Not enough exposure time

[TroyG]

Hello, all.
I just got the final pieces for my darkroom today! So I've started about running tests, the first one is to find my SCT. I'm finding that I'm struggling to get gray tones. Here's my details:

Beseler 45M enlarger w/75 watt lamp
Schneider-Kreuznach 135mm lens
Ilford multigrade FB classic glossy paper
I put a 4x5 FB+F negative in the negative stage and the grade 2 filter

My first attempt to print I did three second brackets at f8. So I had exposure times of 3-30 seconds. The entire strip was completely black.

My second attempt I did the same but at f22 and I got two gray tones (so 3 seconds and 6 seconds) with the rest of the strip bring black.

The enlarger head is sitting where it does for enlarging a 4x5 negative to 8x10.

My question is why I'm having to cut down so much light to get usable exposure times? Feels like the lamp is too hot or the lens is too close. But 75w seems appropriate and the head being halfway up the height of the stand seems appropriate also. Can anyone think of what I'm missing?

Any direction would be lovely, I can't figure out what I'm doing wrong.

[Jac@stafford.net]

Try developing a paper with no enlarger exposure. Let us know the results.
.

[Pere Casals]

As you (I guess) saw a non suspicious projected image... only 3 things can go wrong:


> Developer

> Paper

> Safety light


IMHO the enlarger exposurse you made (f/22, 3 seconds) should not built density with development, guessing enlargement size was something common.

I'd do that:

1) Take a not exposed strip of paper, develop it without exposing it. Develop 2min does it go black ??

2) Repeat development of a new unexposed paper strip (2 min) in total darkness. If now result is white then it was safety/ambient light. It if not it is paper or developer.

3) Mix new developer to the right concentration, better is it is from a new purchase, try again.

4) Buy a new paper box.

[Rick A]

Test your safe light.
https://www.kodak.com/KodakGCG/uploadedfiles/motion/US_plugins_acrobat_en_motion_products_filter_K4_Safelight_1106.pdf

[TroyG]

I tested to see if it was my safelight earlier. I let a piece of paper sit exposed to the safelight for a few minutes and developed it. Pearly white!

That tells me it's not my safelight or paper. I made a print successfully but it was 15 seconds at f32.

The blacks seems fine so I don't think it's fogging. Im using ilford multigrade developer diluted 1+9.

[Winger]

Are you positive the lens is at f22, etc..? A couple of mine have levers on the back to open them up completely for focusing even when set for f16, f22, etc.. I've left them opened up a couple of times by accident.

Other than that, your methods and settings seem fine to me.

[TroyG]

This lens has no such release for the aperture, but I did check just in case! Though it's very precievibly darker at f32 than it is at f4.5. My question I guess would be, how dark should it be? My only logical conclusion is that my lamp is too bright. But I inspected it and it says it's only 75 watts. With the lens stopped down to f32, I can still see it quite easily under the safelight. Here's a photo of the circle of light (through the grade 2 filter) with the lens opened to f4.5 but with the regular lights on. I use three 500 lumen LED bulbs in this hybrid bathroom/darkroom, so it's not dim by any means! However the light from the enlarger is still very clearly visible. 168626

[Huub]

These very short exposure times happen more often with condensor enlargers. Generally it is a combination the high output of light of the enlarger and thin negatives. Probably there is nothing wrong with your safe lights, lamp, lens or aperture.

Solution is to put a grey filter somewhere in the path of the light. I use a high qualty 3-step one that screws into the filter thread of the lens. There are also grey filters you can put into the filter drawer of the enlarger. You have to do a search here or on APUG to find the place where you can purchase them.

[Pere Casals]

This lens has no such release for the aperture, but I did check just in case! Though it's very precievibly darker at f32 than it is at f4.5. My question I guess would be, how dark should it be? My only logical conclusion is that my lamp is too bright. But I inspected it and it says it's only 75 watts. With the lens stopped down to f32, I can still see it quite easily under the safelight. Here's a photo of the circle of light (through the grade 2 filter) with the lens opened to f4.5 but with the regular lights on. I use three 500 lumen LED bulbs in this hybrid bathroom/darkroom, so it's not dim by any means! However the light from the enlarger is still very clearly visible. 168626


75w from a LED bulb throws x5 to x7 more light than a 75w from an incandescent lamp. For this reason you where needing x7 less exposure time, I guess.

Please post what brightness has the image projected by enlarger, you can obtain the level in different ways:

> A lux meter, like the (Amazon) Leaton Digital Luxmeter, 0.1Lux capable, $16 (interesting to hace something like that in the darkroom)

> Use a Lux Meter app for the smartphone, it uses a sensor that's near screen for screen autobrigth feature. It gives too high readings with directonal light, but still a reference.

> Use DSLR/SLR photometer and say the f/, shutter speed and iso

[AtlantaTerry]

Hello, all.
I just got the final pieces for my darkroom today! So I've started about running tests, the first one is to find my SCT. I'm finding that I'm struggling to get gray tones. Here's my details:

Beseler 45M enlarger w/75 watt lamp
{snip}

My first attempt to print I did three second brackets at f8. So I had exposure times of 3-30 seconds. The entire strip was completely black.

My second attempt I did the same but at f22 and I got two gray tones (so 3 seconds and 6 seconds) with the rest of the strip bring black.

The enlarger head is sitting where it does for enlarging a 4x5 negative to 8x10.

My question is why I'm having to cut down so much light to get usable exposure times? Feels like the lamp is too hot or the lens is too close. But 75w seems appropriate and the head being halfway up the height of the stand seems appropriate also. Can anyone think of what I'm missing?

Any direction would be lovely, I can't figure out what I'm doing wrong.

If memory serves me, a 75 watt light bulb may be too bright. (The last 4x5" Beseler enlargers I worked with were in newspaper darkrooms in the late '60s.)

What does the Beseler manual say is the correct light bulb to use?
Does the bulb you are using have a thick white coating or are you using a "standard" light bulb?

Also, if the light bulb is too intense, the enlarger head will find it difficult to dissipate the excess heat.

For black and white work, you can always use a dimmer to reduce the light intensity.

[Pere Casals]

This lens has no such release for the aperture, but I did check just in case! Though it's very precievibly darker at f32 than it is at f4.5. My question I guess would be, how dark should it be? My only logical conclusion is that my lamp is too bright. But I inspected it and it says it's only 75 watts. With the lens stopped down to f32, I can still see it quite easily under the safelight. Here's a photo of the circle of light (through the grade 2 filter) with the lens opened to f4.5 but with the regular lights on. I use three 500 lumen LED bulbs in this hybrid bathroom/darkroom, so it's not dim by any means! However the light from the enlarger is still very clearly visible. 168626


Please post what brightness has the image projected by enlarger, you can obtain the level in different ways:

> A lux meter, like the (Amazon) "Leaton Digital Luxmeter" , 0.1Lux capable, $16 (interesting to hace something like that in the darkroom)

> Use a Lux Meter app for the smartphone, it uses a sensor that's near screen for screen autobrigth feature. It gives too high readings with perpendicular directional light, but still a reference.

> Use DSLR/SLR photometer and say the f/, shutter speed and iso

[AtlantaTerry]

Solution is to put a grey filter somewhere in the path of the light. I use a high qualty 3-step one that screws into the filter thread of the lens. There are also grey filters you can put into the filter drawer of the enlarger. You have to do a search here or on APUG to find the place where you can purchase them.

If an enlarger has a filter drawer between the light source and film stage, you can use just about any neutral density gel since it does not have to be of optical quality. These 20x24 inch sheet gels are made by Lee and Rosco and are easily purchased from photography stores or firms that supply television / film production studios for about US $8.

[AtlantaTerry]

I tested to see if it was my safelight earlier. I let a piece of paper sit exposed to the safelight for a few minutes and developed it. Pearly white!


That is not how I was taught to test a safelight. What you want to do is in total darkness put something flat and opaque on the paper such as a large coin or small book. And only then turn on the safelight for a minute or two. Then turn off the safelight and develop the paper in total darkness. Once it is in the fixer, then turn on your lights. If you see nothing where the opaque object was sitting then you know for sure that your safelights are OK. What may now appear "pearly white" might not actually be so.

The next thing to do is to expose some paper as above with extended amounts of time to where your paper finally starts to show a difference between the exposed area and where the opaque object was. Then you know the limit that you can not exceed.

Another thing to remember is "base fog" which has to do with sensitized materials - it takes a certain amount of energy start to get them to absorb light. If your safelights are a bit too bright, they can just barely start to expose your paper but not enough to form a noticable fog. But then when you put the paper under the enlarger and expose it in the normal manner you can have inconsistent results.

In my experience, I always wanted a B&W darkroom that was as dark as possible, not one where the safelights were bright. I had only enough safelight illumination to just barely be able to barely make out where my tools were. Of course when I was printing and developing color enlargements, the room had to be completely black so being used to working in a very dark room came in handy.

[TroyG]

My lamp is an incandescent lamp with a white coating. As per the manual, beseler calls for a 150w lamp! The light from the enlarger at working height through my 135mm lens and the grade 2 filter onto white paper is reading EV 6-1/3 on my freshly calibrated Pentax Spotmeter V.

I even checked the voltage throughout the system to make sure it wasn't too high at any point.
It doesn't appear as though they make anything lower output than 75w. I'd be curious to see if I got a different 75w lamp if it would behave differently. This is the lamp that came with it, I didn't buy it. Perhaps this one is brighter by some manugacturing defect?

[Rick A]

Your 75 w incandescent lamp is not the problem. My next thought would be to look at the lens to be sure the iris is operating as it should when stopping down. The lens may not be working properly. I use a 75 watt bulb in my enlarger, and get 20-25 second exposure times for 8x10 enlargement from a 4x5 negative using f-11.

[David Lobato]

My 45MX has an optional Beseler rheostat dimmer called a Resistrol to dim the lamp for situations like yours. Search for Beseler Resistrol for 45MX.

[bob carnie]

Your 75 w incandescent lamp is not the problem. My next thought would be to look at the lens to be sure the iris is operating as it should when stopping down. The lens may not be working properly. I use a 75 watt bulb in my enlarger, and get 20-25 second exposure times for 8x10 enlargement from a 4x5 negative using f-11.

I agree with Rick .. it cannot be the bulb as in my darkroom I rarely if ever use the 75w as not enough power , I normally use a 250 w

Two things come to mind, which are pretty basic.. Is the negative super thin?? and are you using the right chemical mixture for the developer??