Re: Horizon 202 focus

[Willem-Jan Markerink <w.j.markerink@xxxxx>]

On 10 Nov 98 at 14:49, Leong, Ka Tai wrote:

> On Mon, 09 Nov 1998 18:36:44 +0000 Willem-Jan Markerink wrote:
> 
> >Well, according to the manual, you shouldn't expect any object in
> >focus closer than 3.9m (@f4.0)....;-))
> >1.5m is only in focus at f11....
> 
> The manual that comes with the camera is in Russian <g>. It appears to be
> very detailed and comprehensive, but useless to me.

But numbers read the same in Russian and English....8-))
There is only one table in it dealing with DOF....;-))
 
> >No, not at wider apertures anyway....for smaller apertures you could
> >fabricate a diopter, but it would have to be very low numerically
> >(fractional, 1/8 or less), otherwise you would not be able to focus
> >on infinity.
> 
> That is an idea. Perhaps I can glue somthing on one of those clever little
> filter holders. You have experience doing that. Could you give me some
> pointers -- do's and don'ts.

But WHY do you want a diopter?
The ONLY way to get both infinity and close-up in focus is stopping 
down....diopter or not....otherwise you loose either infinity or 
close-range. You only gain a little by decreasing the 
close-up focus with a diopter, but at the same time you'll need to 
stop down to keep infinity in focus....and the image degradation 
might be worse than the gain at close range....
The practical problem is that very slight diopters are hard to find, 
and pretty expensive....all scientific supply stuff....
(you can't buy a big one and cut several small ones out of it, no
matter how smart your cutting....there is simply only one center to
work with....8-)) 

> BTW, I seem to have problem with Ilford Delta 400 film. Difficult to load.
> Hard to advance and rewind. I have already torn off one roll of Delta. No
> problem with Kodak CN400. Anyone else share this experience?

Different films can indeed result in very different 'tension'....
On my homepage, I have a chapter containing some tips and tricks to 
deminish this film-/perforation-ripping problem....which can happen 
with any film if you want to squeeze out those last few mm's of film for 
one more shot....

http://www.a1.nl/phomepag/markerink/mainpage.htm


--                 
Bye,

Willem-Jan Markerink


      The desire to understand 
is sometimes far less intelligent than
     the inability to understand


<w.j.markerink@xxxxx>
[note: 'a-one' & 'en-el'!]