Reducing Enlarging Flare
One of the things you will learn if you attend one of John Wimberley’s printing workshops is the importance of reducing enlarging flare. Enlarging flare is non-image-forming light that reaches the enlarging paper. Enlarging paper reflects a large percentage of the light that falls on it. This means that light from the enlarging lens travels to the enlarging paper and then scatters into the immediate environment and needs to be absorbed, otherwise it will return the the enlarging paper as non-image forming light, aka enlarging flare.
A number of things can reflect light back onto the enlarging paper, causing enlarging flare:
In addition, several other components inside the enlarger can contribute to enlarging flare:
- Light that reflects off surfaces or components of the enlarger
- Light that reflects off the darkroom workers’ body or clothing
- Light that reflects off the walls or ceiling of the darkroom, furniture in the darkroom, or equipment in the darkroom
- Light that reflects from the surfaces of the paper easel
- Light that reflects from burning or dodging tools or the darkroom workers’ hands
- Light that is scattered by an unclean or damaged enlarging lens
- Light that bounces around inside the enlarger bellows
- Light that reflects from the glass of a glass negative carrier, forming faint ghost images
Enlarging flare has the ability to subtly fog the lighter tones of the print, reducing the brilliance of those tones. There are several ways to reduce enlarging flare, including wearing black clothing while making prints, wearing black gloves while dodging and burning, using multicoated glass in glass negative carriers (you can obtain multicoated glass for this purpose at Glennview), keeping the enlarging lens very clean, and blackening the surfaces that could reflect light that comes from the enlarging lens or is reflected from the enlarging paper. This last item is the subject of this article.
I recently obtained a Beseler 45V-XL enlarger and even though it is painted flat black , I needed to further blacken it to reduce enlarging flare. Most flat black paint is quite reflective and so I have used black flocking paper to line many of the reflective surfaces of this enlarger. First, let’s take a look at what the enlarging paper in the easel “sees.” The following photograph was made with a small digital camera that has a 24mm-equivalent (35mm terms) lens. I placed it on the enlarging easel, facing up towards the lens of the enlarger. As might be obvious, I used the flash on the camera to give a very vigorous exposure to all of the images in this article so that detail may be more easily seen.
The enlarging paper in the easel probably “sees” a lot more than the photo above depicts, but this picture is suggestive of the surfaces that could directly reflect light back to the enlarging paper.
A word about flocking paper. This material is a black, velvety substance on a durable paper backing, and it is great at soaking up light with almost no reflection. Most sources that sell flocking paper sell two varieties: adhesive backed and non-adhesive backed. For most darkroom use, I recommend the adhesive backed variety because it avoids the messy and smelly step of using spray adhesive.
I have experience with two sources for flocking paper: Edmund Optics and Protostar. In my experience, the Protostar flocking paper is less reflective than the Edmund Optics product. My Pentax digital spot meter measures 1 1/3 stop less light being reflected from the Protostar product. It is quite possible that this difference is the result of a batch-to-batch variation, and not an inherent superiority of the Protostar material. Both products are otherwise fine, but I now prefer the Protostar material. Additionally, the Protostar material comes in a roll that is easier to store and cut to precisely the needed size:
In the photo below, you can see that I have applied flocking paper to many of the enlarger’s surfaces (although I still need to cover the enlarger exhaust vent with black velvet). Also in this picture, notice the flocking paper that is applied to the horizontal surfaces of the enlarger and compare it to the flocking paper on the vertical surfaces (the foamboard piece on the right side of the picture and the enlarger column shield seen at the bottom center of the picture). The flocking paper on the horizontal surfaces of the enlarger is the Protostar material and the other flocking paper is the Edmund Optics material. To me the Protostar material, at least from the batch that I have, is noticeable darker:
One of the problems that had to be solved in this case is lowering the reflectivity of the enlarger column. I could have approached this in several ways including adhering flocking paper directly to the column, but I decided instead to create a moving flocking paper shield in front of the column. This shield functions like blinds for a window and it allows me to view the numbers on the enlarger support column by peeking behind the flocking paper shield. The pictures below illustrate how this was done:
I used a 3/4″ diameter dowel to hold the spare flocking paper. The amount of flocking paper needed to shield the column varies based on how high the enlarger head is and so the unused flocking paper is rolled on to this rod.
I used 1.5″ brass angle brackets, with woodscrews inside a nylon sleeve to support the rod while allowing it to rotate freely.
I used a string-pulley-weight system to keep a small amount of tension on the rod. This causes the rod to wind up any excess flocking paper when the enlarger head is lowered. Contrarywise, the rod spools out paper as the enlarger head is raised.
Here’s the completed system. It works very well so far!
In addition to these visible flocking treatments, I added flocking paper to the following places:
- The bottom of the negative carrier
- Surfaces inside the chamber between the negative carrier and the lens board
- The top surface of the lensboard
I think I’ve invested about 6 or 8 hours of work applying the flocking paper and building the mechanism that supports the movable column shield. Here’s the complete enlarging station (the black stuff behind and above it is a length of cotton velvet cloth):
As is so often and verily said, a chain is only as good as its weakest link. With these flocking paper treatments in place, I’ve removed one more weak link from my photographic imaging chain! I hope this information is helpful.
PS- If you ever have an opportunity to attend one of John Wimberley’s workshops, do it! He is a wealth of knowledge about all aspects of fine photography, a gentle sensitive guide, and a real master of the craft.
Neat ideas! I have a few questions, though: the velvety flocking paper, doesn't that introduce a lot of dust which may be hard to get rid of, compared to a painted which you can dust off easily? And can you see any differences in the prints you make now, and those made before making these adjustments?
“Do your work, then step back. The only path to serenity.” - Lao Tzu
Thanks for your questions Jerevan!
I have not noticed any extra dust introduced by the flocking paper. The flocking paper is quite clean as it comes from the manufacturer. If it becomes dusty during installation on the enlarger, then it tends to trap and hold on to that dust. A so-called "lint roller" would be the most effective way to remove trapped dust. And finally, if the flocking paper becomes dusty after being installed on the enlarger, then you have a separate problem of dust entering the darkroom, and that is unrelated to the flocking paper itself, although as you have pointed out it will be more difficult to remove dust from the flocking paper compared to a painted surface. I have sealed off the forced-air heating vent in my darkroom in order to reduce one of the main sources of dust in a home darkroom.
Installing the flocking paper in my darkroom was a part of a group of changes that I made all at once, as a result of my participation in a John Wimberley printing workshop. Yes, my prints are much better after making these changes, but I also changed paper, print developer, stopped underdeveloping my prints and over-taxing my chemistry capacity, started controlling print time for developer temperature, upgraded my negative carrier to multicoated glass, began aligning my enlarger (every time I load a new negative in the carrier), switched to a dichroic head, and made the flocking changes discussed in this article.
So obviously, this is far too many changed variables to allow me to say with certainty that the flocking paper improves my prints. John Wimberley's prints, to me, are as close to perfection as I've seen. I think that part of that perfection comes from his attempts to optimize every part of the image quality chain. The idea to use flocking paper to reduce enlarging flare is his, and I believe it makes a positive difference in print quality, but I can't prove it.
Hmmm, quite interesting.
Looks like you are using an external suck system for enlarger head cooling to reduce vibration caused by the on-board fan, has that made a difference as well?
You mention that you align the enlarger every time you change negatives, I'm not really sure what you mean by this. Alignment to me means using either a specially prepared negative, usually one with lines scratched across a black negative, or using a specialist alignment tool. Would you care to elaborate?
Nice to see someone taking the time and effort to reduce and/or eliminate, darkroom errors.
I'm an obsessive-compulsive, but I would never dream of aligning an enlarger for each new negative.
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I can't combat an enemy I can't see. I have been wanting to test for this and was thinking putting a flashed piece of paper right by the easel border with a quarter on it. I wonder if John gives any good ways to test for this.
Interesting questions all!
I am using an external cooling system for the enlarger head (http://www.apug.org/forums/forum216/...roic-head.html). I purchased the head used, and when it came to me one of the foam vibration-damping mounts for the internal cooling fan was broken. So when I turned on the fan, I could feel the head vibrating when I placed a finger one of the extremities of the enlarger head. I do not know how much of this vibration was due to the fan and how much was due to the broken fan mount. So I just dealt with it by building my own cooling system. I would suggest that any vibration that your finger could feel or any vibration that would disturb a glass of water resting on the head is enough to effect print sharpness, but you'd need to test your own equipment. Can you make a print with the fan turned on and the same print with the fan turned off?
I use a laser alignment system to align my enlarger, and because I use a glass negative carrier, the laser reflects from the negative carrier without any special attachments. My procedure is to load the negative carrier, remove the lensboard, align the easel to the negative carrier (I use a homemade version of the Ease-align system to adjust the easel rather than adjusting the negative carrier), then replace the lensboard and align the lensboard to the easel (by securing a small mirror to the lens threads and bouncing the laser beam from that and adjusting the Bes-Align adjustable lensboard). With this system, every time I load a new negative into the negative carrier I can check and adjust the system alignment. It takes 2 or 3 extra minutes each time and is worth it as far as I'm concerned. Especially because I find that the system is often out of alignment after removing the negative carrier, reloading it, and replacing it in the enlarger.
In his printing workshop John Wimberley recommends the following test for enlarging flare: Expose a whole sheet of paper to a Zone V density (test to determine what exposure this is). Leave the paper in the easel and hold a dodging card about 12" above the paper so that it will cover half of the paper when the enlarger light is turned back on. Place a small opaque object like a coin on the shaded half of the paper. Expose the paper, with the opaque object in place and half of the paper shielded by your dodging card, to light from the enlarger for four times your normal print exposure time. Process the paper normally. If you can see where the opaque object was, then you have enlarging flare. ic-racer, I think your test might also be valid. Flashing the paper to Zone V puts it on the steepest part of its HD curve before you do your enlarging flare test, and thus makes it the most sensitive to additional scattered light. Using a multiple of four times your normal exposure tests under worse case conditions like a negative that needs lots of burning, etc.
Last edited by felipemorgan; 02-14-2009 at 01:54 PM. Click to view previous post history.
Jaysus! after reading that i feel like I should only do my enlarging in "clean rooms" from the electronics industry -- crying now...... because in a clean room I'll look silly in those pull on plastic hats that stop dust from my remaining hair.... where does it end? ..... Epitah on Grave ... "here lies Simplicius. Crap Photographer but may he find the dust free darkroom that obsessed him to death in heaven"
wanders of leaving his intended humour behind
Do you have any before and after prints showing the improvements you expected? Before going to these lengths I think I'd need some evidence!
I don't have any before/after prints. I didn't think 6 to 8 hours was much time to invest towards improving my prints, so I just made the changes with the trust that there would be an improvement.