Lens and cell
Using Hoya FCD100 glass the lens offers crisp and sharp optics for imaging and visual astronomy. The collimation screws are neatly hidden behind the dew shield. The field of view is impressively flat to almost the corners of the image and any star distortion is only seen on the largest of camera sensors. Imaging with an IMX 294 sensor showed the tiniest distortion in the corners of the image. The lens cell is a little different to most telescopes in that it is made of steel and not alloy. The problem with large lenses held in alloy is they can distort under rapid temperature changes. The manufacturer has changed the design a few times and this latest innovation is a good solution to an old problem that appears to have paid off; the optics were very stable throughout the review period and needed next to no focus adjustment during imaging sessions. The only downside is a little extra weight on the front of the telescope.