, <br />

The negative is not scratched and the scanner seems to be operating correctly. I scan medium format with this scanner regularly and get very impressive results. (here's a good recent <a href="http://www.seriouslyexcited.net/2007/09/07/brooklyn-exchange-church-at-clinton-and-kane-street/">example</a>)

<p>

The problem is most certainly that the negative itself is too dense for the scanner to read... note that the noise is much worse in the lighter colored areas, where the highlights have overdeveloped. The darker shadowed areas are much less dense and therefore look OK.<p>

 

Just trying to troubleshoot the density issue... I like the fog hypothesis because it is easy to verify and hopefully easy to troubleshoot. If anyone has experience with BTZS tubes and wants to give some hints about development time, that would be great too.

[wolfgang_am]

I have just played around with development on LF negatives recently and I found out that the same film behaves differently in LF than in 35mm.<p>

For testing (actual) film speed and/or developer this site is an excellent start: http://www.zonesystem.com/filmtests/ (a pitty not all links work here perfectly, but you will find all the information you need).<p>

I do my development in trays, but what I know from literature is that continuous agitation changes a lot. High dillutions for decreasing contrast don't work any more because the effect of using up developer locally is not given anymore. Staining developer might help here better.<p>

Your scanner seems to be ok. Even drum scanner perform badly with very dense negatives - and your histogram really looks like that.

So I would recommend to experiment with some sheets and find out a least an N development with a straight density line from 0.15 to 1.65 or so. Fog doesn't really harm here and can be subtracted from all densities.<p>

To get some 10 zone grayscale cut out some cardboard steps and use it as a guide for pulling out the dark slide. Each step you have to expose with a gray card (take a full format photo of it) according to the table below.<p>

The numbers depict exposure amounts:<p>

<table border="1">

<tbody>

<tr><td> <td colspan="10">zone

</tbody><tbody>

<th> <th>X<th>IX<th>VIII<th>VII<th>VI<th>V<th>IV<th>III<th>II<th>I

<tr><td>step<td colspan="10">light amount

<tr><td>1<td> 256

<tr><td>2<td> 128<td> 128

<tr><td>3<td> 64<td> 64<td> 64

<tr><td>4<td> 32<td> 32<td> 32<td> 32

<tr><td>5<td> 16<td> 16<td> 16<td> 16<td> 16

<tr><td>6<td> 8<td> 8<td> 8<td> 8<td> 8<td> 8

<tr><td>7<td> 4<td> 4<td> 4<td> 4<td> 4<td> 4<td> 4

<tr><td>8<td> 2<td> 2<td> 2<td> 2<td> 2<td> 2<td> 2<td> 2

<tr><td>9<td> 1<td> 1<td> 1<td> 1<td> 1<td> 1<td> 1<td> 1<td> 1

<tr><td>10<td> 1<td> 1<td> 1<td> 1<td> 1<td> 1<td> 1<td> 1<td> 1<td> 1

</tbody><tbody>

<th>Sum<th> 512<th> 256<th> 128<th> 64<th> 32<th> 16<th> 8<th> 4<th> 2<th> 1

</table>

<p>

For example you found out the correct exposure is some aperture (whatever) and some exposure time e.g. 1/15 sec.<p>

This aperture is the equivalent to number 16 (no not 8!) because the sum of zone V is 16. So you start your first exposure with light amount 256 which is an exposure time of 2 secs with one step of the dark slide pulled out. Pull out the next step and expose with 1 sec and so on. Always divide time by 2. You will reach 1/125 sec at the second last step. Be aware that you have to take this time in the last step also (not take half of it!).<p>

If you adjust aperture for exposure time 1/15 like in this example you will receive all shutter speeds for a normal LF shutter except 2 seconds. You can help by exposing twice 1 second.<p>

This will yield a beautiful grey wedge exposed from zone I to X which you can develop your style.<p>

If your scanner respectively its software supports raw format you can use it as densitometer. Read out the density values of the raw positive scan. The density is log10(255/value). You have to measure fog (of not exposed film) as well and subtract this from all values.

See the instructions from the link above to evaluate.<p>

<br>

PS: If someone needs fomapan data, send me a message.

[jtk]

Wolfgang, do you see the banding that I mentioned? I don't understand how a night sky could be so dense in a negative to cause banding.

 

Dalton, your MF sample doesn't have large-enough areas of even tone to display the problem that's obvious in your night sky. Day Vs night.

\

Somehow, I've not had much experience with overly-dense night skys :-)

 

*** What scanner produced this problem?

 

This has shown up previously on P.N, having to do with flatbeds.

[sg_adams]

A couple times I got newton rings using my Microtek flatbed, but never with B&W and using the neg holders.

Having just entered the realm of scanning film, it has become obvious that the dense negs I was used to printing aren't good for scanning. Whether medium or large format, I am having much better luck now exposing and developing for a less dense neg with regards to scanning. I have recently returned to FP4 and having much better results with that film, and I find it scans well. But I use periodic inversion for roll film, and dip and dunk for sheet film. D-76 1:1 has provided very agrreable results this go round,and provides for the longer development times suggested above. Something like a 25% pull makes this a necessity I think for proper development of the emulsion. Also try tray developing a couple sheets individually, and perhaps make a comparison to similarly exposed film done with your continuous agitation. My feeling is that the continuous is not a good idea with B&W films, but this is only MHO...

Stephen

[dalton]

John: Here are <a href="http://www.seriouslyexcited.net/tag/film">several more photos</a> scanned by the same scanner, and Epson 4990. I've been using the scanner for six months now with no problems, and just scanned another MF negative. I'm 99% sure the scanner is not the problem.

<p>

Stephen: I will give tray development a try as well and see if I have any more luck.

<p>

Thanks everyone for the help!

[dalton]

Wolfgang : thanks so much. A lot of incredibly useful information in that post.

[wolfgang_am]

<b>Dalton:</b> First of all thanks for your positive feedback!<p>

The banding in the scans come from the scanner. Streaks from continous rotation are not so evenly distributed but have more even transitions. Those stripes come from the sensor. They become worse with higher temperatures. They are like hot pixels in digital and as you have only one line of sensors, not an array, it comes like this. You see those effects mostly in extreme densities, like you have in your negative. <p>

By the way, did you try a farmers reducer? (see http://www.digitaltruth.com/techdata/farmersreducer.php and try the proportional one)

[dalton]

Ugh. I just developed a roll of HP5 120 medium format and discovered that it was fogged too. This is the first time this has happened to me in years of developing film. So, at least I know it's probably not the camera. And I used a completely different development process (BTZS tubes vs. Patterson daylight tank), so that would be a weird coincidence too.

 

Of course, I did just buy a new changing tent, which would be an obvious suspect if it weren't for the fact that the first two sheets of 4x5 I developed were done in my old changing bag and show the same characteristic of being exposed even in the area that is supposed to be protected by the holder. Now I've got a real mystery to solve.

 

Wolfgang, thank you for the suggestion of farmers reducer. I've never heard of it before and will investigate. Of course, I would love to get the density down to a manageable level with normal development technique, but I really do want to salvage some of these negatives I worked so hard on, so I might just give it a try.

[jtk]

Dalton, your 120 are beautiful images but those skys that show any tonality are ultra-grainy...are they 3200ei stuff? Might be a meter question as much as development question.

 

Right, unlikely to be agitation. I still wonder about physical abrasion, a common problem with tubes.

[dalton]

I just wanted to thank everyone who participated in this thread and helped identify the cause of the problem. Of course, it was complete operator error and nothing more. It turns out my fixer was exhausted.

 

Something I didn't immediately recognize when I started working with large format is that each sheet of film uses almost as much chemical as a roll of 35mm film. So instead of developing 10-12 rolls of film with one batch of fixer, I can now develop 10-12 negatives. Lesson learned, I am going to pick up a fixer test kit just to be safe from now on.

 

Now on to more questions about HC-110 and BTZS tubes... more on that in another thread!