Meade 8.8mm Ultra Wide Angle

	Meade 8.8mm UWA

In the spring of 2006, Saturn came into opposition. Although it appeared quite nice using my Meade Series 4000 14mm UWA, it could clearly use a bit more magnification. After a few weeks of lurking and waiting on Astromart, I managed to find an 8.8mm UWA for sale. The eyepiece arrived in good condition with a few minor scratches on the barrel, but with optics in near perfect condition.

First Impressions

As with the 14mm UWA and other series 4000 eyepieces, the build quality of this eyepiece is top notch. Despite having a smaller eye lens than other 2" eyepieces, this eyepiece has the exact same eyecup as its larger siblings, which is quite nice. The coatings are the same violet multicolored coatings that are used for the 14mm UWA. One nice thing about the 8.8mm verses the 14mm is that it seems to be about half the weight. Although the eyepiece has a nice heft to it and feels really solid, it doesn't have so much mass that I feel uncomfortable holding it in one hand. Often, when toting around the 14mm UWA, I feel inclined to use two hands. Transfering the eyepiece to or from the eyepiece holder of the telescope is always a process that requires some care and attention. With the 8.8mm, I found myself less mindful of the physical bulk of the eyepiece and better able to focus on the view through the eyepiece.

	Specifications Focal length: 8.8 mm Apparent field of view: 84 degrees Number of elements: 8 Optical design: UWA, similar to Nagler Type 1 Manufacturer: Meade Cost: $249 new, between about $150 and $175 used
	Advantages Ultra wide field of view Very flat and sharp across entire field of view Almost no chromatic abberations Neutral color balance High build quality Relativey large eye lens Foldable rubber eyecup Focal plane is located inside of eyepiece, free from dust 8.8mm is a useful and convenient focal length for common F/10 telescopes Reasonable weight and size
	Disadvantages Low contrast Short eye relief - must position eye close to eyepiece Interior of eyepiece could be better blackened - some scattered light from interior surfaces is visible "Kidney bean" / blackout effect when eye is not perfectly positioned Can't see the entire field of view at once - some people may find this frustrating

Field Of View

The 8.8mm UWA is my second "ultra wide angle" 80 degree+ field of view eyepiece after the 14mm UWA. Comparing the two, I was actually a bit surprized to find that the field of view of the 8.8mm is actually slightly larger than the field of view of the well respected 14mm UWA. This was ascertained by holding an eyepiece up to each eye and superimposing the two views. The difference in field of view is actually noticeable - it is not insignificant. Subjectively, I found that the 8.8mm has a more immersive feel than the 14mm possibly due to the fact that your eye is closer to the eye lens and possibly at least partially due to the larger field of view. Like the 14mm, it is impossible to take in the entire the field of view at once and so you need to move your eye to look around the eyepiece barrel to see the entire field of view. The 8.8mm has a significantly smaller amount of eye relief than the 14mm, but in some ways, I actually found that this made it a bit easier to look through. For one thing, the "kidney" bean or "blackout" effect seems to be less noticeable. The effect is still there and can be a bit of a nuissance, but since your eye is closer to the eyepiece, eye position is maintained more easily and the effect is less prevalent. The difference in the magnification and field of view between the 14mm and the 8.8mm is much less than one might expect given the great difference in the size and mass of the two eyepieces. The 8.8mm focal length of this eyepiece is nice because with a telescope of a focal ratio of about F/10, this focal length yields a magnification high enough that it just begins to push the limits of where the image quality starts to break down. This makes it an ideal planetary eyepiece. It may still be nice to have a 4 to 5mm eyepiece for those really exceptional nights when you can push the magnification to the absolute maximum. Alternatively, this eyepiece is compact enough that you could possibly use a barlow lens.

Optical Quality

The 8.8mm, like other UWA eyepieces is sharp right to the edge of the field of view. The only problem with this eyepiece and others like it is that with al of the optical elements and the short focal length, the image contrast seems somewhat low. Also, the lens barrel and housing seems like it could possibly be better blackened to eliminate reflections from the edge of the field of view. When used for daytime viewing, the field stop is not the inky jet black color that it should be, which appears to be a result of reflections from the edge of the lens barrels. I've found this to be a common problem with the UWA eyepiece designs. When used for astronomical targets, this problem is generally not very noticeable. The 8.8mm seems to have a faint touch of chromatic abberation, which I did not notice in the 14mm. Generally speaking, however, I did not ever find this objectionable. Like other high end Meade eyepieces that I have tried, the color balance seems to be neutral.

	Meade 14mm and 8.8mm UWA Eyepieces

Ease of Use

One aspect of this type of eyepiece that I'd like to stress is ease of use. Simpler eyepiece designs such as Plossls and Orthoscopics become progressively more difficult to use as the focal length decreases. By the time they get to 8 or 10mm designs, the eye lenses for these types of eyepieces are tiny and looking through them is like peering through a keyhole. The UWA designs with their integrated Smyth (barlow) lenses change all of that. The eye lens on this 8.8mm UWA is over 20mm across which is about the size of the eye lens on a 25-30mm Plossl or Orthoscopic. This makes the 8.8mm a much easier eyepiece to use. While the UWA designs still have issues with the dreaded "kidney bean" or "blackout" effect, I found that with the 8.8mm, this is relatively easy to avoid since your eye is closer to the eyepiece and overall this is much preferable to the tiny eye lenses of other designs. One shortcoming of the 8.8mm relative to its larger sibling (the 14mm) is that it is very easy to have your eyelashes brush against the eye lens and contaminate the optics. With the 14mm UWA, your eye is always at least 15mm away from the eye lens which makes this impossible. With the 8.8mm, the eye relief is closer to 10mm, which forces you to place your eye pretty close to the eye lens. I've used eyepieces with less eye relief than this, but I would consider this about the limit of short eye relief that I would consider acceptable.

Focal Plane Location

Like other UWA designs, the focal plane of the 8.8mm is located inside of the eyepiece which allows any dust or debris that might get inside of the eyepiece to remain out of focus and unnoticeable. This makes the 8.8mm easy to maintain and use.

Conclusions

The 8.8mm eyepiece is a keeper. I may still at some point see if I can find another shorter focal length eyepiece for those exceptional nights when I can really push the magnification to the limit, but the 8.8mm will probably remain my workhorse eyepiece for high power viewing.