Film Matter: Clearing Out Old Film Stock and the Right Soup

Dear Readers,

You probably expected another part of the sequel Building a small exposure meter, right? Unfortunately, I had a major headache with the purchased digital panel voltmeter as the display for the meter. It looks like a shitty electronic component, with a weird output, so I need first to find out where the problem is, or another voltmeter....But at least, the circuit (with some minor modifications) performs well, with an even lower error as I calculated. So expect to see the final part of the build next week (or a week after). 

The "breadboard" version of the exposure meter works well, but I am still in search of a usable panel meter.

And these are my very last outdated films from the "old good days".

While shuffling my photo stuff, I came across a bunch of films I put out of the freezer a few months ago with the intention to shoot these films at last...trouble is, all 4 films are more or less of the »specialty« type-very high or very low sensitivity, and one is for tungsten light as well. But all of them were venerable emulsions back in the day. So I'll need to pay some respect to them when shooting. The EPT 160T (slide film) will be most likely used when I find some nice happening, like a concert, same for the Tmax P3200. As for the APX25 and the »holy« TechnicalPan, I am not really sure when, but they'll be used probably for some landscape stuff. Ok, this is my business what I should do with these films, but when it comes to develop these BW films, we all have the same problem - in which soup we shall develop the old outdated stuff. For the TechPan and the APX25, I'll probably just use Rodinal or its »clone«, the R09 developer (quite similar, but closer to the original pre-WWII formula), except that for the TechPan I shall use a highly diluted solution. Rodinal is quite a flexible chemical, since you can mix it with a buffer (the plain formula is highly alkaline, but it's not buffered), most often with borax, giving a more gentle development. If you haven't tried Rodinal (or R09) yet, give it a go, especially for low- or medium-sensitivity films. Here you can also find the link to the legendary Unblinkingeye article (written by Ed Buffaloe) on Rodinal and its flexibility.

As for the P3200 (very prone to fog), I am not quite sure how to »soup« it, but most likely I will mix up the post-WWII developer formula, reportedly invented by the Czechoslovak ing.Koblic (a great photographic inventor BTW). After the war, there wasn't any fresh film stock available in Europe (and we had other greater problems then), but only old, mostly highly outdated film stock. So ing.Koblic came out with the formula to preserve film's sharpness and keeping down film fog (to be expected otherwise with old film).  Here is the formula: 

Metol - 4 g
Sodium sulfite (anh.) - 16 g
Disodium phosphate (.12H2O) - 4 g
Borax (sodium tetraborate) - 8 g
water to make - 1000 ml (pH around 8.5)

Here disodium phosphate acts as an antifog agent, in contrast to other developers where potasium bromide is usually used. As for the developing time, one should find him/herself the most appropriate time, but reportedly up to 15 min should do the job, and the developing time shouldn't be so critical (in case of a too long devlopment). Here is also a link to APUG where this developer has been discussed a bit, but not too much unfortunately.

My bottom line above all this is: I am always fascinated how many developer formulas have been invented over the decades, some simple and some (many) very complex. In the end, we often come back to the simplest ones, since they work so well (and Rodinal is just one example). It never stops to fascinate me how can such a (relatively) simple black-and-white chemistry produce such outstanding results, over and over again.

Mitja

Random Quote

"My job as a portrait photographer is to seduce, amuse and entertain"  Helmut Newton

Portfolio of the Week: Niccolò Barone

Dear Readers,

This week we feature another Italian photographer, Niccolò Barone. He is an autodidact photographer. He works essentially in medium format (Hasselblad 503/500, Rolleiflex 2.8f, Pentax 67, Minolta Autocord, Mamiya 645 and some others) and 35mm (Leica M2, M4, M5, M6, Contax II, Nikon fm and some others) as well as with polaroid and Holga cameras, with available natural light as his favorite lighting source. His preferred films are Kodak Tmax 400, 100 and 3200. He develops BW films by himself, usually with Xtol (Kodak) or Gradual (Ornano) when he shoots at low film speeds, and HC110 or R09 when exposing film at high ISO. Yes, noise and graininess is a matter of choice for him.

Niccolò’s photography really focuses on many diffrent things, but essentially on the female form, most images are solitary and the most part is in black and white. When you look upon the photographs you get the feeling as the portrayed women have all endured some kind of hurt, not the physical kind though. All seem lost in their thoughts, gazing out toward distant lands, even those gazing right through the camera lens, are not really seeing, expressions are vacant and glazed.
Most of his inspiration comes from the classics, and some from the web where there's a great number of talented photographers and beautiful photographs. He has already been featured in a number of publications, including Vanity Fair. His work is certainly one of the most accomplished you can find on the web. Niccolò’s work can be found on Flickr on his first and second photostream and on his website. Enjoy his photos!

 All photos copyright: Niccolò Barone

Monday Column: The Right Tool for a Hill Walking Hike

This Friday my brother, I and our uncle will go hiking in the beautiful Slovenian Julian Alps. More accurate: We want to get to the highest mountain in Slovenia. This is Mt.  Triglav, 2,864 metres (9,396 ft) high. It’s a two day hike, first day up, sleeping in the Kredarica hut and the next day down. It’s a 2200 meters (7,218.2 ft) rise and then descent.

First mountain hut "Triglav temple" at opening 1871

source:http://www.gore-ljudje.net/novosti/52045/

Now, I’m a photographer. So I want to take a photographic camera with me on the hike. But it’s will not be an photographic excursion, As a contributor to this blog, would be inappropriate to take with me a digital camera (I admit I will be using a small P&S for snapshots... I’m guilty). So my dilemma is which camera to take with me to the hike? Why dilemma? Take your best camera you own or camera that you could give you the best performance, or the camera you prefer the most and enjoy shooting with? Hm... Probably the best camera, none the less of its simplicity, is my Russian large format camera FKD 18x24 cm or 7x9.5 in, with its wooden tripod. It would require a Sherpa to take it to the mountain top, but they are scarce in those mountains (satire alert!). Probably the second best quality would give me (loan from my friend) Kowa 66. This is a medium format 6x6 cm camera. Here is no need for help from Himalayas but it is large and heavy and bulky. Remember the rise? Much lighter and also with enough quality would be my Canon EOS 100 and some lenses. Lightweight would be with 24 2.8 and 50 1.8 lenses. But is also too much bulk, and I already explained in the last column what’s for me analogue shooting. I have only a small backpack and must take with me all necessary for two day trip and this season in mountains has already fell first snow... 

  Secovlje Saltpans shot with Agfa Isola 1

The most lightweight option would be my Agfa Isola 1 and Altix-n. First is a medium format P&S from late fifties and early sixties. It weight’s only 300 g. Problem is that the number of exposures is limited to only 12. And it has only one shutter speed (1/30 s) and only two aperture values: cloudy f11 and sunny f16, and quality of the lens is in the lomographic territory (I like it). The other option is a 35 mm fully manual “guess the distance rangefinder” with nice 50 mm f2.9 lens. But it lacks the mf look and it’s heavier.  

 Secovlje Saltpans shot with Altix-n

I must decide by myself but I want to hear your opinion. What do you think about my options and what would you bring to that kind of hiking from your arsenal?

Cottage Tip: Building a small exposure meter-Part II

I got (almost) all I need to build the actual meter (save the voltmeter, it should take quite longer to come, not really sure why). I got the LDR sensor, so the first thing I did was to build some kind of enclosure and light diffusor around it. I just recycled a piece of black plastics for the base and the middle of the (Fuji) film canister cap for the diffusor. I drilled two holes in the base for the sensor leads and painted the inside of the cap with white opaque nail polish (taking care to make an even layer). When the nail polish dried, I glued the sensor on the base and then glued the white-painted cap onto. I know, it is not exactly a dome-shaped diffusor like in commercial meters, but probably (hopefully) will do the job more or less in the same way. It is more like a »hybrid incident light adapter« between the dome-shaped and the flat diffusor (the ones used to asses the contrast ratio). See photos below.

Starting materials for the sensor: light-dependent resistor (LDR), black plastics for the base, white nail polish and a Fuji film canister cap.

LDR glued to the base, and the cut mid-section of canister cap painted inside.

The sensor assembled on the breadbord (don't mind the resistors nearby, they remained from a previous project).

The so-prepared sensor was ready for testing! Unfortunately I came home quite late, so I catched the last sun rays. There wasn't a 15 EV intensity anymore, but only about 13.5 EV.  Then, I measured the response-resistance down to about 4 EV at different values.  I then plotted the dependence of LDR resistance against light intensity (EV). The outcome was quite a nice exponential curve (as it should be) with a very good correlationship.

The testing rig: multimeter measuring sensor's resistance and the Minolta exposure meter for getting the actual EV value.

I then used the obtained formula of the curve equation to calculated the predicted resistance at a given EV value (also for the points I did not measure). Then, the calculated resistance values served to calculate an appropriate series of voltage values to be obtained between Rx and R1 (voltage drop across R1; see the previous post). For that purpose I used the first part of the formula:

U_OUT1= (U_Z2 * R1)/(Rx+R1)  

Where U_Z2 is the voltage of the Zener diode (supplying the voltage to Rx and R1), Rx is the value of the LDR and R1 is the chosen resistor value.

Now, I must confess, I wasn't really picky about the Uz and R1 values, but I tried to match them to what I have at hand (and/or combining various values), but anyway, I wanted to get satisfactory results, at least. So for Uz I chose a Zener diode with voltage drop of 3 V and for R1 I chose the value of 3200 ohms (3k+2x100 ohm).

I got this, quite a linear curve:

The curve equation now tells me that if I want to get the output of about 10 mV/EV I first need to add (offset) 1290 mV to this (voltage) signal and then divide it by a factor of about 28.4. Very luckily to me,  1290 mV is quite exactly the voltage drop of 2 regular diodes connected in series(cca 1.3V)! This is not necessarily the case, but luckily for me, it was. Otherwise, I would need to use another Zener diode and a trimmer to adjust the offset voltage, in a slightly different circuit arrangement. Using a different LDR  and light diffuser would certainly yield different values and curves. For the voltage divider I didn't use exactly the factor of 28.4, since the calculation  gave too much shift from the theoretical values, especially at high EVs (where the meter is used mostly). Given my resistor choices, I opted to use 1267 ohms for R2 (1k+220+47 ohm) and 47 ohms for R3. This gives a ratio of 1:29.57. By applying this ratio and the voltage bias of 1300 mV (two diodes), it gave me the following (calculated) measurement error at different values:

At first, it doesn't look like nice. But, we seldom use a meter below 6 EV (very dim light), and the error of around 0.3 EV is totally acceptable in practice for cameras and meters alike. Only between 11 EV and 13 EV the error is quite large, but as long as we know how much the error is, we can always correct for it. But clearly, all this is still theory only. The practical measurements will tell how good or bad the meter is.

Anyway, at least I came up with the final version of the circuit, with resistor and diode values to test, and hopefully, solder into the circuit board. See below (this is only the signal part of the circuit). But let me stress once again: this circuit is (should be) suitable for MY very own case of sensor, not necessarily (or likely) yours!

The signal part of the circuit I came up with.

The diodes D1 and D2 are just ordinary small-signal diodes. The Zener diode, as said, has  a drop of 3 volts, while the resistor Rz has been set arbitrarily at 4.7k, just to get a current somewhat higher than 1 mA, (at high EV values current can approach about 1 mA in this configuration). Voltage drop across Rz is 7.7 V (12-3-1.3), divided by 4700 yields about 1.6 mA. The photo below shows a more general (and probably also more appropriate) case of a signal circuit-using another Zener diode and a trimmer potentiometer to adjust the bias voltage. The latter is probably the largest source of measurement error in such a meter:

A more generic signal circuit.

During the weekend I'll test the sensor and circuit on the protoboard (»breadboard«), and I am quite anxious to get the results, which I'll promptly report to you. If time will permit, I'll also get in the final construction till next time.

Silver regards

Mitja

CORRIGENDUM: While the circuit in the penultimate photo (without the trimmer pot.) is in principle OK, your restless editor forgot for a moment a basic aspect of Ohm's law, and a vital coefficient....Therefore, the correct values for R2 and R3 are 1.267 M ohm and 47 k ohm, respectively. I apologize for that.

Plustek OpticFilm 120 update (and a rant)

It was one of the first posts on the blog  about this medium format scanner. The actual market release date still seems to "float". When should this happen? Who knows, I don't. The vendors have been accepting preorders for the scanner for quite a while now. The feaures look promising, at least on paper. Not so for the price. Wex Photographic offers the scanner (in pre-order, of course) for £1999. Wow, that's serious money, 2.5k€! In these days people get a medium format camera in mint condition for some 15-30% of that amount! And you can get a (used but working, of course) Imacon or drum scanner for that sum.....I really do not understand who will ever buy such a monster (price-wise). If one needs to scan MF film for sharing online, then a Canon or Epson flatbed does the job just right, for 10% of that price. When you ever need high quality scans (exhibitions, print sales), then it's just better to pay a professional to do that. But yes, it is a problem to find a good professional these days.....I don't know for you, but I'm not gonna buy it. Not in a million years. If I ever get crazy one day, I'll get to scavenge an old drum scanner....and a SCSI adapter :)

Portfolio of the Week: 4Spo

Dear Readers,

We have moved back to Germany and feature another great photographer from this great country, 4Spo. Of course, 4Spo is not his real name, as he wanted to preserve his privacy, but that's his username on Flickr. And that's OK, we respect your privacy-it's your work that counts. He is with no doubt a modest guy, even though his work tells another story, and he mainly defines himself as a fan of Peter Lindbergh.  No doubt he is a die-hard guy as well! After a few years, he happily came back to film, using the many fine cameras in his possession: Leica, Plaubel, Hasselblad, Nikon etc. He has no particular preferences for film brand or type, but he likes very much expired film for its unpredictability and the effects it gives. Possibly with the lens wide open-another bokeh fetishist, I would say. He states that he likes the subtle eroticism in photography, with a nice bokeh, with the great help of film medium. And he obviously makes his job right! Also in the fashion/editorial field.  Enjoy his work! 4Spo's work can be found of Flickr on his website, along with his colleague work.

Mitja

All photos copyright: 4Spo