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樓主: luciano

超大型折射雙筒鏡研究中心

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發表於 2008-4-20 21:48:57 | 顯示全部樓層

回復 5# 的帖子

Hi Luciano,

How about Vixen LVW-5mm? similar spec as XL-5.2. Not expensive for buying a pair. Email me please if you fhink this substituion worth thinking.

LT
 樓主| 發表於 2008-4-21 02:08:04 | 顯示全部樓層
原帖由 mca 於 2008-4-20 19:19 發表
Lucianoi

Pentax LX 已停產幾年,我問 HK Grandeye (巨眼) 都沒有 ,建議你直接 post 去 HK Astrofarm 和 「天文論壇」問下有無二手 XL5.2  出讓。

Alan

ps 你支大bino 真係好鬼靚,有創意 ! ...

Alan
唔該晒你的幫忙
 樓主| 發表於 2008-4-21 02:14:33 | 顯示全部樓層
原帖由 LT_5 於 2008-4-20 21:48 發表
Hi Luciano,

How about Vixen LVW-5mm? similar spec as XL-5.2. Not expensive for buying a pair. Email me please if you fhink this substituion worth thinking.

LT

LT_5您好!
兩目鏡倍率不同系唔可以用系雙筒鏡度,主要有兩個原因,一兩像是不能重合,二系會睇到到頭暈,
但都很多謝您的幫忙。
發表於 2008-4-21 04:18:38 | 顯示全部樓層
支大bino 真係好鬼靚!
發表於 2008-4-21 10:57:36 | 顯示全部樓層
原帖由 luciano 於 2008-4-21 02:14 發表

LT_5您好!
兩目鏡倍率不同系唔可以用系雙筒鏡度,主要有兩個原因,一兩像是不能重合,二系會睇到到頭暈,
但都很多謝您的幫忙。 ...


LT_5係建議你買一對LVW 5mm:
發表於 2008-4-21 12:10:19 | 顯示全部樓層
Wah!!! 太震撼了!!!
發表於 2008-4-21 12:57:33 | 顯示全部樓層
我用緊兩支 Vixen 目,24 - 8 mm zoom 和  LV 2.5 mm ,好滿意,它們的 eyerelief 夠長,久看眼睛也會舒服些 (如果用 Ortho 目鏡就睇到眼淚水都出埋黎)。4 月15 日個晚,我用 Vixen LV 2.5 +  10-in f/6 牛頓 (630X) 目視在月球明暗分界的 Copernicus dome,雖然 seeing 差,也看足10 分鐘。順便贊下 Bob Royce 的 mirror,我的 10-in f/6 係佢磨,好 seeing 時,放大到 1080X (配 Tele Vue 5X Barlow + Tak 7.5 mm eyepiece) 一樣掂。

AC
發表於 2008-4-21 13:29:22 | 顯示全部樓層

Pupil inter-distance in big bino

Dear Lucianoi,

Just a thought from me:

Pentax XL5.2 體積肥大,筒身直徑足足有 60mm,如果用兩個 XL5.2 做你支大 bino 的目鏡,pupil inter-distance 可能過大,左右眼兩個影像鏡不能合成到 Stereo 效果。

AC
發表於 2008-4-21 16:25:20 | 顯示全部樓層

回復 17# 的帖子

All LV series have been replaced by NLV ones. Optically they are identical but only the rubber eyeguard changed to  twist-up ones.

If just for casual use and more convenience in changing power, the zoom LV not too bad. However, for better visual performance, fixed focal length is preferrable.

Just my 2 cents,

LT
發表於 2008-4-21 16:41:40 | 顯示全部樓層
Advice to those having LV-2.5mm:

My experience in using LV-2.5mm was that the diffraction effect due the the small size of its field lens became more obvious when the seeing was bad, especially on those large catadioptric type telescopes. So, avoid using it under such a sky condition. Otherwise, the image might become very soft and unsharp at high power.

Moreover, avoid stacking a barlow in using LV-2.5 due to the diffraction effect increased by doing so (my guess only).

Best scopes for LV-2.5 are good refractors and Newtonians of small CO.

My 2 cents again,

LT
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