Takahashi Dilworth Relay?

ariefm71 · Post by **ariefm71** » Sun Apr 23, 2006 11:16 pm

Anyone know about the 150mm F5.7 Takahashi Dilworth Relay? I believe this is the same design as Mewlon 300 (rest of Mewlons are Dall-Kirkhams).

Markus is selling it for US$1,095. http://www.astromart.com/auctions/detai ... on_id=2336

The drawback is you can not use diagonal with it

wucheeyiun · Post by **wucheeyiun** » Mon Apr 24, 2006 9:12 am

Hi arief, ( a bit of diversion), how is your mewlon 180 as a terrestrial scope ie like watching birds, landscape or neighbours from flats....i i find the mewlon 210 quite good...i can see some very decent land views...but somehow, refractors are still rules...

and also what is the significant difference dilworth relay and dall-kirkhams?

MCYM · Post by **MCYM** » Mon Apr 24, 2006 12:25 pm

Interesting OTA, certainly qualify for collector status. However, optically it may be consider a flop - by design, the native focal plane is buried deep inside OTA, thus relay lens are required to extend the focal plane to a barely usable position outside OTA. Off axis response for Dilworth designs are not purported to be exceptional either. The redeeming qualities are perhaps the faster focal ratio, moderate CO and a truly “limited” numbers in circulation.

Matthew

ariefm71 · Post by **ariefm71** » Mon Apr 24, 2006 12:36 pm

Thanks Matthew!
Chee yiun, I never tried my Mewlon for terestrial as I thought the image will be upside down, same as my Intes-Micro M603. Do you use diagonal?

wucheeyiun · Post by **wucheeyiun** » Mon Apr 24, 2006 1:56 pm

i use WO di-electric diagonal for terrestrial, i get very sharp but not contrasty views of the next block and of the birds and roof tops.
It is vertical image but of inverted sides.