Schneider APO Artar

How about lateral color, which is a difference in image
size with color of light.

Yes this would be true and a true APO would correct for this regardless of
f-stop. It makes for easy overlap of seperation negatives. I am not sure
though that the APO correction would hold for much more the the design 1:1
scale that this lens is designed for.

Larry

How about lateral color, which is a difference in image
size with color of light.

Yes this would be true and a true APO would correct for this regardless of
f-stop. It makes for easy overlap of seperation negatives. I am not sure
though that the APO correction would hold for much more the the design 1:1
scale that this lens is designed for.

Larry

How about lateral color, which is a difference in image
size with color of light.

Yes this would be true and a true APO would correct for this regardless of
f-stop. It makes for easy overlap of seperation negatives. I am not sure
though that the APO correction would hold for much more the the design 1:1
scale that this lens is designed for.

Larry

Aside from the fact that "Errr, no...", a 350mm on 10x8 doesn't exactly
have
a _whole_ lot of DoF even at f9.

He said "depth of focus." DoF is the abbreviation for depth of field.
They're two different things.

"Bandicoot" wrote in message
...
"Hemi4268" wrote in message
...
I've got an APO Artar Schneider 360mm F9

Just about any lens will be an APO at f-9 because of the large depth of
focus
at f-9. The word APO only means something at say f-2 or even maybe f-4.


Aside from the fact that "Errr, no...", a 350mm on 10x8 doesn't exactly
have
a _whole_ lot of DoF even at f9.


Peter

Aside from the fact that "Errr, no...", a 350mm on 10x8 doesn't exactly
have
a _whole_ lot of DoF even at f9.

He said "depth of focus." DoF is the abbreviation for depth of field.
They're two different things.

"Bandicoot" wrote in message
...
"Hemi4268" wrote in message
...
I've got an APO Artar Schneider 360mm F9

Just about any lens will be an APO at f-9 because of the large depth of
focus
at f-9. The word APO only means something at say f-2 or even maybe f-4.


Aside from the fact that "Errr, no...", a 350mm on 10x8 doesn't exactly
have
a _whole_ lot of DoF even at f9.


Peter

Aside from the fact that "Errr, no...", a 350mm on 10x8 doesn't exactly
have
a _whole_ lot of DoF even at f9.

He said "depth of focus." DoF is the abbreviation for depth of field.
They're two different things.

"Bandicoot" wrote in message
...
"Hemi4268" wrote in message
...
I've got an APO Artar Schneider 360mm F9

Just about any lens will be an APO at f-9 because of the large depth of
focus
at f-9. The word APO only means something at say f-2 or even maybe f-4.


Aside from the fact that "Errr, no...", a 350mm on 10x8 doesn't exactly
have
a _whole_ lot of DoF even at f9.


Peter

(Hemi4268) wrote in message ...
How about lateral color, which is a difference in image
size with color of light.

Yes this would be true and a true APO would correct for this regardless of
f-stop. It makes for easy overlap of seperation negatives. I am not sure
though that the APO correction would hold for much more the the design 1:1
scale that this lens is designed for.

Larry

Bear in mind that any symmetrical lens is completely and automatically
corrected for lateral color at 1:1 (along with distortion and coma).
This is true even if the lens is not corected for primary axial color.

Brian
www.caldwellphotographic.com

(Hemi4268) wrote in message ...
I've got an APO Artar Schneider 360mm F9

Just about any lens will be an APO at f-9 because of the large depth of focus
at f-9. The word APO only means something at say f-2 or even maybe f-4.

Larry

Apochromatic correction requires at least three crossings in the
longitudinal color curve, and has nothing to do with f/#. True
apochromatic correction is a big deal in the realm of refracting
telescope objectives, where f/9 is considered *fast*. Sadly, in the
field of photography, manufacturers like Schneider and Rodenstock have
perverted and dumbed-down the word "apochromatic" to suit their own
selfish ends.

Brian
www.caldwellphotographic.com

Hi

Since f-stop controls the amount of depth of focus, the term APO correction
becomes less and less meaningful at smaller f-stops. Although as pointed out,
focal length differences in the main tri-color is also at a minimum which has
nothing to do with the f-stop position.

I am just trying to point out an APO lens at f-2 is far more difficult to
produce then a APO f-9 lens.

As far as telescopes, we all know that mirror telescopes by design have no
color errors "what-so-ever" and are APO by defult. That is why we see very
little glass lens telescopes except ones sold by K-mart for $99.

Larry

Hi

Since f-stop controls the amount of depth of focus, the term APO correction
becomes less and less meaningful at smaller f-stops. Although as pointed out,
focal length differences in the main tri-color is also at a minimum which has
nothing to do with the f-stop position.

I am just trying to point out an APO lens at f-2 is far more difficult to
produce then a APO f-9 lens.

As far as telescopes, we all know that mirror telescopes by design have no
color errors "what-so-ever" and are APO by defult. That is why we see very
little glass lens telescopes except ones sold by K-mart for $99.

Larry