Noblex 150 resolution at infinity

I found a useful online calculator so that I could calculate the
Noblex 150 resolution at infinity. It is here
http://www.tawbaware.com/maxlyons/calc.htm

The way I am using it is to alter the circle of confusion size until
infinity is just lost out of the depth of field. I then take the
inverse of the circle of confusion diameter to give the resolution in
line pairs per unit at infinity.

Assuming the Noblex has a 50.75mm lens and it is fixed focussed to
10.4 meters then the following is what I got for the resolution at
infinity in line pairs per millimeter.

f4.5 CoC=0.0553mm (18 lp/mm)
f5.6 CoC=0.0444mm (22.5 lp/mm)
f8 CoC=0.0311mm (32 lp/mm)
f11 CoC=0.0227mm (44 lp/mm)
f16 CoC=0.0155mm (64.5 lp/mm)

My own conclusions are that if I were to use it for distant scenes, in
preference to my Horizon 202, then I would opt to use it at f11 or
smaller. At f16 it should theoretically give spectacular results.

"RolandRB" wrote in message
om...
I found a useful online calculator so that I could calculate the
Noblex 150 resolution at infinity. It is here
http://www.tawbaware.com/maxlyons/calc.htm

Wow! With that link you don't have to worry about manufacturing variations,
lens quality, and all that stuff that requires getting off your ass to truly
determine.

What does a theoretical picture look like?

"RolandRB" wrote in message
om...
I found a useful online calculator so that I could calculate the
Noblex 150 resolution at infinity. It is here

f4.5 CoC=0.0553mm (18 lp/mm)
f5.6 CoC=0.0444mm (22.5 lp/mm)
f8 CoC=0.0311mm (32 lp/mm)
f11 CoC=0.0227mm (44 lp/mm)
f16 CoC=0.0155mm (64.5 lp/mm)

That's so strange, Roland. Why are you changing the CoC with each aperture?
You should get sharper results wide open. I mean, this IS theoretical,
right?

"jjs" wrote in message
...

"RolandRB" wrote in message
om...
I found a useful online calculator so that I could calculate the
Noblex 150 resolution at infinity. It is here

f4.5 CoC=0.0553mm (18 lp/mm)
f5.6 CoC=0.0444mm (22.5 lp/mm)
f8 CoC=0.0311mm (32 lp/mm)
f11 CoC=0.0227mm (44 lp/mm)
f16 CoC=0.0155mm (64.5 lp/mm)

That's so strange, Roland. Why are you changing the CoC with each
aperture?
You should get sharper results wide open. I mean, this IS theoretical,
right?

He's not changing the CoC, he's changing the aperture and _back calculating_
the CoC for a point at infinity from the aperture and the focus setting.
(That is, he's calculating the smallest CoC that will give a hyperfocal
distance of 10.5 feet for each f stop.)

That tells you how sharp the image at infinity will be for each f stop.

David J. Littleboy
Tokyo, Japan

Hi

Yes, your calculations seem correct. A perfect in focus lens with give about
2000 l/mm center resolution at f-1 in noon summer sun. At f-2 1000l/mm and at
f-4 500 l/mm and so on.

So the table will look like this

f-1 =2000 l/mm
f-2 =1000
f-4 =500
f-8 = 250
f-16 =125
f-32 = 64

So your 64 l/mm at f-16 is a good figure since the image still is not in
perfect focus at infinity. Although, the true system resolution on the film
after exposure will be about half that or 32 l/mm.

Standard calculation will be lens reso times film reso over lens reso plus film
reso

(64x64)
(64+64) = 32

Larry

"jjs" wrote in message ...
"RolandRB" wrote in message
om...
I found a useful online calculator so that I could calculate the
Noblex 150 resolution at infinity. It is here
http://www.tawbaware.com/maxlyons/calc.htm

Wow! With that link you don't have to worry about manufacturing variations,
lens quality, and all that stuff that requires getting off your ass to truly
determine.

What does a theoretical picture look like?

I can see you are getting interested in this side of photography. )

RolandRB wrote:



f4.5 CoC=0.0553mm (18 lp/mm)
f5.6 CoC=0.0444mm (22.5 lp/mm)
f8 CoC=0.0311mm (32 lp/mm)
f11 CoC=0.0227mm (44 lp/mm)
f16 CoC=0.0155mm (64.5 lp/mm)

My own conclusions are that if I were to use it for distant scenes, in
preference to my Horizon 202, then I would opt to use it at f11 or
smaller. At f16 it should theoretically give spectacular results.

Of a theoretical subject using the theoretical lens on this theoretical
camera you say you'e owned for years but never have used... Me, I'd go
outside and take some pictures with it and see what they look like but I
guess that's being silly!

--

Stacey

Stacey wrote:

Me, I'd go outside and take some pictures with it and see what
they look like but I guess that's being silly!

He owns it only theoretically.

Ralf

--
Ralf R. Radermacher - DL9KCG - Köln/Cologne, Germany
private homepage: http://www.fotoralf.de
manual cameras and photo galleries - updated March 30, 2004
Contarex - Kiev 60 - Horizon 202 - P6 mount lenses

"jjs" wrote in message ...
"RolandRB" wrote in message
om...
I found a useful online calculator so that I could calculate the
Noblex 150 resolution at infinity. It is here

f4.5 CoC=0.0553mm (18 lp/mm)
f5.6 CoC=0.0444mm (22.5 lp/mm)
f8 CoC=0.0311mm (32 lp/mm)
f11 CoC=0.0227mm (44 lp/mm)
f16 CoC=0.0155mm (64.5 lp/mm)

That's so strange, Roland. Why are you changing the CoC with each aperture?
You should get sharper results wide open. I mean, this IS theoretical,
right?

The lens is (assumed to be) fixed focussed to 10.4 meters and will
have a depth of field that depends on what the acceptable circle of
confusion diameter is. So if I play around with the value of the
circle of confusion diameter then I can set it to a value where
infinity is only just squeezed out of the depth of field. Once I have
this value with infinity just out but very nearly in then the inverse
of it will give me the highest possible resolution in line pairs per
millimeter at infinity. I am working the formula backwards to find out
how sharp the image could be for infinity scenes.

What it means is no matter how sharp the lens is at 10.4 meters then
the highest achievable resolution at infinity for f4.5 is 18 lp/mm and
at f5.6 the highest resolution achievable is 22.5 lp/mm and so on as
listed.

(Hemi4268) wrote in message ...
Hi

Yes, your calculations seem correct. A perfect in focus lens with give about
2000 l/mm center resolution at f-1 in noon summer sun. At f-2 1000l/mm and at
f-4 500 l/mm and so on.

So the table will look like this

f-1 =2000 l/mm
f-2 =1000
f-4 =500
f-8 = 250
f-16 =125
f-32 = 64

So your 64 l/mm at f-16 is a good figure since the image still is not in
perfect focus at infinity. Although, the true system resolution on the film
after exposure will be about half that or 32 l/mm.

Standard calculation will be lens reso times film reso over lens reso plus film
reso

(64x64)
(64+64) = 32

Larry

I am always happy to read any of your posts because of your past
experience with lenses. Thanks for the list of resolutions for a
perfect lens. No lens is perfect, of course. I remember you once
posted a similar list for typical brand name lenses. Could you post
that here again please and let us know where the figures came from. I
think people easily confuse lens resolution with practical on-film
resolution. Since film resolution can vary then I think it is best to
keep lens resolution and film resolution as seperate topics and get
the effective on-film value by combining them using the formula you
quoted above.

Once I have the list of resolutions for typical brand-name lenses I
will do a comparison between the Horizon 202 fix-focussed at infinity
compared with a Noblex 150 fix-focussed at 10.4 meters for
photographing distant (effectively at infinity) scenes.