Fernando np
Well-known member
Recently, I've bought a 5 mm TeleVue Radian eyepiece. This item is 1 1/4" size so an adapter is compulsory. The're two alternatives. I've choose the zeiss one, mainly by hazard. None can say it's user friendly for fast change. Schrewed, I'd had prefer the bayonet sistem, as the standar zeiss 2" eyepieces. Baader has a bayonet adapter for round the same prize. If somebody is interested in the Baader, first confirm if it's posible to focus to infinite.
Let's go to the fields. My first try was in a very interesting dumping site. I'm very used to birding there. I started sit with the tripod at its lower high. The Televue Radian it's heavier then the Zeiss Vario 20-60X.The theory says it gets a 100,4 power. The pupile relief probably is the claimed by the maker, 20 mm. My first aim was a red kite over a pine. The level of detail was higher compared with the zeiss zoom. I'm sure if you take a micrometre and gauge the minimum detail you can see over the eyepiece surface, TeleVue will be the winner. The loss of brigthness was less important I'd been feared about. With such superb detail the comfort of view suffers from the narrow field and the depth of field. This last is almost zero. At round 200 metres and perched in a branch, the kite was cleaning their feathers with their claws fixed. Believe me or not, I had to refocusing depending of their movements. I've kept next days and it shows me new levels of details, as perfect nails in wagtails, and eye colours. Of course the distance I can read leg rings is bigger now. But there's a cost for the eyes, usually the eye. Narrow and shallow field of view fight against the confort of view. I've rememberd, there must be a question of age, when I worked doing chamoise and roe deer census. Although the Zeiss 10x40 binoculars were my main tool, sometimes more power was needed. Which was provided for an 60 mm Opticron spotting scope. The same scope, I believe, was also sold under other branches. At 45X a new world of detail was born. Unnatural, compared with through the binoculars, and tiring but useful. I'm sure The cost of the new eyepiece will be amortized but the zeiss zoom will kept being the usual implement.
Let's go to the fields. My first try was in a very interesting dumping site. I'm very used to birding there. I started sit with the tripod at its lower high. The Televue Radian it's heavier then the Zeiss Vario 20-60X.The theory says it gets a 100,4 power. The pupile relief probably is the claimed by the maker, 20 mm. My first aim was a red kite over a pine. The level of detail was higher compared with the zeiss zoom. I'm sure if you take a micrometre and gauge the minimum detail you can see over the eyepiece surface, TeleVue will be the winner. The loss of brigthness was less important I'd been feared about. With such superb detail the comfort of view suffers from the narrow field and the depth of field. This last is almost zero. At round 200 metres and perched in a branch, the kite was cleaning their feathers with their claws fixed. Believe me or not, I had to refocusing depending of their movements. I've kept next days and it shows me new levels of details, as perfect nails in wagtails, and eye colours. Of course the distance I can read leg rings is bigger now. But there's a cost for the eyes, usually the eye. Narrow and shallow field of view fight against the confort of view. I've rememberd, there must be a question of age, when I worked doing chamoise and roe deer census. Although the Zeiss 10x40 binoculars were my main tool, sometimes more power was needed. Which was provided for an 60 mm Opticron spotting scope. The same scope, I believe, was also sold under other branches. At 45X a new world of detail was born. Unnatural, compared with through the binoculars, and tiring but useful. I'm sure The cost of the new eyepiece will be amortized but the zeiss zoom will kept being the usual implement.
