Short exposure times - dark prints?

[meeinnj]

Hi,

I have set up a basic darkroom in my bathroom. I seem to be having a consistent problem with my prints coming out very dark; e.g. I have to keep exposure times down to 2-3 seconds to not make the prints too dark. I have had the same issue across several sets of negatives (which all appear OK in terms of exposure.)

I am using a very basic Besseler Cadet II enlarger and it is set to f8.

Any ideas on what sort of things to try to track this down?

Thanks!

- Max

 

[PlasticSpanner]

Try using a lower power bulb in the enlarger.

 

[terri]

And shut that lens down. Try f16 next and see what you get.

And add some filtration, as you can.

 

[meeinnj]

Great thanks! I will stop it down first.

PlasticSpanner - any ideas a where I could find a lower power bulb for my enlarger?

Just curious, does the fstop on the enlarger affect anything other than the amount of light getting through (i.e. like it affects depth of field on the camera?)

Thanks again!

- Max, TPF Noob

 

[JamesD]

From what I understand, f-stop won't do anything funky as long as you are exposing paper which is flat relative to the baseboard. However, say you took a photo of a church steeple (or other upward structure) from the ground; the resulting image will be foreshortend, or appear to be 'tilting back.' From what I understand, you can tilt the paper on the easel to correct this, but the focus will be different between the top and bottom of the image. Using a smaller aperture in the enlarger gives you greater depth of focus (just like depth of field in the camera) so that you can get the whole image in reasonable focus (hopefully).

I could be wrong; anyone else?

 

[Hertz van Rental]

The f-stop of the enlarger lens affects depth of field in the same way as it does in the camera.
You focus with the lens fully open because you have a shallow depth of field and so can get the image sharp.
Then you should always stop down two or three stops.
This increases the depth of field and the depth of focus. It compensates for any unevenness in the neg and in the paper (neither are perfectly flat) to give a sharp print overall.
It will also reduce the exposure time to something manageable - you should be looking for something between 10 and 25 secs. ideally.

Remember: depth of field is in front of the lens, depth of focus behind it. In the enlarger the depth of field is where the neg is, the depth of focus where the paper is.

 

[JamesD]

Hertz, it's sure nice to have you around; you always teach me something! Thanks for the clarification, and giving me something to experiment with in the darkroom. Perhaps I'll improve another degree.