17.3 Delos details

[NGC 1502]

Hi all. I attended Astrofest on Friday 10th, and the new Televue 17.3 Delos was on view.

Here it is - Tele Vue Optics: Delos

I spoke to David Nagler (who is very friendly and approachable) and asked him about the unconventional focal length.

He explained that the design brief was the longest focal length in a 1.25" barrel with the 72 degree field and 20mm eyerelief, plus of course a sharp to the edge high contrast view.

The prototype had a focal length of 18mm. However, when they tried it, they were not satisfied and felt it could be better. the design was tweaked, and came out as 17.3mm. David explained further that if it had been 17.1 they may have called it a 17, or if it had been 17.4 perhaps it would have been called a 17.5. But the design they were happy with came out at 17.3, so that's what they have called it.

I think that's testimony to TeleVue to do the best they can. They know that their products are going to be stringently reviewed by us, the astronomy community. I'm sure they would rather have comments about a strange focal length than about a product that is less than excellent.

Regards, Ed.

[bombassa]

Hi

Nice report.

This must be like candy for eyepiece afficionados.

Visiting astrofest (or similar) must be fun. If only I could go

[rwilkey]

I saw it today (Saturday) and what a feast for the eyes it was!

[John]

Interesting report Ed - thanks

Tele Vue tend to have a good reason behind all their design choices so I'm not entirely surprised.

I wonder if David got any flack over the recent price rises ?.