The Olivon T90 and T90ED are almost identical in every way, both have a 90mm objective lens, their optics are fully multi-coated, both have Bak4 prisms, they are both waterproof and nitrogen filled to prevent fogging and they both give fantastic sharp bright images.

The only difference, and it's a big one, is the T90ED version uses high-quality optical lenses that have a high content of fluorite, which reduces deviation in images. These special lenses are called ED (extra-low dispersion) lenses, and are mainly used in powerful telescopes. This model not only gives super clear and crisp images, but it also provides extraordinarily sharp resolutions. These lenses don't come cheap, at £650 retail, the T90ED is over twice the price of the standard T90.

There's no question that the optical performance of the T90ED is superior to that of the T90. When I first used my standard T90, I was amazed at the results, it was so clear and sharp. I wondered how the T90ED could beat such a high standard. After testing the 90ED and non ED under identical conditions, I noticed that the T90ED captured extra detail than the T90, the images also seemed to have a more 3D quality to them and even the smallest details were crisp and sharp. The difference wasn't massive, but it was there.

As a digiscoper, I was very interested to see if these subtle differences would be captured by a digital camera and if so, would the combination of a T90ED and digital camera give better digital images than the standard version.

On a cold but bright Sunday morning, I took both scopes out in to the garden and with my Nikon Coolpix 4500 attached, I took some photographs.

I have tried to be as fair as possible when testing the two scopes, using the same camera settings and taking pictures of the same subject matter within a few minutes of each other.

Click here to read on and view the results.

The Olivon T90 and T90ED specs

  • 90mm objective
  • Angled eyepiece setting
  • Field at 1000m: 31m-15.7m
  • Aperture field: 40-60 degrees
  • Exit pupil: D4.1~D1.4
  • Eye relief: 18-15
  • BAK4 prism
  • Focal length of scope: 540mm
  • Focal length of eyepiece: 8-24
  • Magnification: 22-68x
  • Close focus: 8-10m
  • Multi-coated lenses
  • Fog proof (nitrogen filled)
  • Water proof
  • Quick release shoe
  • Camera adaptable
  • Rubber armour
  • 360 degree sleeve
  • Soft carry case



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The content is my own diary and findings. I accept no responsibility or liability if you choose to follow my advice.

The advice, reviews and opinions expressed in this website is based purely on my own findings and preferences and should be treated as guidance only. You may find other settings work better for you and your equipment.