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SPL eyepieces now in production

Started by RolandC, 07/29/2004 11:47AM
Posted 07/29/2004 11:47AM Opening Post
Hi All,

Sorry to take you away from your 10" Mak soap opera, but I wanted everyone to know that The first production run of SPL eyepieces is in production. I have just finished assembling the 12mm versions and now working on the 10mm (working my way down).

After finishing the first batch, I could not resist doing the infamous "sidewalk test". I compared the contrast and back scatter of the 12mm SPL against my pristine 16mm Zeiss Abbe Ortho, a 17mm premium Plossl and a 19mm premium Widefield ocular (see attached image).

For those who don't know this test, it is a way to compare the relative contrast of two or more eyepieces. The test was first suggested to me by the owner of our coating lab to gauge the effectiveness of anti-reflection coatings on an eyepiece. The idea is to place the test eyepiece on the ground on a blue-sky day so that the light from the sky illuminates the optics from the eye end. Any light that bounces around inside and comes back up out of the eye end is an indication of the internal reflections and scatter at the various surfaces. The brighter the eye end of the eyepiece looks, the more reflection and scatter it has.

I'm happy to say that the new SPL oculars are as contrasty and free of scattered light as my pristine Zeiss Abbe Orthos. Note also the size of the eye lens, which is an indication of the eye relief (typically the bigger the lens the longer the eye relief is). Note that the 12mm SPL has almost the same size eye lens as the 16 Ortho, and nearly that of the 17 Plossl. The eye relief of the 12mm is very nearly the same as these oculars.

Roland Christen

Attached Image:

RolandC's attachment for post 17721
Posted 07/29/2004 05:29PM #1
Really nice Roland, are you posting prices as yet for these masterpieces? smile

[SIZE="Large"][/SIZE][COLOR="Blue"][/COLOR] Floyd Blue grin
Amateur Imager
Posted 07/29/2004 10:37PM #2
Nice comparison Roland. I'd say the 12SPL looks darker than the Zeiss in your picture. The backgroung is about the same but the solar disk seems brighter in the Zeiss than the AP. Does the coatings on the SPL's impart a tint to the view?

"I know engineers. They love to change things."

- Leonard McCoy (Star Trek: The Motion Picture)