Rodenstock CA 30

Discussion in 'Enlarging' started by elmisty, Feb 8, 2010.

  1. elmisty

    elmisty Member

    Feb 8, 2010
    Couple month ago I have received Rodenstock CA 30

    1. Does anyone have experience with it? When I read manual to it I feel like real blond looser
    2. Is it suitable for B&W photography? If yes, than how can I properly operate it? If not, than what would you recommend to search for?

  2. Ed in SoDak

    Ed in SoDak Member

    Dec 2, 2010
    it's all good


    It's been a few months since your post, but for you and others who might have one and end up here looking for info, I used the Rodenstock CA 30 for many years to expose color and B&W prints and it works great.

    I haven't printed in a long while, basically I went digital, but I still have all my old gear. Cleaning up the accumulation, I came upon my old one and decided to google it, which brought me here.

    Like any exposure meter, calibration is the key and must be done to your own methods of processing and exposure techniques plus personal preferences and choice of materials.

    For cameras, it's pretty easy, just set the ASA/ISO dial and shoot, or apply your own formula to set the "proper" speed of the film you're shooting. Printing papers don't have such clear-cut guides such as ASA 100, ect., as there's way too many variables in the darkroom to simply put a number on the paper box and state that's what you should use.

    Where you place the meter under the enlarger image can have an influence on the reading, so that is important. Select a portion of the image that represents the tone you wish to meter, much like using your camera's meter. You can meter shadows, highlights or mid-tones, whichever suits your style. The Rodenstock came with a diffuser which fits under the lens that blurs the enlarger image to a "steamy shower door" sort of blurry generality of tones.

    You can also skip the diffuser and use it sort of like a camera's spot meter, but it must be calibrated for the increased light coming from the enlarger without the diffuser in place.

    Regardless, by trial and error, I generally make a "good" print that has the tones I like and then I calibrate the meter to match that exposure. I leave the lens at whatever f-stop I chose for the exposure, and rotate the seconds dial on the meter to match the time my test print required. Next, rotate the "E" dial until both LEDs light equally, with the sensor placed under the "appropriate" spot beneath the enlarger. With the diffuser in place, this is not difficult, as the image is fairly uniformly blurred, so precise placement isn't absolutely necessary.

    Now, place a new negative in the enlarger and take a reading. Put the sensor in about the same "sweet" spot as was found by your calibration tests and either adjust the enlarger lens to make both LEDs light or turn the time dial on the meter to set a different time if you want to use the same f-stop. The general exposure of the metered area will agree with your test print if you were successful.

    To extend this tutorial to also set the color dials, it requires repeating these basic steps for each of the three colors, plus the primary exposure, the only difference being you first set basic exposure, then adjust the cyan, magenta and yellow levels, finally fine-tune the exposure again to compensate for the color adjustments.

    Once you get on a roll, the meter will clue you to any differences between one image and the next. For color work, keep in mind a tree scene will obviously have a different overall color balance than an interior shot, fo example, so it's not always necessary to make the color settings agree from one print to the next. The individual color intensities should be different for scenes taken under varying conditions. But, for a series of print shot in the same location, it will clue you to changes in the overall color, and that is useful info to have.

    For B&W work, simply ignore the color portion of the meter and use only the E wheel.

    It's an art and a science and will take practice to properly calibrate it and judge the best areas to place the sensor for the best readings. Just about like setting exposure in the camera, most all readings require at least a little interpretation and some experienced judgement for the best results.

    Good luck and happy printing!

    My first post here, BTW. I just found the place and will check back in!