Bonjour à tous,

à titre d'info, je vous joins le texte original du test de la longue-vue Diascope 85 FL de Zeiss effectué par un spécialiste britannique reconnu de la digiscopie, Andy Bright :

"Digiscoping with the Zeiss Diascope 85FL

When Zeiss announced the new Diascope 85, many of us ‘digiscopers’ were excited by the prospect of a compact and lightweight scope with the added benefit of an 85mm objective lens. The benefits of its size and weight are clear to every birder but the larger objective lens is especially desirable for digiscoping. A larger lens means faster shutter-speeds to help freeze the action, whether this action is at the user’s end due to camera-shake, or at the other end if the subject is moving. To some extent and depending upon implementation, a larger objective lens can also increase the resolving power of the scope, i.e. greater detail.

Courtesy of Zeiss U.K. I tested the Diascope 85fl with 20-60x and 40x eyepieces for 2 months from a digiscoping perspective. The 40x eyepiece was just a little too powerful for digiscoping use. My own preference is for the flexibility of a zoom eyepiece but the Zeiss 30x will be very suitable for those who prefer the fixed variety.

The twist-up/down eyecups were very efficient; in the lowered position they do not protrude above the eyepiece glass, therefore allowing the camera lens to get very close and minimise vignetting.

The scope uses a twin focus knob system; I’m not huge fan of twin focus designs with the view that a single well geared control is good enough and that a fine focus knob can encourage unnecessary fiddling. I know many that @#$%& their dual controls and no doubt Zeiss would have been criticised by many if they hadn’t decided on that route.
In addition there is a nice long lens shade that pulls out over the objective lens, sitting upon the shade is a sighting device consisting of an elongated vee, so as not cause any parallax problems.

A major bonus was that the design of the zoom eyepiece is such that it can be rotated with the camera firmly attached via a typical digiscoping adapter. Digiscopers using other scopes are currently paying small fortunes on specialised adapters that have cutouts to allow zoom operation.

Vignetting was minimal @20x on the zoom eyepiece, disappearing completely when the camera zoom was increased to one third of it’s range, even at higher magnifications on the eyepiece there was plenty of travel in the camera zoom before vignetting appeared.

There is some minor distortion around the edge of the image with the 20-60x at 20x, this caused by the extra wide field of view presented, but it’s of no importance from a digiscoping perspective and disappears very quickly as the zoom is increased.

Performance was very good with the resolution from this scope at above 30x being exceptional (it’s class leading above 40x). The image is indisputably brighter than any of its competitors, though I felt there was a slight price to pay for this in terms of contrast when compared to the other high-end scopes. Although contrast can be boosted in-computer/in-camera, it does aid focussing the scope via the camera monitor if a high contrast image is presented by the scope in the first place.

Andy Bright"

Optique et Photographie

Test digiscopie avec la longue-vue Zeiss Diascope 85FL