Newsgroup: it.arti.fotografia
Titolo: Pellicola

Provate a dare un'occhiata a questo sito (purtroppo in tedesco, però le foto
sono esplicative):
http://www.gigabitfilm.de/html/deutsch/bildbeispiele.htm
Ho trovato l'indirizzo su rec.photo.darkroom e si discute di questa novità con
un po' di diffidenza. Effettivamente nemmeno io ci credo al 100%.
Che ne dite?
Elia Freddi

 ha scritto nel messaggio
news:3a3f7a73...@news.iunet.it...

 ha scritto nel messaggio
news:3a3f7a73...@news.iunet.it...


gli argomenti trattati?
Prova ad andare su 
http://translator.go.com
 ed immettere la url della
pagina 
http://www.gigabitfilm.de/html/deutsch/produkte.htm
Quello che viene fuori non sarà perfetto, ma è comprensibile.
Purtroppo si può tradurre solo dal tedesco all'inglese. Bisognerebbe
trovare un traduttore che traduce direttamente dal tedesco
all'italiano. Oppure puoi provare dare di nuovo in pasto al traduttore
automatico i risultati della prima versione facendogli stavolta
tradurre da inglese a italiano. Purtroppo pare non si possa fare in
modo automatico.
Ciao, Diego.


Purtroppo non conosco il tedesco.
Su rec.photo.darkroom c'è un post in cui è riportata la traduzione in inglese
del datasheet, provo a cercare l'autore per chiedere l'autorizzazione per
postarlo.
Riassumendo brevemente risulta che la pellicola è 40 ISO, ha una risoluzione di
720 linee/mm con contrasto 1:1000 (decisamente molto più alto della technical
pan), supporto in poliestere, è pancromatica però con la sensibilità nel rosso
un po' ridotta. Lo sviluppo deve essere fatto con i chimici della casa
produttrice però dal poco che riesco a capire è piuttosto critico in quanto
molto sensibile alla pulizia del tank, al volume del tank stesso, addirittura al
volume di aria presente nel tank (!!!!!!!), il fissaggio è estremamente rapido
(20 secondi!!!).
Interessante il commento in cui si consiglia di non scattare foto con F:8 o
aperture inferiori (quindi non meno di F:5.6) in quanto l'immagine perde in
qualità per effetto della difrazione della luce (!!!!!!!!!!!!!!!!!!!!). 
Ciao
Elia Freddi

è una Velvia in versione B/N !
Da come spesso vedo, la fotografia chimica ha molto ancora da dare e strada
da percorrere, tanto che quella digitale avrà sempre un po' di affanno a
starle dietro, questo non può essere che un bene per tutti.
--
Gelatina
_______________________________________


 wrote in message
3a3f7a73...@news.iunet.it...



Si tratta di una pellicola con risoluzione almeno due volte migliore della
technical pan. A volte io mi stupisco ancora.
Ciao
Elia Freddi

 technical pan. A volte io mi stupisco ancora.
Quello che ottengo io con una TMX e la mia Leica ?
--
Phil O'Sophy || Filippo M. Caroti
e-mail:



Molto di più.
Ciao
Elia Freddi

Questa è la traduzione in inglese fatta da Q. G. de Bakker (mi ha concesso di
pubblicarla sul ng) delle informazioni tecniche relative a questa pellicola.
Vedete un po' voi.
Ciao
Elia Freddi
***************************************************************************
Provisional Datasheet Gigabit ISO 40 135 mm film. (as per 16th July 2000)
Data only valid in conjunction with Gigabitfilmchemicals and prototype ISO 40
Gigabit 135 mm film.
Gigabitfilm GmbH, H. Böll Str. 17, 52372 Kreuzau, Fax: 02422/500460
Filmmaterial: Silverhalogenid
Filmbase: Polyester (PET=Polyethylenterephtalat), can be cut with
siccors only (Don't forget to bring siccors into the darkroom!)
Colour sensitivity: panchromatic, slightly reduced red-sensitive
compared to "normal" panchromatic film.
Resolution: Contrast 1:1000  720 Linepairs/mm
Granularity: very low, low at high densities
Processing: processing must be done in clean tanks. Tanks may not
contain any residue of wetting agents.
Development: dilute Gigabitfilm chemicals 1+9. 250 ccm solution at
working strength must be used to develop 1 135/36 film at 20°C. We recommend for
a first test 6 minutes development for gamma 0.5-0.6,
(gradation/temperature [possible temperatures ranging up to 26°C]/developingtime
curves will be published, pending assessment of the production batch of the
emulsion).
Agitation at 20 second intervals.
Gigabitfilm chemicals are free from all formation of artefacts or schlieren,
even at insufficient agitation. Some users however did find occasional
problems, making us believe they were caused by the equipment used.
The chemicals are intended to be used in 250 ml tanks. To use inversion
agitation, the usual "headroom" in these tanks when filled with
chemicals and reel is sufficient. This "headroom" volume should be about 60 ml,
up to a maximum of 100 ml, of air. There are many tanks available, meant to
take 250 ml of liquids to process 1 film, that however have a headroom of way
in excess of 100 ml. When these tanks are inverted, as per instructions of
their manufacturer, the film is completely free, drained from processing
chemicals.
This means that the type of agitation given using these tanks is more like
rotational agitation than inversion. This is why we give the express
recommendation for our provisional Gigabitfilmchemicals: not suited for rotation
development.
If you find yourself having tanks with a too large headroom, you can
make do by diluting the chemicals more. But first measure the headroom of your
particular tank: fill your tank completely (including the volume in the lid).
Then subtract the 60 to 100 ml neede for the pocket of air that is
required to agitate the chemicals during inversion.
The chemicals can be diluted to 1+16. Depending on the cycle of agitation,
first test should start with approximately 12 minutes of development.
Rotation-development: not recommended. Suitable chemicals are under development
Stopping: rinse during 5 seconds in running water.
Fixing: normal rapid-fixing baths, approx. 10-20 seconds, (yes: ten to
twenty seconds! The crystals in Gigabit films are much smaller than in
other, "normal" films. Look at it this way: if you would put large crystals
of sugar-candy in your tea, it takes a very long tme for these to dissolve.
Fine sugar dissolves instantly.). If you fix Gigabit film too long (over
2-3 minutes), depending on the fixer used, densities in the shadow areas can
be reduced.
See how extremely fast Gigabit film is fixed by putting a small piece of Gigabit
film (a piece of the filmleader) into a fixing bath. Any remaining colouring is
due to the antihalation backing, and will be removed in the alkaline developer.
Using Gigabit films the usual rule applies: fixing time is three times the
clearing time.
Washing: for normal purposes: 30 seconds to 2 minutes. for archival purposes: at
least 5 minutes, certified data will be published
Developing in large tanks (over 250 ccm): data will be published
Drying: we recommend a final washing in distilled water, for instance by
spraying the film with distilled water after it has been put up to dry. As an
alternative, normal kitchen paper towels (fresh) can be used, folded over
several times, finally folded in an U-shape. Put the film in between the
U-shaped towel, keeping the paper taut so the film will be touched by the
tension of the paper only, and slowly move the paper along the film, downwards.
The film will be dry in 2 to 4 minutes.
Attention: the film will appear to be much clearer when wet. Only after full
drying will the correct density (especially in the shadow areas) be visible.
Enlarging: a special backing and the typical minimal density of the Gigabit film
will minimize problems with dust and ensure easy enlarging.
Enlarger and optics: if a negative carrier with glass is used, at least the
lower glass must be removed. If not, all available enlarger lenses will show
a considerable reduction in MTF values. A suitable, precision glassless negative
carrier is highly recommended. The aperture of the enlarger lens should not be
stopped down beyond f/5.6.
Taking lens: on the quality of photographic lenses: a hotly debated item
concerning the Gigabit film. Because of diffraction, you should try not to stop
your lens down beyond f/5.6. Many camera lenses are still designed to
give better contrast. It is our opinion that this emphasis on contrast
considerably reduces resolution. Yet many available lenses actually do have
a resolution of 350 line pairs/mm in the final print. 
Flatness: most 35 mm cameras unwind the film in a straight path. With the
filmcartridge on the left, the film is wound in an anti-clockwise manner on
the right (seen from above and behind). This type of camera did give a good
result, when using film having the tough PET base. Cameras having a vacuum
back of course should be preferred, yet conventional cameras can give
extraordinary results. If the film is wound in the other direction,
tension could build up in the film, and asymmetrical distortions of the film in
the film channel can occur.
Autofocuscameras function perfect, facing the hightened demands put on
sharpness, but only as long as they still have the original manufacturers
adjustement. Samples have shown that cameras readjusted by repairshops
show considerable tolerances.
Filmtransport: occasionally, premature automatic filmrewind was triggered in
cameras having this feature after only 24-30 exposures. This most likely is
caused by the tough PET filmbase. The advantages of the PET base however
outweigh any such mishaps. A 135/24 confection is being considered.
Flash: please extend development by 10%!
Cameras having TTL and TTL-flashmetering: cameras having off the film
TTL-metering must compensate for the higher reflectivity of the Gigabit
emulsion. The compensation needed may be as high as 2½ stops.
Focussing screen: samples show that there are variances in the focussing
precision in many cameras, both due to the position of the focussing screen
and to the split-image rangefinder. If you get poor results please check your
equipment. The same is true concerning the often too short inifinity
setting of lenses.
Risks: the only risk after more than ten years of testing: the high dynamic
range of the Gigabit ISO 40 film tempts to be too carefree when determining
correct exposure. This is no problem, the film is suited for such an approach.
However, demanding photographers will notice an increase in granularity in the
highlights. Grain will still be much finer than in normal film, but this
increase in grain can be avoided by a more careful way of working.
Side effects: in processing, an increased forming of froth can be observed
near the end of development. This is not a problem, and is due to normal,
slight tolerances in the amount of wetting agent added during production of
the emulsion.
Unkown risks: should you notice anything unusual, please inform us, giving
all details, so we can help others prevent making the same mistakes.
Psychological risks: marketing studies have shown that our testers over the
age of 25 years, following the first week of trying our film, are faced with
the dilemma of having to consider their lifes work up to the point they first
tried Gigabit film, their complete archives, as totally worthless. In all
these cases unusual psychological reactions, ranging from active amnesia to
severe headaches, are exhibited. This indication may serve as an advise to
all future Gigabit users over 25 years of age to appraoch trying the Gigabit
film with all due care, and not to rush things, yet proceed with determination.
After all you are only as old as young as you feel.

Elia Freddi wrote:

    Ciao,
capisco bene i tuoi dubbi. Guarda l'ingrandimento 1000x delle due ragazzine sulla
terrazza: la pellicola potrà essere anche una bomba, ma mi devi dire quale
obiettivo al mondo può avere una risoluzione di (almeno) 1000 righe per
millimetro. E nessuno se ne esca con frasi tipo "eh, ma usavano obiettivi
Leica...:-)".
    E' semplicemente una bufala!
Marco