My enlarger exposure times are way out of whack

[Rob H]

I've been away from analog photo stuff for a while, but recently came back and have been making some prints. I read on forums what typical exposure times are for enlargers, and seeing numbers like 20 seconds, but this is not how it has been for me. My exposure times are rarely more than 6 seconds with what I consider to be very straightforward prints.

Below is a pretty standard print. The negative has good contrast. The aperture on the enlarger is set at f11, and the lens is 10" above the board. The contrast filter is a #3. This is a 5x7" print, and the exposure time is 3 seconds.

I develop all of my prints in Dektol for 1:40.

I'm having to stop down to very low apertures, which causes diffraction issues in my prints.

I don't remember having this problem before. I'm considering seeing if I can get a lower wattage bulb, because the exposures are so dang fast. Other than that, besides reducing development time, I can't see how I can increase the exposure times to long enough where I can do things like dodging and burning.

There's another issue in this photo you can comment on if you know the cause: You can see a faint, light line going through the middle of the tree that is not in the negative. I've seen this on other prints I've made too, but not all of them. To expose the print I slide the lower filter out, which holds a red safety filter. I'm wondering if that's related.

Thanks in advance!

 

[koraks]

Welcome to Photrio, @Rob H !

Don't attribute too much weight to the exposure times other people have mentioned online. They might be longer than what you're getting for a variety of reasons. One major reason is the difference between papers, with some (most) warm tone papers in my experience being considerably slower than neutral tone papers. For instance, the difference between Fomabrom (neutral) and Fomatone (warm) is in my experience some 2-3 stops.

That's just one factor; there are several that will influence exposure times.

The 6 seconds at f/11 for a 5x7" print sounds very reasonable to me. If you find that inconvenient, consider using an ND filter or, as you mentioned, see if you can get a weaker bulb. An ND filter gives you more flexibility, though.

You can see a faint, light line going through the middle of the tree that is not in the negative.

Yes, I can see it. There's a couple more conspicuous shorter diagonal lines of an apparently similar nature in the right set of fronds on the tree. I'd start by inspecting the optical path to exclude the possibility you've got anything in there...cobwebs or cat hairs come to mind! It's a bit of a wild guess though; several possible causes might play a role here and I'm sure some other people will also chime in on this.

In any case, welcome aboard and I'm sure there will be some useful responses to your questions

 

[Rob H]

Thanks Koraks,

The line that extends from the main line in the tree is not in the negative either. The other lines appear to be just in the clouds.

I almost wonder if I have some little reflective bit in the filter slide (below negative) that somehow does something... it's weird. I saw it once before on a previous negative, but it disappeared, only to reappear here.

 

[koraks]

some little reflective bit in the filter slide

It would create a dark band, not a light one When paper fogs, it builds density, so stray light will result in higher densities instead of lower ones.

You either have something blocking the light path, an anomaly in the paper or processing (unlikely with this pattern) or an anomaly in the negative that you've simply overlooked (yet).

I saw it once before on a previous negative, but it disappeared, only to reappear here.

If it's the exact same shape in the same spot, but on a different negative, it's nearly certainly enlarger-related. Again, look for fouling.

 

[faberryman]

One suggestion is to use a longer focal length enlarging lens so that you have a greater distance between the lens and the paper for the same size print. Perhaps an 75/80mm or even a 100/105mm. In addition to giving you longer exposures, it will give you room to dodge and burn.

 

[Rob H]

Are all enlarger lenses compatible? Do they use a common mount size? I found several enlarger lenses for really cheap, but don't know if there are any compatibility issues.

 

[koraks]

One suggestion is to use a longer focal length enlarging lens so that you have a greater distance between the lens and the paper for the same size print.

But this won't bring light levels down. The only 'advantage' would be that longer lenses tend to have have an additional one or two smaller aperture settings that a shorter lens doesn't have. That would still land OP deep into diffraction territory.

Are all enlarger lenses compatible? Do they use a common mount size?

Most enlarger lenses and lens boards use an M39 screw thread. There are exceptions though. In those cases, custom lens boards or adapter plates can be a solution.

 

[ic-racer]

Would need to know the specificaitons of the enlarger and lens you are using to answer your questions.

 

[ic-racer]

One suggestion is to use a longer focal length enlarging lens so that you have a greater distance between the lens and the paper for the same size print. Perhaps an 75/80mm or even a 100/105mm. In addition to giving you longer exposures, it will give you room to dodge and burn.

 

[faberryman]

It seemed like a good idea at the time, the time being 3:00am.

 

[xkaes]

Would need to know the specificaitons of the enlarger and lens you are using to answer your questions.

What a concept. Before jumping into the pool, at a minimum, make sure it's full of water.

 

[Rob H]

Would need to know the specificaitons of the enlarger and lens you are using to answer your questions.

Ah yes, sorry. It's a Beseler 23c.

 

[ic-racer]

Ah yes, sorry. It's a Beseler 23c.

There were quite a few versions of that, a picture is worth a thousand words!

Most importantly, is this a condenser or diffusion light source on top?

If condenser, the white line in the photograph may be on the dome of the lamp and the light output can be diminished with ND filter set on the top condenser, and/ or a lower wattage lamp.
If diffusion, the white line may be on the diffusion plastic and the light output could be diminished with the color head settings, equal Y and M.

Lens compatibility with your enlarger will depend on the type of lens mounting currently in place. Simple hole with a retaining ring on the back of the lens threads, vs a threaded lens board.

 

[ic-racer]

It seemed like a good idea at the time, the time being 3:00am.

Indeed at the same absolute aperture size in millimeters, the longer lens will pass less light (because the f-number is smaller). However, the effects of diffraction with the longer lens are magnified, so in the end, nothing is gained.

 

[Rob H]

H read elsewhere that they make ND filters for the filter drawer. I suppose I could put one in there, plus the contrast filter?

 

[Ian C]

If you want to use an enlarging lens at its optimum aperture to make small prints with longer exposure times that allow you to do manipulations, such as burning & dodging, exposing selected areas at different contrast grades, and so forth, the easiest option is to install a neutral density filter on the lens.

Neutral density filters are commonly available in the following densities:

ND 0.3 = 1 stop = 2X time factor

ND 0.6 = 2 stops = 4X time factor

ND 0.9 = 3 stops = 8X time factor

ND 1.2 = 4 stops = 16X time factor

Other densities are available.

Most, but not all, enlarging lenses have female thread at the front that allows mounting filters, thread-in filter holders, etc. For example, my 50 mm f/2.8N El Nikkor has 40.5 mm x 0.5 female thread at the front of the barrel. I bought a cheap step-up ring of that size that steps up to 52 mm x 0.75 female thread at the front. This allows me to mount any of my 52 mm Nikon filters on the lens.

Here’s the step-up ring I use with my 50/2.8 El Nikkor. It’s cheap and fits properly.

https://www.bhphotovideo.com/c/product/809750-REG/Sensei_sur40_552_40_5_52mm_Step_Up_Ring.html

50 mm enlarging lenses are equipped with various front thread sizes. Some common sizes are 40.5 mm x 0.5 mm, 43 mm x 0.75 mm. My 50 mm f/4 El Nikkor has 34.5 mm x 0.5 mm front thread.

An ND 1.2 = 4 stop = time factor 16X filter allows making the print (based on the exposure cited in post #1) at 12 seconds at f/5.6. Using this filter on the lens at various aperture settings between f/5.6 and f/8 will give exposure times from 12 seconds to 24 seconds without any noticeable diffraction effects. That should give you sufficient time to manipulate the print to your liking.

Regarding the odd lines on the print, on a Bessler 23C with the condenser and opal photo lamp, you should check that the interior of the lamp chamber is clean. It should be solid white. Sometimes old lamp heads get fouled inside by spider webs or fungus. Likewise, check that the condensers are clean as well. They’re fairly easy to remove and clean. Also, check the filter slots. If you have a heat-absorbing or other filter installed, it might have become contaminated.

It will be useful to state specifically whether the enlarger is equipped with the simple condenser and lamp head or with a dichroic color head. If the dichroic head is in use, is it used with the condenser unit, or do you have the diffusion unit installed instead?

Are you using a glass negative carrier? If so, examine it carefully for scratches or other marks on the glass. Since the glass is so close to the negative, any marks or scratches will get projected noticeably onto the image.

 

[Nicholas Lindan]

H read elsewhere that they make ND filters for the filter drawer. I suppose I could put one in there, plus the contrast filter?

Available in various densities, cut to size, goes in the filter drawer:

https://www.bhphotovideo.com/c/product/163141-REG/Rosco_102302102124_E_Colour_210_6_Neutral.html

 

[Sirius Glass]

Does your enlarger have a choice of brightness? Some do.

Welcome to APUG Photrio!!​

 

[mshchem]

Looking at the print. Appears that the paper is slightly fogged. Comparing the print border to the white wall. Maybe check safelights and paper.

 

[chuckroast]

I've been away from analog photo stuff for a while, but recently came back and have been making some prints. I read on forums what typical exposure times are for enlargers, and seeing numbers like 20 seconds, but this is not how it has been for me. My exposure times are rarely more than 6 seconds with what I consider to be very straightforward prints.

Below is a pretty standard print. The negative has good contrast. The aperture on the enlarger is set at f11, and the lens is 10" above the board. The contrast filter is a #3. This is a 5x7" print, and the exposure time is 3 seconds.

I develop all of my prints in Dektol for 1:40.

I'm having to stop down to very low apertures, which causes diffraction issues in my prints.

I don't remember having this problem before. I'm considering seeing if I can get a lower wattage bulb, because the exposures are so dang fast. Other than that, besides reducing development time, I can't see how I can increase the exposure times to long enough where I can do things like dodging and burning.

There's another issue in this photo you can comment on if you know the cause: You can see a faint, light line going through the middle of the tree that is not in the negative. I've seen this on other prints I've made too, but not all of them. To expose the print I slide the lower filter out, which holds a red safety filter. I'm wondering if that's related.

Thanks in advance!

View attachment 342731

• There is no standard exposure time for negatives. It varies greatly with negative density, light source, distance from easel, and developing technique.
  
  
• The 23C enlarger was shipped with a condenser lamp housing (I used to own one - great enlarger). This tends to be quite bright.
  
  
• Check to make sure you have the proper wattage bulb in the enlarger and that it is a bulb made for enlargers. The line you see might be attributed to a "normal" bulb filament shadow showing up on the image.
  
  
• Make sure you have the condensers setup correctly for your film size.
  
  
• There is nothing magic about enlarger focal lengths so long as they cover the negative completely. Longer length lenses can be used on smaller than usual negatives. For example, I routinely use a 60mm or 80mm lens with a 35mm negative (to get the enlarger up a bit which reduces light and lets me work in the middle of the aperture range). I often use a 150mm lens (intended for 4x5) on 6x9 negatives.
  
  
• There is some variation in enlarger threads, the most common being nominally 25mm, 32mm, 35mm, and 39mm Leica thread mount. The only thing they must have in common is that they all use the same lens boards made for your enlarger, drilled for your particular lens mount diameter, of course. On some older enlargers, you need a board that has an extension cone on it to use longer focal length lenses, but that shouldn't be an issue with the 23C.
  
  
• If you do buy more lenses, make sure they are clean, don't have oil, haze, or fungus in them. I'd stick with the top of line lenses like Schneider Componon, Nikon El-Nikkor, and Rodenstock Rodagon. They're reasonably priced used on eBay,
  
  
  Fun Historical Fact: It's possible - and used to be quite common - to use camera taking lenses as enlarging lenses. Our forefathers would take their very sharp lenses off their view cameras and mount them on the enlarger to project the image for printing. In some cases, they even used the view camera itself as an enlarger.

 

[L Gebhardt]

How thin is your negative? It looks like it could be underexposed based on the relatively low details visible in the tree. That will make your exposures short.

It looks like you have several lines on the print, but the lighting is so uneven it's hard to tell. Try making a contact print with the same grade 3 filter and see if they still show up to rule out any issues with the enlarger.

1:40 is short for fiber development times. That could lead to uneven development if you are using fiber paper.

You mention sliding the filter out to start the exposure. I wouldn't do it that way. If you have a timer use it. If you don't I would use a large sheet of cardboard held below the lens that you can quickly remove without touching the enlarger while the light is on. You should also test the red filter. I don't trust them to have not faded and to not leak light. If they create scattered reflections as you remove it that could create print artifacts with your really short exposures. Most likely you could get a foot switch to turn the bulb on and off, but that will be dependent on your enlarger details. It would also free your hands for dodging.

 

[MattKing]

Welcome to Photrio!

 

[Melvin J Bramley]

Rectify the fogged paper issue and try again..

TB

 

[Rob H]

I've ordered a dimmer switch as a first option, assuming that bulb is dimmable. That will save me a lot of trial and error with different bulbs.

 

[MattKing]

I've ordered a dimmer switch as a first option, assuming that bulb is dimmable. That will save me a lot of trial and error with different bulbs.

That may change the colour temperature of the bulb, which in turn may change the contrast response of variable contrast papers.