Edge density. Is this common problem?

[jvuokko]

Hi,

I have had a lot of problems with uneven development over years, solving most of them by going to tray development and occasional slosher like development.

However, one thing bugs me. The edge density is always too high.

I haven't found any cure for this. When developing on tray, it does not matter whether films are emulsion down or up.
Same with my 'slosher' which is actually Paterson Orbital daylight tank that I keep on the water bath and agitate two 'cycles' every minute.

Actually, this edge density problem was the reason that throw me from motorized Paterson Orbital to dip'n'dunk, tank processing with inversion, rotary processing etc.. Which all gave much worse results.
Eventually I settled to old tray development..

As I seem always get more density on the edges than center of the negative, I have been thought lately that perhaps this is quite common, or even normal situation.
However, I haven't seen much prints or scans that suffers from this problem.
Ofcourse, the real print that I have seen are printed by masters and never shown any trace of grown edge density.

So how to deal with this? Is there something that is wrong in all my developing methods, or is it just the thing that should live with and do some edge burning when printing negative?

I haven't never have change to see any other person's LF negatives, so I have nothing to compare against.


Example (I put the gray edges so edge density is more visible):
http://jukkavuokko.com/linkatut/lf/45_2011-04-13-3%20dark%20edges%20web.jpg


And another:
http://jukkavuokko.com/linkatut/lf/45_2011-05-19-2%20dark%20edges.jpg

[JamesFromSydney]

I wonder if it could be the film holder. I've seen similar from one of my grafmatics.

[Jon Shiu]

There is a tray developing technique called brush development that is supposed to provide very even development. Only one sheet at a time is processed though.

Jon

[bob carnie]

I do not tray process film for the reasons you are showing.
I have been using rotary, with Jobo Expert drums now for years.
Even with these systems I have found that putting the drum in your hands like you are holding a steering wheel of the car and do firm but not agressive rotation of the hands there is not only inversion but as well a twisting motion that within the first twenty seconds of deveolpment is critical.

For tray processing I can only guess that if you use much larger trays than the film , more chemistry you will keep the edges away from the edges of the tray that may be causing more turbulance, therefore more image density on the film , therefore more lighter edges on your prints, which by the way on neutral grey sky's or backgrounds are extremely difficult to print back to even density.

But this is only a idea on my part since I do not tray develop film, that may be worth trying if you continue with tray development. Having the film centered away from edges will IMO give better overall development. Chemistry is cheap, compared with paper redoes because of this problem.

[BetterSense]

What size trays do you use, and how much developer? Do you do a pre-wet?

Until you get the problem sorted you might want to avoid composing to the edges.

[Richard M. Coda]

What Bob said... I used to get them all the time in trays. Been using a Jobo since 1991 now.

[Rick Olson]

Hello jvuokko,

I get the same density edge on some of my 5 x 7 negatives. I process one negative at a time in a light-tight drum with hand agitation (over/under twice) four times a minute. I am thinking light reflecting off the edges of the film holder might be causing this. I have also not found a solution to fix the problem.

Rick

[Michael Clark]

Could also be light reflecting off the inside edges of the back of the camera where the film holder seats against. I have a 5x7 B&J field camera and get this some time, have to either crop or edge burn.

Mike

[Heespharm]

Could also be light reflecting off the inside edges of the back of the camera where the film holder seats against. I have a 5x7 B&J field camera and get this some time, have to either crop or edge burn.

Mike

Couldn't uthen paint the inside with matte black paint?

[Ken Lee]

How are these prints made ? Scanner ? Enlarger ?

Film holders and carriers can reflect light onto the film edge. I used to see this when I used Microtek film holders. Now I tape my film to the glass instead: no more edge problems.

[Michael Clark]

How are these prints made ? Scanner ? Enlarger ?

Film holders and carriers can reflect light onto the film edge. I used to see this when I used Microtek film holders. Now I tape my film to the glass instead: no more edge problems.
Had that happen with my omega's aluminum neg carriers, blacked the inside edges with a marks-a-lot marker which helped.

Mike

[Bruce Watson]

As Bob said, the cure for uneven development, and in particular edge problems, is the Jobo expert drums.

That said, I've seen a little of this from brand new film holders. The film hold down rail can be very shiny, and reflect light hitting it back onto the very edge of the film, such that the edge gets both direct light and light reflected off the hold down rail resulting in increased exposure. It typically only happens on the negative where it's getting lots of light anyway (like skies). The cure for this is a little fine grained sandpaper to take the surface of the hold down rail from shiny to matte.

[Mark Woods]

I was having the same problem, but only with 8x10. One of the members here suggested pre-soaking the film for 4 minutes. I did, and that solved the problem.

[Merg Ross]

I was having the same problem, but only with 8x10. One of the members here suggested pre-soaking the film for 4 minutes. I did, and that solved the problem.

Yes, my original thought to this problem was development procedure. What size film, what size tray, and do you pre-soak? The latter is essential. With the proper procedure, tray development should yield negatives devoid of this edge problem. Perhaps there are other factors that come into play here, but I have never had this problem with tray development. I did have such a problem with hangers and gave them up decades ago.

[jvuokko]

Back to old topic :)

I think that I am never fully satisfied with the evenness of the skies. Perhaps I am just chasing a ghosts?

Here's example. Fomapan 100. 4x5, developed in jobo expert 3010 using D-76 1+1.
Rotation was done on rollers by rotating tank manually as I don't have jobo processor and my motorised rotator doesn't work well under heavy 3010.


There's still a bit unevenness on the sky. However this is best result with 3010 so far.

http://farm4.staticflickr.com/3717/8842456241_79483798e8_o_d.jpg

[Jac@stafford.net]

The top of the film (as it would be in-camera) has little of the effect. I agree with others who suggest you check the camera for edge reflections.

[paulr]

What developer are you using? Some developers demand much more even flow to give even development. Generally a formula that encourages edge effects will be more challenging.

I used to use D-76 in a jobo (non-expert) drum, and always had a strip of increased density on the top and bottom edges. I eliminated the problem by reformulating my developer. Switching to the expert drums probably would have worked also.

[Jerry Bodine]

Had that happen with my omega's aluminum neg carriers, blacked the inside edges with a marks-a-lot marker which helped.

As soon as I bought my Omega enlarger, I took all my carriers (6x6, 4x5, 5x7) to a professional "plater" and had them anodized to make them flat black all over for durability. Expensive, yeah!!

[David Vickery]

The Tray is too small and you may also need more random agitation.

[Doremus Scudder]

There are a couple of different topics being discussed here that we should differentiate.

The first is increased density on the negative due to reflections from the filmholder edges or hold-down rails. I've had this happen and it's maddening. Sanding with fine sandpaper and a little flat-black spray paint usually solves the problem. However, I don't believe this is the OPs problem.

Another is a similar problem: that of reflections from negative holders when enlarging or scanning. The solution is similar to the above: identify and modify the reflective surface.

The third, and what I believe to be the OPs problem from looking at the examples posted, is increased density on the edges of the negative from developing. When tray developing, this is usually due to using too small of trays and/or pushing the film down into the developer to quickly, causing turbulence at the edges which gives the increased density. The solution to this is to refine your tray-developing technique. Use a tray one size larger than the film you are developing, use a pre-soak (I like a minimum of three minutes) and, most importantly, take real care when immersing and shuffling your negatives to not push them straight down into the developer quickly. Just plopping it down flat and then pushing down with the balls of your fingers will almost inevitably lead to increased edge density. I slide the negative in, letting one side lead just a bit, and gently guide it to the bottom of the tray. The negative should almost sink on its own. Anything you do that increases the flow of developer at the edges will have an adverse effect on evenness. Try to keep the developer flow even across the whole negative surface. This should help with the problem.

Hope this helps,

Doremus

[Jim Noel]

From Eddie:"For tray processing I can only guess that if you use much larger trays than the film , more chemistry you will keep the edges away from the edges of the tray that may be causing more turbulance, therefore more image density on the film , therefore more lighter edges on your prints, which by the way on neutral grey sky's or backgrounds are extremely difficult to print back to even density."

You are correct Eddie. Turbulence along the edges of the tray results in over-development along the edges of the film. I use an 11x14 tray for 5x7 film, and 16x20 for 8x10 in order to prevent this. for larger film, 7x17, i agitate by lifting and flipping the film so the turbulence does not occur. Only when i am inthe mood do I use the energy necessary to lift the Jobo into the sink. I really prefer tray development.

[fhovie]

Presoaking and Jobo reels do not produce this for me. You could try straight stand processing. The results can be really nice - slightly harder grain, range compensation and better accutance.

[Mark Woods]

I also realized that on my hangers, one side has many perforations, while the other side does not (I have some Kodak 8x10 hangers). Once I made sure the emulsion faced the side of the hanger with the perfs, the problem was solve. I still pre-soak.

[Drew Wiley]

Old-school thick-emulsion sheet films are a little more prone to excess edge density than thin emulsion films. I always use oversized dimple-bottom trays. The sheets
of film are not just shuffled but rotated so that each of the four sides of the film gets pulled sequentially and very gently.

[JW Dewdney]

I've never seen this before on large format film. Something is terribly wrong with your agitation- it LOOKS like perhaps you're agitating side-to-side somehow. I've never used the paterson system though so you'll have to find a good technique with those. If you want hassle free smooth perfectly developed film I'd recommend hangers... i've never used anything but those (apart from a few attempts at tray processing) and NEVER had a problem...

[ic-racer]

I got this with my first sheets of 8x10 processed in an 8x10 tray. I changed to rotary development with much improvement.

[ROL]

I got this with my first sheets of 8x10 processed in an 8x10 tray.

Which is one reason why I remind those who do tray processing to use at least one size larger tray (i.e., 8x10 –> 11x14) and not skimp on developer to avoid unevenness from developer drag in large mono-tonal areas.