Visualizzazione post con etichetta tecnica. Mostra tutti i post
Visualizzazione post con etichetta tecnica. Mostra tutti i post

giovedì 30 ottobre 2025

Test della moneta in camera oscura

Il "test della moneta" in camera oscura serve a verificare se la luce rossa o qualche altra fonte di luce ti vela (ingrigisce) la carta mentre la usi in camera oscura e non ti consente di ottenere bianchi brillanti sulle tue stampe...

Consiste nel posizionare una moneta al centro di un pezzetto di carta fotografica non esposto, lasciare carta e moneta tra ingranditore e bacinelle per una decina di minuti e poi sviluppare e fissare la carta normalmente: se la moneta ha lasciato un segno al centro del pezzetto di carta fotografica, significa che hai un problema con la luce rossa o ti filtra luce da qualche parte.

Procedura:
- Posiziona un pezzo di carta fotografica non esposto tra ingranditore e bacinelle.
- Appoggia una moneta al centro del pezzetto di carta fotografica non esposta.
- Lascia la moneta e la carta solo con la luce rossa per una decina di minuti (non usare l'ingranditore o lo smartphone, non spostare la moneta sul foglio). 
- Dopo il periodo di esposizione, sviluppa e fissa la carta fotografica come se dovessi stampare una foto normalmente.

Verifica:
- Se, dopo lo sviluppo e il fissaggio, la moneta ha lasciato un segno visibile al centro del pezzetto di carta, la luce rossa e' troppo forte o la camera oscura ha delle infiltrazioni di luce e il test è fallito.
- Se non si vede alcun segno, significa che l'ambiente è adatto a stampare senza ingrigire i fogli di carta.

N.B. la maggior parte delle volte la luce rossa inattitica e' troppo forte o troppo vicina all'ingranditore e alle bacinelle, oppure e' la luce dello smartphone usato mentre la carta e' nello sviluppo...

venerdì 26 settembre 2025

lunedì 2 gennaio 2023

Confronto tra Kentmere Pan 100 e Ilford fp4+

 

Interessante confronto di Alex Doran tra la nuova pellicola Kentmere Pan 100 nel formato da 120 e la Ilford fp4+... 

Pellicole scattate usando dorsi diversi sulla stessa Hasselblad e sviluppate in Rodinal 1+5 e D76 1+1... 

A corredo del video ci sono pure i link alla galleria su Flickr con le scansioni dei negativi in altissima risoluzione per una verifica personale dei risultati del confronto...

Il video su Youtube

La galleria su Flickr con le scansioni

mercoledì 5 ottobre 2022

Il problema della "neve" sulle pellicole Ilford da 120 e della loro carta protettiva

 






Riporto integralmente un post presente sul blog ufficiale della Ilford risalente al marzo del 2022 riguardo il problema della "neve" sulle pellicole da 120, causato dal contatto con la carta protettiva.

https://www.ilfordphoto.com/updated-120-roll-film-statement/

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

In March 2020 we issued a statement in relation to instances of spots / mottle affecting a small percentage of 120 roll film negatives.

The quality of our products and the satisfaction of our customers is paramount and something the ILFORD name has been built on for over 140 years. Our R&D team were tasked with resolving this issue and so we would like to update you as to what they have been up to.

With your help we have been able to more accurately track and identify instances of spots / mottle on our 120 films. Your feedback (via www.ilfordphoto.com/product-feedback) has, and continues to be, a great help in enabling us to build a better understanding of the issue and, more importantly, has allowed us to put in place a range of corrective actions over the last two years.

Many of these actions focus on the handling of our 120 films as the problem often arose or was exacerbated by heat, humidity and film age. These have included additional production environment controls in manufacturing and advisories for our global distribution network for shipping and storage. We have also implemented a number of important changes to make the films more robust as well as refinements to our wrapper production coating and substrates.

All of these incremental changes were successfully phased into our operations with each requiring a period of in-depth testing.

We are pleased to say that as a result we have continued to see significant improvements in the stability of our 120 films in our extreme testing conditions and no detrimental impact on their performance or characteristics. We therefore expect the number of instances of spots/mottle to further reduce as the films continue to work their way through our worldwide supply chain.

It is worth noting that with all films, but in particular roll films, issues may occur due to extremes of humidity, heat and age. We would therefore like to take this opportunity to share the best ways to care for your films:

STORAGE
All of our films, regardless of format, should be stored below 20 oC / 68 oF as shown on the bottom of each box. It is important to avoid extreme high temperatures, humidity, or fluctuating temperatures.

TIME
All films have an expiry date which is printed on the bottom of each box at the time of manufacture. We recommend processing before that date and as soon as possible after shooting. Shooting expired or 2nd hand film always carries a much greater degree of risk.

Finally, we want to reiterate our gratitude for your ongoing support and patience, and continued trust in ILFORD products as we have worked through this issue. In particular, we would like to offer our sincere thanks to anyone who has contacted us using our feedback form - please continue to do so as this enables us to replace any impacted films.

Q&A
WHY HAVE YOU WAITED UNTIL NOW TO UPDATE US?
Each incremental change we make requires a series of extensive tests which attempt to recreate or replicate the issue. As the problem is rare and not specific to a film or batch, real world testing is not feasible. As such, each change undergoes multiple accelerated aging tests as well as exposure to extreme heat / humidity to try and ‘force’ the issue to appear as well as tests to ensure that the product and its characteristics are not impacted. Each test take time to prepare, conduct and analyse.

We started our investigation shortly before the COVID-19 pandemic began here in the UK. At which point we had no idea the impact it would have on all of our lives or how we work. Unfortunately, but unsurprisingly, this has had a knock-on effect on our progress due to additional safety measures and working practices on site to protect our staff.

DOES THIS AFFECT ALL YOUR FILMS?
This issue is only relevant to 120 roll film and does not impact any of our 135 (35mm) or sheet film products.

The issue of spots / mottle on 120 film negatives is still rare and has primarily, but not exclusively, been seen in our slower speed films such as PAN F and FP4. The degree of the issue varies significantly and is also not linked to specific batches of film.

Again, while not exclusively, it also more prevalent in films close to or past their expiry date. We have also seen more cases in hotter / humid climates than colder ones.

CAN I RETURN MY UNUSED FILMS?
We will continue to replace any films confirmed as impacted by this issue. Please continue to report these via our feedback form: www.ilfordphoto.com/product-feedback

Unfortunately, we cannot take unused films back once they have left our factory as we have no control over how they have been stored or treated subsequently.

IS THE PROBLEM FIXED?
Mottle on film, while very rare, can happen due to factors such as heat, humidity and age. Therefore there is a risk it could present itself in expired or poorly stored film, regardless of manufacturer.

The last 24 months has seen a higher than usual level of complaints which is far from acceptable to us and you, our customers.

We believe the combination of the changes we have been making over this period will counteract this and greatly reduce instances of mottle, particularly with proper care and storage of the film.

That said our feedback form will remain open and our investigation will continue as we constantly look for ways to improve all aspects of how we make our products. It is worth noting that any future changes we make to how products are manufactured would again be incrementally introduced and would have no impact on the way you use them or their performance.

WHY ARE WE SEEING THIS ISSUE NOW AND NOT IN PREVIOUS YEARS?
We have been producing 120 films for many years and are one of only a few manufacturers around the world that retain the capability to do so on a large-scale volume. 120 film is traditionally a more temperamental product to manufacture than its 35mm equivalent. Fundamentally it lacks the protection offered by the cassettes. And, unlike 35mm film it needs a paper backing which can ‘transact’ with the film if not properly cared for.

With that in mind we do not believe there is a specific event or change that has caused these occurrences of mottle. Instead, several factors could have contributed to this, both during the manufacture process but also where and how film is bought, sold, stored, and used.


martedì 22 giugno 2021

Kodak HIE vecchia pellicola all'infrarosso


 You cannot make exact meter readings to determine exposure for infrared films. 

Exposure meters are not calibrated for infrared radiation, and the ratio of infrared to visible radiation varies with the light source.

Make trial or bracketing exposures over a five-stop range to determine the proper exposure for your application. 

Under average conditions, use the following speed ratings to make starting-point exposures with handheld meters or through-the-lens light meters. 

For through-the-lens camera meters, make your readings before mounting the filter over the lens. Then ignore the meter reading/readout after attaching the filter.
















giovedì 11 marzo 2021

Tempi di sviluppo della Bergger Panchro 400 e Rollei in Adox Silvermax

Dear User,
our colleagues from FOTOIMPEX have asked us to answer your question:

1. Bergger Panchro 400: Dilution 1+19, 10 Minutes.
2. Rollei  Infrared 400: Dilution 1+24, 11 Minutes.

(These times are starting points. If the contrast is a bit too high for your individual purposes, then shorten the development time a bit. If the contrast is too low, develop a bit longer.)

Important notice for the Rollei Infrared: This film is rebranded Agfa Aviphot 200 aerial film (the same is valid for Rollei Superpan 200 and Rollei Retro 400S). Aerial films have a very different ISO / speed rating than standard pictorial films for "on the ground" photography.

In aearil photography the ISO / speed rating is two stops higher. If you use that rating on the ground you will get not enough shadow detail. Therefore it is recommend - if you want sufficient shadow detail and a better tonality - to use an Exposure Index of 50/18° with Agfa Aviphot Pan 200 for normal pictorial photography. The dilution and development time given above is for that Exposure Index.

Best regards.

Team ADOX

martedì 18 agosto 2020

Test Nikkor 28mm a cura di Marco Cavina


Interessante articolo a cura di Marco Cavina che mette a confronte le diverse versioni di obbiettivi di focale 28mm prodotti da Nikkor nel corso del tempo.


giovedì 21 maggio 2020

Articolo: Uprating Hp5+ With Semi Stand Development

Interessante articolo dal sito ufficiale Ilford sul trattamento della pellicola HP5+


Questo e' il link all'articolo:
https://www.ilfordphoto.com/uprating-hp5-with-semi-stand-development/

Questo e' il link al PDF salvato dello stesso articolo:
http://www.lucaguerrifotografia.it/filespubblici/lukeelafotografiaanalogica/Uprating%20Hp5%20With%20Semi%20Stand%20Development.pdf

sabato 23 novembre 2019

Conversion from rolls of 35mm to 4x5

1 (36 exposure) roll of 35mm = 1 roll of 120 = 4 sheets of 4x5 = 1 sheet of 8x10.

giovedì 14 febbraio 2019

Kodak TMAX debeloper 1+9 diluition


Tempi presi da dev chart

giovedì 27 dicembre 2018

Giudicare sviluppo e esposizione di una pellicola

Dalla densita' dei toni scuri (chiari sul negativo) vedi l'esposizione.
Dalla densita' di quelli chiari (scuri sul negativo) vedi lo sviluppo.

(frase di Andrea Calabresi su Facebook)

sabato 15 dicembre 2018

mercoledì 7 novembre 2018

Articolo sul pre-lavaggio delle pellicole

Interessante articolo sul pre-lavaggio delle pellicole, qui sotto riporto solo le conclusioni e il link all'articolo stesso: "Conclusion: while this is not a definitive and exhaustive test it does show that there is a difference between with and without pre-soak. Those without seem to give a denser negative, which suggests that the pre-soak does have a diluting effect on the developer albeit small. This may be offset by the developer holding its temperature better because the pre-soak is building heat into the tank which helps maintain the developer temperature. This should help to improve consistency between films."

http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=202

venerdì 14 settembre 2018

Xtol and perceptol compare

https://www.photrio.com/forum/bookmarks/?type=post&id=1059704

I have tested and used both developers extensively. I have detailed tests on Perceptol at various dilutions with TMX 100, Delta 100, Acros and PanF+. Perceptol is my primary developer.

These are not the same type of developer so comparing them in terms of "better/worse" doesn't make sense. XTOL is a Phenidone/Ascorbic acid, well buffered solvent developer. It gives full film speed and actually up to about a half stop more, so it can be classified as a speed enhancing developer. At stock strength, it is both slightly sharper and finer grained than D76, with similar tonality. As you dilute it, behaviour is typical of dilute solvent developers - ie increased acutance and increased grain both due to reduced solvent effects. Indeed at 1+3 XTOL is quite sharp, and the grain increase is comparitively small due mostly to XTOL being well buffered. Also typical of dilute general purpose developers, macro contrast decreases with dilution due to controlled exhaustion in the highlights. This can be further managed with changes in agitation. It is an excellent developer, probably the best all around general purpose developer out there at this point when evaluating the balance of tonality, graininess, sharpness and speed in totality.

Perceptol is different. It is an ultra-fine grain developer based on metol and high solvent activity at a relatively low pH. In addition to sodium sulfite it uses sodium chloride for additional solvent action, making it extremely fine grained, but noticeably less sharp at stock strength than standard fine grain developers like XTOL at stock strength. Further, there is a speed loss, usually of around 1 stop compared to most general purpose developers. Dilution of Perceptol increases sharpness and grain (as is the case with any solvent developer, but the differences are smaller due to its initially high solvent action. At 1+3 (my preferred dilution), it has good sharpness, not as sharp as XTOL, but not as grainy either. In addition, being a metol only developer, dilution makes it very effective at controlling high contrast. It is pleasantly soft working.

So in summary, compared with XTOL, Perceptol will exhibit:

-Lower film speed
-Finer grain
-Lower acutance
-Lower contrast

I have two critical (in my humble opinion) recommendations for the best use of Perceptol (or Microdol), both concerning getting minimum grain, which is presumably one of the key reasons for using it. These developers are finicky about speed and contrast. If you want fine grain, you need to accept the speed loss, and the enherently lower contrast nature of the developer:

1. Determine your effective film speed at stock strength (probably around 1 stop lower than normal), and continue to use that EI when diluting 1+1 or 1+3. Usually instructions and guidelines indicate that when diluting a developer, there is an effective film speed increase due mostly to compensating action. So you'll often read that at say 1+3 for Perceptol, you can use your regular speed. I advise you not to do that. Getting anywhere near normal speed in Perceptol, regardless of dilution, amounts to an effective "push" - and it must be noted based on my tests that graininess in Perceptol is exceedingly sensitive to development time. As development times are extended, the extra fine grain properties are quickly lost.

2. Related to (1) above, same goes for contrast. Extrenely fine grain is maintained only when development is to normal (actually slightly soft normal) or reduced contrast. Do not attempt expansions. Grain will increase dramatically and you therefore gain nothing versus using a general purpose developer. I consider the lower contrast nature of Perceptol to be one if its excellent properties, but if you are interested in higher contrast work, XTOL will be just as fine grained, with significantly higher film speed.

Notes on specific films in Perceptol, developed to normal contrast, as compared to Ilford DDX (a general purpose developer):

-TMX 100 is exceedingly fine grained. Even at 1+3 the increase in grain is very small, and graininess is still noticeably finer than in DDX. I would highly recommend TMX in Percepto 1+3 for anyone looking for soft or minus development, pretty good sharpness and extremely fine grain.
-Acros is slightly grainier than TMX, but even at 1+3 still slightly less grainy than DDX
-Delta 100 is slightly graininer than Acros, and at 1+3 graininess is approximately equivalent to DDX
-Pan F+ is similar to Delta 100 in terms of the overall impression of graininess, although the grain structure is different and it looks subjectively sharper to me.

mercoledì 29 agosto 2018

Agfaphoto APX 100 developed in Kodak HC-110 two-bath

Ruediger Hartung - Agfaphoto APX 100 dev. in Kodak HC-110 two-bath
https://www.flickr.com/photos/53687643@N04/42701505105/

Two bath Kodak HC-110 compensating development
(Bruce Barnbaum- modified)

Diluted Kodak HC-110 developer, e.g. 1+119 of syrup, is strongly compensating (covers the highlights). Also shadows and lower midtones show good texture but the shadows have too little contrast.

Eduardo Almeida has already shown examples of how this can be improved using Bruce Barnbaum's method.

First a pre-development in a stronger HC-110 developer (1+43) is carried out and the remainder is developed in diluted developer (1+183). Please use at least 500 ml of the diluted developer per film!

->Dilutions based on syrup, not stock solution<- p="">
But I have changed the INVERSION rhythms a bit, following Ansel Adams.

The method works with any film according to the following procedure:

First, the development times from e.g. the app "Film Development" are obtained for the complete development of the respective dilution for the 3 (!!!) minute inversion rhythm.

If, for example, dilution 1+43 is not available but only the 1+47 time, then this time is divided by 47 and multiplied by 43. The same for 1+183, here the 1+151 time is divided by 151 and multiplied by 183.

So, now we have the respective development times (if necessary with temperature correction) with 3-minute inversion rhythm for the complete developments.

But now we only want to develop the shadows and lower mistones more pronounced (1+43) with 1/3 of the development time and the remaining 2/3 with 1+183 to cover the lights.

Therefore we only take 1/3 of the 1+43 time set above for the 1st bath and 2/3 of the 1+183 time for the 2nd bath.

Both times added give the total time.

Let's go.....

Bath A (1+43):

Bad A time, of which

half of the time is continuous inversions at the beginning, the other half stand development (important)!

Then immediately replace bath A by bath B. The clock remains running!

Bath B until the end of the total time.

Initial inversions for 30 seconds (so the remaining bath A developer is replaced), then every 3rd minute (important - not shorter!) inversions for 15 seconds.

Stop and fix.

In this case Agfaphoto APX 100 (= Kentmere 100)

giovedì 9 agosto 2018

Articolo dal sito ADOX.DE: "Keeping Properties of Developers"


We are repeatedly being contacted by analog newcomers “how long does your developer lasts” or “how long does the developer lasts after I opened the bottle”.
So we felt it is time to write a little paper about it.
Photochemisry is organic chemistry and can somehow be compared to the expiration dates on a food product.
It slowly degrades from super fresh and awesome to very well usabel, well usable, quite well usable, usable, still usable, probably still usable, possibly gone bad to “dead”.
Your joghurt does not turn bad on the day which is printed on the cap and you may possibly enjoy it even weeks later.
If we were forced to give a guarantee date, we would need to be very conservative or tolerant.
Something like:
“After purchase please use up our developers within 6 months”
or
“Our developer XY lasts in the unopened bottle between 6 months and 100 years”.
Does this help? No, it does not.
You need to find out yourself if you do not want to constantly replenish your chemistry stock.

Keeping expectations of the unopened bottle:


  • Make a judgement how long the respective product has been stored on the shelve of the dealer before it got into your hands.
If you have purchased from one of the large suppliers like Freestylephoto or Fotoimpex you can assume that every standard product has had a very short run through time. A smaller, local shop probably stored the chemistry a bit longer. In general we expect our products to arrive with the customer within 12 months after the production date at the latest.
ADOX bottles show the production date (not the keeping date) next to the barcode (exept for very small units where there is not enough space to print this information) to make this easy and transparent to our customers.
From the date of purchase we expect our products to keep at least another 12 months in the unopened, cold and dark stored original bottle.
  • Storage conditions affect the keeping time.
Ideally chemistry is stored in a cool and dry, dark place at around 8°C. This is cold enough to slow down chemical processes and warm enough to keep the usually highly saturated dilutions from crystalizing out. When crystals form needed substances are missing and deterioration is accelerated. This is why photocemistry may not be frozen. If freezing happened during transport and crystals were formed redissolve your developer as quickly as possible by gently heating and gently shaking it. Check the color. It should still be quite clear. If brown sludge (tar-like) remains do not use this developer anymore.
  • The bottle plays a key role
The gas diffusion capability of your bottles affect the keeping properties. ADOX is using very expensive and highly gas-blocking bottles since about 2015. These bottles have the shape of PE-HD bottles but they are as good as PET bottles.  Regular PE-HD bottles are inferior and no longer used by ADOX for chemistry which is subject to oxydisation. In general you can check if your bottle is made from:
  • Glas = the best option. Cat.A
  • PET or ADOX PE/PA  = very good. Cat. A
  • PE-HD or other materials which are non blocking = inferior for developers. Cat B
In a Cat. A bottle with at least 500ml of liquid the outlined keeping properties of 24 months after production should be reasonable and easily acomplishable.
  • Surface to volume equation
The larger the surface of a bottle in relation to the content inside the more important is the oxygen blocking capacity of the bottle. Small units have a by far inferior relation than large containers. On top comes that a large container has thicker walls which protect better. So to make it simple: The smaller the unit, the lower the keeping time until it spoils. 5 Liter buckets are the best in this respect. On the other hand we sell the small units so they are used up after opening. This countercompensates the keeping problems.

Keeping expectations of the bottle after opening it:


The most important question is “how much oxygen has gotten into my bottle”. The oxygen caught in the bottle reacts and uses up parts of your buffering system. When the buffer is exhausted it keeps on reacting with the developing substances and the developer starts jumping the cliff.
Influencing factors are:
  • The amount of openings of the bottle- the more, the worse.
  • Have you used protective gas or glass marbles to push oxygen containing air out of the bottle again? (plastic bottles can be squeezed within limits in the beginning to press out the air)
  • How fresh was my developer when I first opened it? The younger the better.
  • How much concentrate is left? (An almost full bottle keeps very well, a puddle on the bottom does not).

My head is spinning! How do can I tell now if my brew is still OK?


We are sorry for being so detailed but we sometimes have a hard time explaining to people why the answer cannot be a straight number.
Key indicators for a developer having gone bad are:
  • Cyrstalizations. If large crystals have formed and rattle around on the bottom it does not look good for your developer.
  • Decoloring. The fallout of crystals will be often acompanied by a noticeable darkening of the developer. Most developers are bad when they have turned darker than ice tea. However this is a relevant information only in comparison to the look of the developer when it was fresh. Rodinal in its many variants may come dark brown from the beginning on and still works perfectly even when it has the color of coffee. X-tol on the other hand should not be used when even a slight color change has occured (in relation to it´s color right after mixing). Ascorbic acid paper developers turn dark yellow to reddish but often still work. It really depends on the individual developer and this can only be one factor out of many to base a judgment on.
  • When sufficent indicators are met (age, storage conditions, crystals, decoloring) you should perform a test with a film developer to simply check if it is still usable. This is a little work but it gives you security and helps you get the most out of your developer concentrate. The only problem is: This only works if you have made the first test when your developer was still OK. Here´s how you can do this:
    • Make a mix of your developer like you would to process your next roll of film. In daylight hang in a sniplet of film (for example a piece of the tongue sticking out of a 35mm cartridge).
    • Note the time it takes to completely blacken the film.
    • Repeat this test with seasoned developer. If the time is off by more than 15% do not use the developer anymore. Below extend the developing time acordingly (5%, 10%..)
  • With paper developers it is not that critical. You see when the developer is bad. Most paper developers should develop to full Dmax in light within less than 60 seconds. If it takes longer, blacks do not come fully and/or the color shifts to brown your developer has gone bad.


Additional hints:


  • Do not buy a large amount of chemistry if you do not intend to use it. Buy only as much as you need. ADOX is offering more than 3 package sizes in most products to make it easy to buy the right amount of chemistry.
  • Consider refilling chemistry to glass bottles if it was sold in a PE-HD bottle.
  • Use protective gas, squeeze the bottle or throw glass marbles into glass bottles to completely remove all air trapped above the developer
  • Keep the cap/thread clean from dried developer. Dead developer (brown powder) works like a catalyst and speeds up the degrading of the remaining fresh developer. Avoid bottles with horizontal rings for this reason.
  • We do not recomend squeezing-bottles (the bellows shaped foldable bottles you can buy). Inside the bellows you cannot really reach to clean and old developer might reside. But most importantly the soft plastic lets oxygen pass through. These bottles are OK to keep paper developer from one day to the next but to not buy them for long term storage of concentrates. Keep the developer in the original bottle if it is a PE/PA or PET bottle. Refill developer sold in a PE-HD bottle to a glass bottle.
  • Do not use any food bottles. We did have the hospital call us up one day for a fellow who had filled Rodinal into a CoaCola bottle! Always mark chemical bottles properly!
  • Last but not least: This paper is on DEVELOPERS. Do not refill your stop bath 🙂

venerdì 22 giugno 2018

Tempi pellicola Ilford Delta 400 da 35mm

























All'interno della confezione di cartone di un rullo da 35mm di Ilford Delta 400 ho trovato indicazione dei tempi di sviluppo a 24 gradi che invece non sono riportati sul bugiardino in formato PDF distribuito da Ilford sul suo sito...