Focal Length: 7mm, 11mm and 18.2mm
Supplier: Telescope House
Telephone: 01342 837098
If you’re into visual observing, then the quality of eyepiece you use is an important issue.
Optical quality can make or break an observation, but your comfort is also very important.
If you’re squinting down a narrow viewing cone, this can become stressful and prevent you from seeing what you’re looking for.
The DeLite eyepiece series from Tele Vue delivers an optically excellent view together with the option to physically adjust the distance of your eye from the eye lens, whether you wear glasses or not.
This makes it really easy to place your eye at the correct ‘eye relief’ to get the best view possible.
The eye relief is the distance your eye must sit from the outer optical face of the eye lens in order to get the intended full angle field of view.
Any closer or further from the lens surface and the view becomes more restricted.
The range includes eyepieces with focal lengths of 7mm, 11mm and 18.2mm.
Each has the same 62° field of view, which we were able to verify by timing how long it took for a star to drift across each eyepiece’s field with our mount’s right ascension drive turned off.
Stars looked sharp through the DeLites and showed little or no false colour; a small flash of blue was seen in the 18.2mm, but only at the extreme edge of the field and only with a very bright star in view.
The view of the Moon was exquisite. Intricate details visible along the terminator were sharp and full of detail.
Our views of the craters Hevelius and Grimaldi were quite amazing.
The high contrast delivered by the 18.2mm eyepiece was superb, but our favourite view was through the 7mm.
The inky dark of the lunar night, contrasting with the bright lunar highlands at high magnification, just kept inviting us to keep exploring.
An unforgiving test
Stars are unforgiving test subjects.
Their pin-point light will cause any optical aberrations to stand out like a sore thumb, especially at the edge of frame, and our test 4-inch apochromatic refractor had excellent optics – leaving the DeLite eyepieces nowhere to hide.
Fortunately, they delivered in spades and the quality of the view was first class.
The 18.2mm eyepiece showed us a large swathe of the Andromeda Galaxy and -with excellent contrast – the dark dust lane truncating one side of the galaxy’s core was very clear.
Satellite galaxy M32 was an easy spot and dimmer M110 quite straightforward to see too.
The 11mm gave the best view, bringing us closer in while maintaining contrast.
The bright star cloud NGC 206, embedded in M31’s southwest arm, was also easy to see with the 11mm eyepiece using our 4-inch test scope.
The 7mm’s contrast was lower and didn’t really suit our 130x magnification view of M31, although it gave us a good view of M32.
M110 was harder to pull out of the background sky but could still just be seen.
Through the 18.2mm eyepiece, Albireo in Cygnus showed deep, rich colours – a beautiful golden yellow primary and azure blue secondary. However, at 50x magnification we wanted something with a bit more power.
The 7mm got right into the action, splitting both stars well, but with reduced colour intensity.
It was the 11mm that really delivered for this target, giving good image scale and deep colour.
The famous Double-Double, Epsilon Lyrae, flipped the situation.
Here, the 18.2mm easily split the well-separated main pair, but splitting these again into their tight components was a struggle at 50x.
The 85x magnification delivered by the 11mm showed each main component to be elongated.
Over time, the comfortable, relaxed view allowed us to see that the elongations were composed of two tiny pin-pricks of light side by side.
Moving the Double-Double to the edge of frame also maintained this view – a great testament to the quality of the optics. The 7mm, of course, split both pairs with relative ease.
These are superb eyepieces, conveniently sized and light. Individually, like their name, they are a delight to use. However, they will tug at your wallet strings and you’ll soon be wanting the whole set.
A comfortable view – with and without glasses
The DeLite eyepieces deliver a fantastic image, free from aberration and very crisp –exactly what a good eyepiece should do.
The 62° multicoated field of view is superb and, placing your eye at the correct eye relief distance of 20mm ensures you get all of that view, just as intended.
We really appreciated the extending and lockable eye guard that provides an accurate and repeatable way to do this without fuss.
The lockable eyeguard and 20mm eye relief means that the DeLites are perfect for those who swap between wearing spectacles too.
Their adjustment means it’s possible to set them for optimum views with or without spectacles in place.
Green markers on the side of the eyepiece barrel provide a convenient way to reproduce the same eye guard position each and every time.
Ultimately, the excellent design of the DeLites provides an eyepiece that you forget about.
Instead you find yourself concentrating on the thing your telescope has been pointed at, and this, after all, is what a telescope and its supporting optics are supposed to do.
These eyepieces are parfocal, meaning that once focused on your target, you can swap between them without having to significantly refocus.
In practice, we found swapping between the 18.2mm and either of the others required the most focus tweaking.
The 11mm and 7mm were very close to one another.
Each eyepiece is equipped with a roll-back rubber eyecup.
This creates a comfortable interface between your eye and the eyepiece, and closes the gap between them to keep things good and dark.
The soft rubber also allows spectacles to be kept on without fear of scratching them.
The eyepieces will fit a 1.25-inch eyepiece holder. Each barrel is shaped to provide a safety ridge.
Should a screw become loose, the expensive eyepiece is less likely to fall to the ground if the telescope swings into a position where gravity takes hold.
Threaded 1.25-inch barrel
All three 1.25-inch eyepiece barrels are internally threaded so that filters can be screwed into them.
This is useful if you want to, say, add a colour filter to the eyepiece to bring out more detail such as features in a planet’s atmosphere or increase the contrast of a faint nebula.
Extendable Eye Guard
Each eyepiece’s outer barrel can be unlocked and extended to just the right length to put your eye at 20mm from the outer surface of the eye lens, at the eye relief of the eyepiece.
This ensures you get precisely the 62° apparent field of view the eyepiece was designed to deliver.
This review originally appeared in the December 2015 issue of BBC Sky at Night Magazine.