TeleVue Plössl 40mm 1.25" - Eyepiece

TeleVue Plössl 40mm 1.25" : Eyepiece: classic TeleVue Plössl eyepiece

The TeleVue Ploessl 40mm is the specialized long model in the 1.25-inch series. The field stop is 27mm, the same as the 32mm; the apparent field of view is therefore narrowed to 43 degrees. You see the same piece of sky, but at lower magnification and through a narrower window.

The reason to choose it is the combination of the lowest possible magnification with a very long eye relief of approximately 28 mm.

The TeleVue Ploessl design

Four lenses in two groups are all a good Ploessl needs. Because there are few glass surfaces, transmission remains high and contrast is maximized: precisely the characteristics that matter for planetary and lunar observation.

TeleVue T-type optics brought the design to the current level in the seventies, with tight manufacturing tolerances, multiple coatings, and blackened lens edges. You can see the difference compared to a standard supplied eyepiece right at the edge of the field.

When 40mm is the right one

On slow telescopes like a Maksutov or Schmidt-Cassegrain, the 40mm provides the lowest usable magnification, with an exit pupil that stays neatly small: at f/10, only 4mm.

The long eye relief is also an advantage when observing with the whole family: children and eyeglass wearers find the image without searching. For fast telescopes, the 32mm is the better choice, with the same field and a wider window.

In your telescope

In a telescope with a 1200 mm focal length, this eyepiece delivers approximately 30x with a true field of view of about 1.29 degrees. For your own telescope: true field of view = 57.3 x field stop divided by the telescope's focal length.

The effective field stop of this model is 27.0 mm.

Featured accessories

A TeleVue 2x or 3x Barlow lens doubles or triples the magnification of any Ploessl eyepiece without any loss of quality; two Ploessl eyepieces plus a Barlow lens thus cover four magnification levels. Models 25 mm and larger also accept the Dioptrx astigmatism corrector.

For whom yes and for whom no

• Slow telescopes like Maksutovs and Schmidt-Cassegrains
• ✓ Ring bearers and public evenings
• The lowest magnification in a 1.25-inch focuser
• ✗ Fast telescopes, the exit pupil gets too big
• ✗ Anyone expecting a wide apparent field: this is 43 degrees

Specifications

You can find the complete product line for this merk at the TeleVue merk Page.