I wrote that I had tested Kodachrome II film,(ASA 25) in 1963. The
results indicated the resolution as being 56+ line pairs per mm.
Bill G. replied on 8/30/10, at 6:46 PM. the following:

>> This entire discussion is moot.... the number of variables involved
>> are so many, the results are only useful on a comparative basis if all
>> the details were known, Final contrast of target on film, contrast of
>> targets, color of targets, front lit or back lit targets, MTF of
>> camera lens used, MTF of inspection device, visual acuity of the
>> person inspecting the film, etc. etc.

The resolution results were established with the aid of a 100X micro-
scope. The targets were B+W engravings made by the National Bureau of
Standards, in 1952. Being as the The resolution test was performed as
directed by the NBS, all of the results should be comparative. The NBS
resolution test instructions did not mention MTF !

I was not aware that MTF ratings of camera lenses and or microscopes
were published in 1963. The U of W was not capable determining the MTF
of optical instruments in 1963.

The NBS instructions did not include any mention of the above,"details",
suggested by Bill.

--------------------

Bill wrote:

Both the lens fl and the lens to subject distance are critical.
The nominal fl values on the lenses are not relevant as they are
rarely accurate. My only point is, many film tests were flawed
as the target size on film was never accurate to start with.
How can you justify your use of the words, "rarely accurate",
"never accurate"?

Regards,

DON

> I was not aware that MTF ratings of camera lenses and or microscopes
> were published in 1963. The U of W was not capable determining the MTF
> of optical instruments in 1963.
>
> The NBS instructions did not include any mention of the above,"details",
> suggested by Bill.

Don, not sure how this thread moved to this forum...but, as I wrote
previously, and I will repeat ....


I am fully confident all the film tests performed by you and Dr. Higgs in 1963 are 100%
accurate. I am sure they are well documented and would pass any and all scientific
scrutiny of their era, as well as, any and all scientific scrutiny of today.

What more do you want?