Kowa TSN-66 Prominar telescope
Visitors to this year's Global Birdfair will have had the opportunity to view Kowa's latest addition to its TSN telescope range, namely the TSN-66 Prominar. Birdfair marked the official global product launch of this new model, which went on sale in September and is available in both straight- and angled-body versions.
A 66-mm TSN Prominar has been available before, namely the TSN-663M, but this new version is a different animal which represents a significant upgrade and it has been designed and constructed with portability being a fundamental prerequisite. That's not to say that Kowa doesn't have a smaller scope in the range, in the shape of the TSN-553 travelscope, but the latter has limitations insomuch as it has a 15-45x eyepiece that is not interchangeable.
The new 66 is set up to combine the best of both worlds. It's shorter in length than its predecessor (although the body is just over 100 g heavier), it has a closer focusing distance and is designed to accommodate different eyepieces. With respect to the latter, the two options being promoted as offering the best compatibility are the TE-11WZ II 25-60x zoom wide-angle eyepiece and the TE-80XW 35x fixed-magnification extreme wide-angle eyepiece. Depending on the choice of body and eyepiece combination, the total weight ranges from 1,500 g to 1,640 g.
Eyepieces form part of a number of key differences from the original 663M, the eyepiece of which was from the old 600 series and had a narrower field of view. The prism housing in the new model is of a better design but, most importantly, the objective lens is now top-grade fluorite crystal – a significant departure from the old series, which used only ED glass. As such, this latest 66 now forms part of the 'new' Prominar line that includes the TSN-99 and TSN-88, all of which share the same accessories. There will no longer be a TSN-770 series and there are no immediate plans to replace it.
I was able to acquire a straight-bodied version, the TSN-66S, along with both of the above eyepieces, which provided a great opportunity for some early autumn field testing.
Compared to the TSN-663, which is no longer available, the new 66 takes on an updated, more modern appearance in line with the two larger models. This includes a swish black rubber-shrouded external top to the prism housing and a reshaped mount for the dual focusing wheels, which are now more exposed, allowing better finger contact.
These wheels have a broadly ribbed, non-slip rubber covering and, turning very smoothly, they can be rapidly operated in conjunction with each other by simple index and middle finger contact.
The body itself is constructed from magnesium alloy and the only other use of rubber is the covering on the pull-out objective lens hood. The latter has an integrated aiming sight and, when closed, sits flush with the objective mounting. This means that it does not accommodate the spring-clip lens cap when extended, the latter clipping neatly into the body only.
Redesigned, too, is the tripod mounting system which consists of two screw holes to add solidity and negate the tendency to work loose and spin when attached to a quick-release plate. I would like to have seen an ARCA-SWISS-style tripod foot, since many tripod heads now have the ability to accommodate this type of foot without the need to attach a quick-release plate, thereby offering better security and increased stability. The tripod foot is attached to a rotating body ring which provides seven locking positions.
Both of the aforementioned eyepieces can be quickly inserted or removed and they are secured by an internal locking system, which can be quickly released by pressing a small button on the lens mount on the side of the body.
Having been impressed with the TSN-99 when I reviewed it back in 2021, I had every reason to believe that its smaller sibling would perform equally well for its size and specification. I was not disappointed. This neat piece of kit lived up to my expectations in terms of the image it delivered.
I was able to test it in a variety of habitats but wetland scored over woodland in terms of enabling viewing over long distances, although use in both habitats was necessary to provide a background to test colour fidelity. Both eyepieces performed extremely well and the first aspect to strike me was the brightness of the image in each case. To my eyes, that delivered by the 35x fixed-magnification wide-angle eyepiece appeared to be marginally brighter than that produced by the zoom when set at the same magnification. The difference in the field of view at this setting was also very obvious indeed.
Using and adjusting the dual focusing wheel was simple and provided no barrier to quickly obtaining a sharp image throughout the whole of the magnification range.
Chromatic aberration was at a very pleasingly low level in each case – so much so that I didn't notice it until I seriously started to look for it. Furthermore, there was no apparent distortion across and around the image which, with both eyepieces, remained razor sharp to the edges of the field in each case.
This enabled the appreciation of plumage colour tones in Ruff and moulting adult Black-tailed Godwits at one of my local wetlands, as well as Common Redstarts and Whinchats in open areas of woodland and fields.
Vegetational colours of different habitats were also very accurately delivered, with stubble fields appearing as true-to-life, bright straw-coloured and free from any brownish tinges evident in some optics.
The bottom-line assessment of the 66 is that it achieves what it sets out to accomplish. Unless you feel especially that you need a large telescope – be it for higher magnification or that little extra light-gathering capacity – this modestly sized piece of equipment is likely to tick just about all the boxes. It's not cheap, however, and represents an enormous leap in price above the ageing TSN-663. The usual accessories (digiscoping and astronomical eyepiece adapters and so on) available for the larger models are also compatible and a neoprene stay-on case will add a further £189 to the package.
Find out more about the TSN-66 at www.kowaoptic.com/
Further info
- Price: £1,759 (TSN-66A/S body only); £690 (TE-11WZII zoom eyepiece); £649 (TE-80XW extreme wide-angle eyepiece)
- Size: 310 mm (TSN-66A body only); 295 mm (TSN-66S body only)
- Weight: 1,135 g (TSN-66A body only); 1,155 g (TSN-66S body only) 365 g (TE-11WZII); 485 g (TE-80XW)
- Magnification: 25x-60x (TE-11WZII); 35x (TE-80XW)
- Field of view at 1,000 m: 42-23 m (TE-11WZII); 45 m (TE-80XW)
- Light transmission: not available
- Close focus: 3.5 m
- Gas-filled: yes
- Waterproof: yes
- Guarantee: 10 years plus additional 5 years upon free registration
Verdict
+ Razor-sharp image quality
+ Excellent colour reproduction
- Slightly heavier than predecessor
