Re: [APML] 4X5 camea and Aero Ektar Lens

[George Anderson <georgea@cam.org>]

Hi Mike

I think that you will find the Aero-Ektar is truly achromatic and the
focus for the blue will be way off from the red. So much so that colour
film may be a loss.
That being said, is there anyway that you could mount a minus violet
filter behind the lens inside the box? It may make the camera a little
nicer when you try shooting colour.
>From your hartmann tests was there a shift in focus for each of the
colours? If the shifts are repeatable then tricolour 4 by 5 on B&W film
might be the route to go.
Whereabouts in Oz are you located?

George Anderson
Montreal Canada

Clear skies and good health

> M/S Heald wrote:
> 
> Hello!  I finally got the Aero Ektar f2.5 178mm lens up and working on
> my 4x5 inch box camera that I made.  I had an aluminum plate machined
> to the thread of the lens, so it provides fine focus adjustment.  I
> had considered using knife edge focusing by exposing a razor blade on
> a film, and drilling a hole through a cheap 4x5 holder and looking
> through the back, but instead, I used a Hartman mask to find focus
> under red, blue, green, and yellow.
> 
> 
> 
> I have been using TMax 400 film, and developing it in TMax RS.  The
> Sagitarius star cloud looks good.  I pushed the development to an ISO
> of 3200 according to the TMax RS directions.  No grain visible!
> 
> 
> 
> However, the lens appears to have quite a bit of coma at f2.5, so I’ll
> have to stop it down.  Too bad, though to be expected with a WW2
> surplus lens.
> 
> 
> 
> Once I find the best f-stop, I’d eventually like to try some color
> instead of B&W filter work, but none of the camera stores here in my
> small Australian outback town here can do anything with 4x5s – B&W or
> color.
> 
> 
> 
> I’ll post some of the results when I get something worthwhile.  Best
> regards.
> 
> 
> 
> Mike
> 
> 
> 
> 
> 
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