PEAK Focus magnifiers (focus scopes)

PEAK Focus magnifiers (focus scopes)
Design and construction of focusers
A focus magnifi er or focuser consists of a mirror, magnifi er and adjustment screw, see Fig. 1. The
bottom of the adjustment screw and the contact surface of the instrument are positioned precisely
symmetrical to the mirror. When the enlarged image of the negative is focussed at the bottom of the
adjustment screw, it is automatically focussed on the photo paper, when the focuser is removed from
the base plate of the enlarger. The focus remains correctly set when the focuser is located offset to
the optical axis of the enlarger, as shown in Figure 2.
Mirror
Magnifying lens
Operation of focusers
Magni�er
Focusing screen
Eye
Photopaper
These focusers not only allow you to focus your magnifi er on
the image centre point; focusing is possible on any desired
point in the entire image area. This allows you to fully use
the capabilities of your magnifi er to obtain brilliantly sharp
images.
Figure 1 Figure 2
Switch on the light in the enlarger and place the focuser on the base plate. Adjust the focuser so
that the image on the adjustment screen is sharp. Then adjust the enlarger so that the negative image
is focused on the adjustment screen. Place the focuser on the base plate in areas important for
the image. Fine-focus the enlarger. The grain and profi le should be clearly visible on the adjustment
screen. After completing the above steps the enlarger is focussed. Then remove the focuser from the
base plate, place the photo paper on the plate and expose the paper.
– 1 –
Magnifying lens
θ°
Optical axis of
magnifying lens
θ°
θ°
Magni�er
Focusing screen
Optical axis of
magni�er
Mirror
Eye
Photopaper

PEAK Focus magnifiers (focus scopes) 2000
PEAK Focus magnifiers (focus scopes) 2020
Ocular 10x
Optical characteristics Two lens systems with three elements
Angle Angle infi nitely adjustable up to 30°
Mirror 86 x 26 mm
Dimensions 160 x 140 x 80 mm
Weight 643 Grams
Accessories BG Filter included
The focuser is equipped with a Kellner magnifi er and 86 mm long mirror. Since the magnifi er can
swivel, the image is focussed in the area where the optical axis of the enlarger lens forms an angle of
approx. 30° to the optical axis of the magnifi er. Model 2000 has a die-cast aluminium housing with
high quality black enamel fi nish.
Order no. Description Price excl. VAT.
2000 Focus magnifi er 290.00 J
Delivery: Incl. packaging, freight charges see www.m-service.de
Payment: 30 days, net
Ocular 10x
Optical characteristics Two lens systems with four elements
Angle 20°
Mirror 53 x 27 mm
Dimensions 140 x 140 x 65 mm
Weight 280 Grams
Accessories BG Filter optional
This model is based on the 2000,. Use of a special wide angle magnifi er allows the image to be focussed
in the area where the optical axis of the enlarger lens forms an angle of approx. 20° to the
optical axis of the magnifi er, as long as the magnifi er and base plate are not moved. The 2020 has a
fi bre-glass housing.
Order no. Description Price excl. VAT.
2020 Focus magnifi er 135.00 J
Delivery: Incl. packaging, freight charges see www.m-service.de
Payment: 30 days, net
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PEAK Focus magnifiers (focus scopes) 2030
Ocular 10x
Optical characteristics Two lens systems with two elements
Angle 10°
Mirror 43 x 26 mm
Dimensions 140 x 140 x 65 mm
Weight 174 Grams
Accessories BG Filter optional
This model is also based on the basic principle of the previous models. The image can be focussed in
the area where the optical axis of the enlarger lens forms an angle of approx. 10° to the optical axis
of the magnifi er.
Order no. Description Price excl. VAT.
2030 Focus magnifi er 75.00 J
Delivery: Incl. packaging, freight charges see www.m-service.de
Payment: 30 days, net
1. Focussing deviations
resulting from differences in the thickness of the photo paper
To focus the focuser it is most practical to place a piece of photo paper beneath the instrument to
prevent deviations in the focus resulting from differences in the thickness of the photo paper.
2. Selection of aperture for focussing
If the aperture on the enlarger is opened fully to adjust the focuser and exposure is then accomplished
using the working aperture, shifts can occur in the focus due to the aperture error of the
enlarger lens.
3. Primary point measurement
Place the focuser on the base plate so that the image is focused in the important area.
4. Focus deviation
Selecting a magnifi cation factor greater than the range for which the lens is designed results in image
errors where the focus differs between the middle and edge area of the image. The focus should
be checked with a focuser even on enlargers with auto-focus.
5. Use of BG fi lter
The BG fi lter can be places on the focuser ocular to achieve more precise enlargement of black/white
fi lms. The fi lter ensures that the response sensitivity of the eye is matched to that of the enlarger.
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