Optimum Aperture for 150mm G-Claron?????

(Mike) wrote in message .. .
I use my 150G on both 4x5 and 5x7. Great lens, lightweight with a
goodly amount of coverage. I generally use this lens at f22 and more
than pleased with the results.

- Mike


And this is using the lens up close?

I wonder why my f16 pics turned out so fuzzy...the lens looked
perfectly good. I think i might rent it again and look a bit closer.


S.

Both close for still life and at infinity for landscapes. For outdoor
work I found a lens shade to be beneficial. I found a 35.5 to 49mm
step up ring and used a rubber lenshood for a 50mm lens.

By the way, the step up ring is a good investment for this lens so you
can mount filters, lens cap etc


- Mike


On 13 Feb 2004 13:23:07 -0800, (Dr. Slick) wrote:

(Mike) wrote in message .. .
I use my 150G on both 4x5 and 5x7. Great lens, lightweight with a
goodly amount of coverage. I generally use this lens at f22 and more
than pleased with the results.

- Mike


And this is using the lens up close?

I wonder why my f16 pics turned out so fuzzy...the lens looked
perfectly good. I think i might rent it again and look a bit closer.


S.

How does this file say that the sharpest aperture is f22?

I rented this lens and shutter, and took pics at f16, they turned
out terribly fuzzy. So if f22 is the optimum, i find it hard to
believe that one f-stop away could look so bad. Someone at K and S
said that you have to stop way down to f45 with this lens. Maybe so?

It's not the lens (presuming it's working correctly) - you should not be
getting "terribly fuzzy" pix using it at f16 - it will work just fine at f16
at 1:1 or infinity. It's either the setup, focus, vibration, mismounting of
the lens or a lens malfunction. I've used this and other G-Claron lenses for
museum/artwork copy work with no problem. Sometimes (due to certain
expediencies) at f11, though usually at f22/32. Using it at f16 wasn't what
caused your problem. (I've also used them for plenty of landscape/urban
landscape work on 4x5 and 8x10, at all sorts of apertures)

also:

Depends on the magnification. At 1:1 probably f11, at infinity focus
it really does not get sharp until f22 and f32

is pretty much bunkum - as is the whole "flat field" lens mythology. Best
debunking of all that is a paper on Wisners site

I agree, I think there's much too much emphasis here on the optimum range
and aperture of the lens. All lenses are optimized for some magnification or
magnification range. My APO Symmar 210mm lens is optimized ror 1:10 to
infinity I believe but I use it all the time at closer ranges without giving
it a thought. I also have used my two G Claron lenses at all sorts of
different magnificiation ratios and they seem to produce excellent results
at all ranges.

With all lenses I select the aperture on the basis of what is needed to
obtain the desired depth of field and no more, not on the basis of what the
lens designer says is the "optimum" aperture. I think that insufficient
depth of field from too wide an aperture, or probably even the effects of
diffraction from too small an aperture, will be more apparent in a print
than will failure to use the theorietical "optimum" aperture.

wrote in message
.. .

How does this file say that the sharpest aperture is f22?

I rented this lens and shutter, and took pics at f16, they turned
out terribly fuzzy. So if f22 is the optimum, i find it hard to
believe that one f-stop away could look so bad. Someone at K and S
said that you have to stop way down to f45 with this lens. Maybe so?

It's not the lens (presuming it's working correctly) - you should not be
getting "terribly fuzzy" pix using it at f16 - it will work just fine at
f16
at 1:1 or infinity. It's either the setup, focus, vibration, mismounting
of
the lens or a lens malfunction. I've used this and other G-Claron lenses
for
museum/artwork copy work with no problem. Sometimes (due to certain
expediencies) at f11, though usually at f22/32. Using it at f16 wasn't
what
caused your problem. (I've also used them for plenty of landscape/urban
landscape work on 4x5 and 8x10, at all sorts of apertures)

also:

Depends on the magnification. At 1:1 probably f11, at infinity focus
it really does not get sharp until f22 and f32

is pretty much bunkum - as is the whole "flat field" lens mythology. Best
debunking of all that is a paper on Wisners site

Dr. S,

My answer may have sounded too negative. If I were doing the job for
the paintings that is the lens I would choose (unless you have
infinite $ and can afford a large format macro-copy lens.)


Just out of curiousity, what sort of large format macro-copy
lenses could you or anyone else recommend?
The 4 element Apos G-Claron, Apo Ronar, Apo Artar all need a focal length of
210mm (as do Micro Nikors they are 6 not 4 element) to cover 4x5 without fall
off (180 may do but 210 is a much more common focal length. The newer Apo
lenses The Apo Symmar or Apo Sironar will cover 4x5 at infinity, but I don't
know if these are flat field. But then again any tessar formula lens of 180mm
or above should give you the pics you need.



This lens
design is pretty forgiving of being slightly outside the design range.
I have several G-clarons and they are superb lenses. You just have
to stop them down to f22 at infinity focus (landscapes outside), you
will not be at infinity for the paintings. Go ahead and try one.
There are lots of process lenses out there too that would work but
they don't have shutters.

Kirk

Like i said, if f22 is the sweet spot up close, i find it hard
to believe that my f16 pics turned out so blurry.

I'm using a 210mm G_Claron that I got off a graphics camera, mounted it on a
Ysarex shutter from a Polaroid MP-3, and the sharpness at f11-32 is fine
copying art work. How are you focusing? I have to admit I never try to focus
stoped down. When I had an 8x10 I screwed up a lot of film trying to get a
good focus stopped down, too much depth of field, so I focus wide open, stop
down check alignment. I understand that many older lenses had substatial focus
shift when stopping down, just have avoided those lenses. Just wondering if
you are trying too hard.

Tom

(Tom Monego) wrote in message news:1uNYb.9293$Dc2.3094@lakeread01...



Like i said, if f22 is the sweet spot up close, i find it hard
to believe that my f16 pics turned out so blurry.

I'm using a 210mm G_Claron that I got off a graphics camera, mounted it on a
Ysarex shutter from a Polaroid MP-3, and the sharpness at f11-32 is fine
copying art work. How are you focusing? I have to admit I never try to focus
stoped down. When I had an 8x10 I screwed up a lot of film trying to get a
good focus stopped down, too much depth of field, so I focus wide open, stop
down check alignment. I understand that many older lenses had substatial focus
shift when stopping down, just have avoided those lenses. Just wondering if
you are trying too hard.


That was the first piece of advice i got from the seller, always
focus at the widest aperture, then stop down. I don't think the
G-Claron had a focus shift, and at any rate, the isn't really enough
light to do this at f16, at least not with my lighting.


S.

: (Tom Monego)

The 4 element Apos G-Claron, Apo Ronar, Apo Artar

The G-Claron is a 6 element lens. Stopped down to f45 a 150 will cover 5x7 at
infinity and beyond.
Chuck

In article ,
says...

: (Tom Monego)

The 4 element Apos G-Claron, Apo Ronar, Apo Artar

The G-Claron is a 6 element lens. Stopped down to f45 a 150 will cover 5x7 at
infinity and beyond.
Chuck


Always thought the G-Claron was an Artar formula, one of the more elegant
designs for older lenses. 5x7 at f45 at 1:1 possible not infinity though, my
210 G-Claron gives me some movements but has a definite limit on 4x5. This is a
repro camera lens, thew one I have is off an old stat camera never used for
anything but kodaliths, a very nice lens. I'll check the Schneider web site
though I could be wrong about the formula.

Tom

Always thought the G-Claron was an Artar formula, one of the more elegant
designs for older lenses. 5x7 at f45 at 1:1 possible not infinity though,
my
210 G-Claron gives me some movements but has a definite limit on 4x5. This
is a
repro camera lens, thew one I have is off an old stat camera never used
for
anything but kodaliths, a very nice lens. I'll check the Schneider web
site
though I could be wrong about the formula.

my 210 G-Claron covered 8x10 with about 1" of rise/fall @f 22 and aboutr 1
3/4" @ f32 1/2

exactly how much movment are you lookignfor on your 4x5... and is it a
G-Claron or a Repro Claron?

Tom said:

my 210 G-Claron gives me some movements but has a definite limit on 4x5.

That's very strange. I used a 210 G Claron on 8x10 and had ample room for
movements (ample by my standards at least, possibly limited by others' but
definitely room for some movements) when stopped down to about f22 or
smaller. I used it with 8x10 mostly for exterior architecture and don't
recall having any problem with any movement limits.

"Tom Monego" wrote in message
...
In article ,
says...

: (Tom Monego)

The 4 element Apos G-Claron, Apo Ronar, Apo Artar

The G-Claron is a 6 element lens. Stopped down to f45 a 150 will cover
5x7 at
infinity and beyond.
Chuck


Always thought the G-Claron was an Artar formula, one of the more elegant
designs for older lenses. 5x7 at f45 at 1:1 possible not infinity though,
my
210 G-Claron gives me some movements but has a definite limit on 4x5. This
is a
repro camera lens, thew one I have is off an old stat camera never used
for
anything but kodaliths, a very nice lens. I'll check the Schneider web
site
though I could be wrong about the formula.

Tom