MF & Technical Pan, looking for optimum sharpness

Hello,

The last few weeks I've been shooting landscapes with a Hasselblad 503CW,
using a CFE 2.8/80 mm- lens and TMX. Now that I've finally decided on how to
build my compositions, I'm considering to start all over again using
Technical Pan. For most pictures, the lens is stopped down to f11 or more.

As you probably suspect from the combination medium-format / Technical Pan,
I'll be trying to get the most out of my camera/film combination in terms of
detail, sharpness, ...

The technical data-sheet of my lens states that Depth Of Field data are
'calculated for a blur circle of 60 µm and do nog include the effect of lens
aberrations. For very critical photography and great enlargements this blur
will be visible.'
(http://www.hasselblad.se/Archive/doc...oductsheets/CF
E80.pdf). Further ause of DOF-data for apertures of 2 f-stops larger is
suggested.

Kodak claims that ther Technical Pan film
(http://www.kodak.com/global/en/profe...p255/p255.jhtm
l?id=0.1.18.14.21.22.16&lc=en) has an RMS-granularity of 5 (developed in
Technidol, of which I have a few bottles craving for film in the darkroom).
As far as I can figure out, the RMS-granularity is a standard deviation
(been confronted with rms-values more then a few times throughout my
education), but I don't know of what. There must be a link to the size of
film-grain, but to me it's still a missing link.

My question is not so much wether, for my specific case, I should take in
account the 2-stop correction for DOF-data Hasselblad recommends. Most of
all I would like to understand why (of maybe why not) I should consider this
correction.

Thx to all (and please accept my excuses for cross-posting),

Philippe

"Philippe Lauwers" schreef in bericht
i.nl...
Hello,

The last few weeks I've been shooting landscapes with a Hasselblad 503CW,
using a CFE 2.8/80 mm- lens and TMX. Now that I've finally decided on how
to
build my compositions, I'm considering to start all over again using
Technical Pan. For most pictures, the lens is stopped down to f11 or more.

As you probably suspect from the combination medium-format / Technical
Pan,
I'll be trying to get the most out of my camera/film combination in terms
of
detail, sharpness, ...

The technical data-sheet of my lens states that Depth Of Field data are
'calculated for a blur circle of 60 µm and do nog include the effect of
lens
aberrations. For very critical photography and great enlargements this
blur
will be visible.'

(http://www.hasselblad.se/Archive/doc...oductsheets/CF
E80.pdf). Further ause of DOF-data for apertures of 2 f-stops larger is
suggested.

Kodak claims that ther Technical Pan film

(http://www.kodak.com/global/en/profe...p255/p255.jhtm
l?id=0.1.18.14.21.22.16&lc=en) has an RMS-granularity of 5 (developed in
Technidol, of which I have a few bottles craving for film in the
darkroom).
As far as I can figure out, the RMS-granularity is a standard deviation
(been confronted with rms-values more then a few times throughout my
education), but I don't know of what. There must be a link to the size of
film-grain, but to me it's still a missing link.

My question is not so much wether, for my specific case, I should take in
account the 2-stop correction for DOF-data Hasselblad recommends. Most of
all I would like to understand why (of maybe why not) I should consider
this
correction.

Thx to all (and please accept my excuses for cross-posting),

Philippe




Some more thoughts ... my intuition tells me that, as long as this blur
circle is smaller than the average silver-particle in the film used, the
piece of the image can be considered as 'sharp'.
Is there a relationship between the RMS-granularity and the size of
silver-particles in the emulsion (I suppose so, but don't have a clue on
what this law could be) ? Is there a rule of thumb that gives an estimation
for the grain-size based on RMS-granularity ? Are there any other elements
that I should consider ?

"Philippe Lauwers" wrote

Hasselblad 503CW ... CFE 2.8/80 ... Technical Pan ... get the most

Shoot at optimum aperture, about f5.6.
Use a 25A filter.
Use a tripod (goes without saying).

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/

"Philippe Lauwers" wrote in message
i.nl...
Hello,

The last few weeks I've been shooting landscapes with a Hasselblad 503CW,
using a CFE 2.8/80 mm- lens and TMX. Now that I've finally decided on how
to
build my compositions, I'm considering to start all over again using
Technical Pan. For most pictures, the lens is stopped down to f11 or more.

As you probably suspect from the combination medium-format / Technical
Pan,
I'll be trying to get the most out of my camera/film combination in terms
of
detail, sharpness, ...

I'm not convinced it's all that much better than Provia or Velvia 100F.
Maybe slightly. It scans really ugly (gritty) and dust is really obnoxious.
YMMV if you are projection printing.

But it's very much worth the time experimenting.

The technical data-sheet of my lens states that Depth Of Field data are
'calculated for a blur circle of 60 µm and do nog include the effect of
lens
aberrations. For very critical photography and great enlargements this
blur
will be visible.'

(http://www.hasselblad.se/Archive/doc...oductsheets/CF
E80.pdf). Further ause of DOF-data for apertures of 2 f-stops larger is
suggested.

My experience is that hyperfocal focusing is usually a bad idea: any loss of
sharpness at infinity hurts. For landscapes, leave your lens at infinity
focus except in rare cases.

Remember that DOF tables were all created in the days when medium format was
the format used by the masses for snapshots and small prints. Things are
different in this day of 4000 dpi scans and 13x19s from 645. Even two stops
may not be enough. With my 35/3.5 lens on my Mamiya 645, I get lots of DOF.
The DOF on all my other lenses (55, 110, 150) is esssentially zero for
practical purposes.

Kodak claims that ther Technical Pan film

(http://www.kodak.com/global/en/profe...p255/p255.jhtm
l?id=0.1.18.14.21.22.16&lc=en) has an RMS-granularity of 5 (developed in
Technidol, of which I have a few bottles craving for film in the
darkroom).
As far as I can figure out, the RMS-granularity is a standard deviation
(been confronted with rms-values more then a few times throughout my
education), but I don't know of what. There must be a link to the size of
film-grain, but to me it's still a missing link.

Stop thinking and go shoot some frames.

My question is not so much wether, for my specific case, I should take in
account the 2-stop correction for DOF-data Hasselblad recommends. Most of
all I would like to understand why (of maybe why not) I should consider
this
correction.

See above. It's your art and your eye: decide for yourself.

David J. Littleboy
Tokyo, Japan

In article , "Philippe
Lauwers" wrote:

My question is not so much wether, for my specific case, I should take in
account the 2-stop correction for DOF-data Hasselblad recommends. Most of
all I would like to understand why (of maybe why not) I should consider this
correction.

Hasselblad's article seems to make it clear: when closely scrutinizing the
outcome or making large prints, the hyperfocal table does not work because
it presumes a modest enlargement - a generous COC. Big prints or more
strident standards requires a smaller COC.

Benchracers. Sheesh.

In rec.photo.darkroom Philippe Lauwers wrote:
Hello,

The last few weeks I've been shooting landscapes with a Hasselblad 503CW,
using a CFE 2.8/80 mm- lens and TMX. Now that I've finally decided on how to
build my compositions, I'm considering to start all over again using
Technical Pan. For most pictures, the lens is stopped down to f11 or more.

My experience with Techpan is that it's very fine grain, but not optimum sharpness.

There is a thing like "visible sharpness", and this isn't reflected in RMS
values. I ususally shoot Delta 100 in medium format (mostly SL66 and Mamiya 7)
and occasionally use Efke 25 in Beutler developer. These two films give
very good visible sharpness, my test films with Techpan and Neofin Doku
had finer grain, but less sharpness. Both cameras were used with a
large Linhof tripod and MLU at the SL66. Both Delta 100 and Efke 25 are
good enough for enlargements to 1mx1m, and even then smallest details
of 1mm are easily visible. Good enough for me, if I want more, I use 13x18.

Martin

"Philippe Lauwers" wrote

'calculated for a blur circle of 60 µm and do nog include the
effect of lens aberrations. For very critical photography and great
enlargements this blur will be visible.

You might look at it this way. Tech Pan is for two dimensional
subjects. That was the reason for it's creation. No three dimensional
subject will do Tech Pan justice.
Minox and 35mm users love the stuff because big grainless
enlargements can be made. With a very carefull selection of subject
and superb optics they can produce large sharp prints. Dan

"Martin Jangowski" wrote in message
...

My experience with Techpan is that it's very fine grain, but not optimum
sharpness.

There is a thing like "visible sharpness", and this isn't reflected in RMS
[...]

I have the very same notion. Apparent ("visible") sharpness is made via edge
effects, and a very fine, smooth grain isn't likely to have ot. "Creamy" is
how I describe many fine-grain films. It's good, or not, depending on your
likes. Oof the reasons I just friggin hate Kodak's T-Grain films is because
it is the worst combination of 'kinda' fine grain without a chance of edge
sharpness.

Use a tripod (goes without saying).

a what ? ;-) (grin)

"Philippe Lauwers" wrote:

Use a tripod (goes without saying).

a what ? ;-) (grin)

One of these: http://www.pbase.com/image/26582234/large (Oops)

David J. Littleboy
Tokyo, Japan