I'm designing a focusing mechanism for triplet lens to be able to move the PJ form room to another.
and since the pro triplet is about 7cm thick, I need to ask a question about the distance from LCD to triplet lens that the focal calculator presents.

is this distance ends at the tip of the lens that faces the LCD panel? or ends at the center of the whole triplet?

Thanks all

Click to view attachment

My understanding is to the center of the triplet

2 things - first peak350 is right. second, for the pro lens, the flange will be facing towards the LCD - basically the opposite as you have in the pic.

Ok thanks guys..



I actually read a post on the forum, this guy said that he used it that way " like the pic" and the focus was bad.. someone told him to flip it, and that it might be assembled the wrong way..
thanks for the tip.

Oo..
Guys, anyone know where to find Haas man design for the 17" LCD??

Pretty certain SupraGuy has determined the optical center of the pro lens to be near the flange (for a stock configuration).

Knew I should have said [I think] peak350 is right.... must be thinking of the standard triplet..

It should be noted the precise optical center of the lens is considered undetermined and one should always allow for at least 1 inch (2.54 centimeters) of adjustability (in each direction - fore and aft) in any build. Didn't your Mother ever tell you "Better safe than sorry".

Well, yeah.. not in these words, but yeah..

the thing is I'm gonna design a 12cm focusing mechanism (6cm in each direction).. so I need a point to start.

Use the second diagram.

DJ