Showing posts with label bromide. Show all posts
Showing posts with label bromide. Show all posts

December 7, 2014

the new old RPX 400

 Hi coffee users and abusers,

good news about film and Caffenol. The "original" Rollei RPX 400 is back!

The RPX 400 from the very first production was a great film with good pushing behaviour and nice grain. Then the emulsion was changed obviously without any announcement. I couldn't see any difference to the Kentmere 400 now, and I never liked this film. 
 
Here is my original post on the RPX 400 with an update adressing that point:


Many people, incuding me, complained about this inaceptable behaviour. After the new package design was launched recently the emulsion obviously changed again, now showing again all the great features of the first batch. Obviously our lament was successful. Shadow detail is splendid, even with extremely contrasty subjects. EI 1600 is possible. The RPX 400 needs a powerful development to show his best side.

I used exactly the same development as before: 5 minutes presoak, Caffenol-C-L with 1.2 g/l pot. bromide, 80 minutes at 24 °C stand development with constant agitation only for the first minute. And I got the same great results as almost 4 years earlier. EI was 800, all shots done with a Dynax 5 (Maxxum 5) in multi-segment metering mode with aperture priority at f/4, no manual exposure compensation. The subject contrast was big to huge up to more than 10 stops! Only very small adjustments were made in postproduction. Shadow detail was so splendid that I had to darken them a bit.

Credits go to a friendly guy who sent me 2 films for this test. Thank you very much! And thanks to the 2 charming girls who let me take the picture.

Best - Reinhold


February 5, 2013

Kodak BW400CN

Recently I shot my first roll of Kodak BW400CN, a chromogenic b/w film. A first experiance in C41 color developer slightly pushed turned out very good at EI 1600, and I wanted to try Caffenol. I'm not a big fan of color film developed in b/w developer, but this BW400CN developed in Caffenol-C-L is as good as developed in color developer. No doubt. This film is ideal for high speed purposes and hybrid workflow. You can push this film a lot and still don't get to much contrast, for the sample image attached here I even had to enhance the contrast in pp. Grain is still very small, almost unvisible with my Canoscan 8800F. The look is very different from other films, probably ideal for taming highest contrasts. The orange mask is very transparent and the base fog very low.

So here's a sample, no masterpiece for sure, but showing the character of the film under very low light conditions at EI 1600, simple average metering with my trusty Canon A1. Developed in Caffenol-C-L semi stand with 0.5 g/l pot bromide, 20 °C, 70 minutes, fixed in regular bw fixer, increased contrast (s-curve) in Gimp.



Best - Reinhold

July 11, 2011

the salt in the soup

Hi coffeeholics,

good news, using regular, non-iodized salt works as a restrainer and can replace iodized salt or potassium bromide.

For the test I made a demanding setup, Rollei RPX 400 @ 800 stand developed @ 24 °C in Caffenol-C-L urgently needs a restrainer, without you will have huge problems concerning massive fog and uneven, cloudy, streaky development. Last afternoon I shot the 35mm film and cut it into 3 peaces. One was developed with 20 g/l regular non-iodized table salt aka sodium cloride. For the second piece 12 g/l iodized salt (0.0025 % iodate) was added and the third piece got the addition of the well working 1.2 g/l potassium bromide aka KBr.

Regular table salt without iodine (20 g/l) works good enough to prevent any streaks or uneven clouds in the image, that you will get with stand development if no restrainer is used. Yellowish stain and quite a lot base fog can be noticed. Again, base fog is not as evil as often told as long as the develoment is even. I guess that 30 or even 40 g/l will be fine for fast films.

Iodized salt (12 g/l), although much less is used, works slightly better with a bit less base fog, but still even enough developed that the image is not disturbed, only some unevennes at the borders where the spiral covered the film during development. And the stain is also less. Iodine does a good job. I would now adjust the salt to 15- 20 g/l for fast films, slow films need less salt.

You can see that KBr (1.2 g/l) gives the least fog and no stain, perfectly even developed, no surprise at all.

I couldn't notice any significant differences in grain or effective film speed. EI 800 was fine.

Here's an example with the regular table salt, no post processing exept a bit unsharp maskening and scaling. The neg was really quite dark due to the high base fog level. Do you notice any drawbacks? I can't. And increasing the amount of salt will probably reduce the fog. But most important, the development is even, no streaks, no clouds, simply fine.

It was a rainy day, so an orange filter was used. Probably I overdeveloped a little bit. It was really war in my lab and temp increased up to 25 or 26 °C during development. There's a break point in time and temp, if you exceed it, the RPX 400 shows immediately increased fog and grain. So that was probably a little bit too much. But all three chunks were developed simultanously under the same conditions.

These are my very first experiances. Go and try regular table salt and let me know how it works for you. It will work with other Caffenol variants to. Sharing your experiances via The new Caffenol Home on flickr is much appreciated.

Cheers - Reinhold

important update: my flickr buddy Rob showed that salt (sodium cloride) causes dichroic fog. Since iodized salt is widely available it's recommended to use it because you need much less salt and dichroic fog is less. Adjusting the amounts for your needs is quite easy. Potassium bromide still is the best restrainer but I love the idea of using commonly available agents.

June 28, 2011

reuse or not?


Hi,

sometimes I reused a caffenol batch. Up to 2 weeks of storage I could not find any major drawbacks, maybe a slight loss of contrast. Here I reused an only 2 days old one, one 24 exp. 35mm film was developed with it. The negs were underdeveloped remarkable, the border printing was faint and overall density quite low. So I had to brighten up the images and work on the curves quite a lot. Fortunately there was still enough substance to do that. It whould have been a shame if this picture would have been ruined. So I stay on the safe side in the future and will discard the developer after a single use like I did in the beginning. But there's no need to hurry, the developer will remain usable at least some hours without degradation.

Rollei RPX400 @ 800, Caffenol-C-L with 1.5 g/l pot. bomide. 90 minutes 22 - 23 °C stand development. Presoak 5 minutes, constant agitation in the first minute, 3 gentle inversions at 2, 10 and 40 minutes.

Cheers - Reinhold

November 29, 2010

HP5+ @ 1600 and Tmax3200

 


Hello everybody, Reinhold invited me to write something about my latest Caffenol results.

After using the Shanghai GP3 100 at 400 ASA in Caffenol-C-L and Reinhold´s pleasing results with T-MAX 400 @ 1600 ASA I was curious to use some films in the 400 ASA+ class.

The first picture (engine of an shot down WW2 plane) was taken with my Seagull 4A TLR on Ilford HP5+ film. In fact it is labeled as Adox CHM400. I gave it a try at 1600 ASA developing it 70 min at 20° in Caffenol-C-L using 1 - 1.3 gram per liter potassium bromide. I call it a "semi stand" development, agitating every 10 - 15 minutes. I was very pleased with the result and the amazing fine grain. Second picture (a set of gauges in an old submarine) was shot on 35mm HP5+. Bevor insolvency Ilford sold lage amounts of master rolls to other companies, so this film is labeled as OrwoPan 400. The film is rather old, being expired in 1996. Like the MF version it was exposed at I.E.1600. I was really amazed about the nice grain at this speed and format. In other developers, I´ve got more grain at box speed.

OK, Caffenol-C-L is very useful using expired high speed films, I thought. Let´s try something special. By chance, I´ve got some rolls of long expired (1997) Kodak T-MAX 3200 years ago. Never got any usable reults with this films, too old. So I grabbed one of the films, threw it into my Pentax Spotmatic and exposed it at I.E.1600. Surprise, the whole film was usable! Here is one of the results. As you can see, the grain is very pronounced.

Both 35mm shots were developed 70 minutes as described above. Click on the pictures for a bigger size.

Happy experimenting!

Wolf

October 28, 2010

More Tmax400 - Caffenol-C-L


My Caffenol variants deliver reproducible results and I use them for even the most delicate jobs. Here again 2 samples with the Tmax400 in Caffenol-C-L with 1g/l KBr, semi-stand development, 60 minutes at 20 °C. 5 minutes presoak, 10 inversions initially, 3 inversions at 1, 2, 4, 8, 16 and 32 minutes. Left image exposed at EI 1600-3200, right one at EI 800. Don't use at EI 400 or less, will be overexposed with blown highlights, or reduce dev time! 800 - 1600 will produce best overall quality. If not pushing too heavy, the tonal range is comparable to Acros100 at EI 200! Both are ideal for scanning and highest subject contrast range.

Caffenol-C-L has proven to work greatly with high speed films. So it's usable for almost any kind of film.

Best - Reinhold

August 16, 2010

Caffenol-C-L stand development

Real stand development with TMax100 as 120 type film. Shot with my 65 years old Bessa 66, vignetting of the first picture caused by filter (old fashioned yellow-green) and lens shade. Coloured with Gimp. First image EI 400, second EI 100, same roll. Click on the images as usual for bigger size.


Recipe as posted before, but only 1 g/l bromide. 5 minutes presoak in tap water, 10 gentle turns at the beginning, then let stand without further agitation. 60 minutes at 22 °C. Stop, fix and rinse as usual.

BTW, C-C-L has a pH of about 9.0

Perfect transparent film base, no fog, very little yellowish stain from the coffee. Usable on the same roll from EI  50 to EI 800.Scans very easy and surely will print at EI 200 - 400. For wetprints from EI 100 and below you should reduce dev time, otherwise negs become very dense, but no blown highlights!

My best Caffenol so far.

I love coffee - Reinhold

August 12, 2010

Caffenol-C-L + high speed film


Recipe and semi-stand development as in former post. 50 minutes at 22 °C. Remember to adjust dev times as usual for differing temperatures.

Neopan 1600 exposed at about EI 1600, difficult to tell with night photography. I'm confident to gain real 3200 with longer development.

Shot with a 35mm SLR and very cheap telezoom lens. Crop 10x10 mm negative size

Caffenol-C-L is a breakthrough with high speed film imho. Very low fog level, sharp, nice and small grain for 1600, very wide tonal range, perfect even development.

I love coffee - Reinhold

August 4, 2010

perfect development with Caffenol-C-L

2 posts belowyou can see the effects of different agitation. From extreme uneven development with stand development to a dramatic improvement with standard agitation. 

When adding the restrainer potassium bromide (KBr), we see perfect even develpment up to the reel covered borders - even with minimal agitation as shown here. With intension I made no proper black adjustment here to show the improvement in the clearest possible way. 

So here's my recommendation:

If you are satisfied with "regular" Caffenol-C like C-C-M, be happy. If you experiance uneven development, agitate more (you will have to adjust developing time). If still not satisfied use Caffenol-C-L. 

The benefit of C-C-L besides the 100% perfect even development are reduced grain and almost fog free negatives.

Caffenol-C-L will be my standard in the future.  My 100 g box of potassium bromide will last for a couple of films ;-) Caffenol-C-M will still be my standard as an easy to use and easy to get developer with enhanced film speed..

 So if you can get KBr for a resonable price in your country, buy it! You won't be disappointed.

Cheers - Reinhold

August 1, 2010

Caffenol-C-L


First results, Minolta X-300, 50mm Rokkor, orange filter, APX 100 in Caffenol-C-L

Recipe:
16 g/l washing soda waterfree, 10 g/l Vitamin-C, 40 g/l instant coffee, 1,5 g/l potassium bromide (KBr)

Use 1 - 2 gram/liter KBr, 1,5 seems to be a good idea. Do not use more than 2 g/l, it will restrain development too much up to blank negs.

40 minutes semi-stand development at 24 °C. Agitation first minute continuos, 3 inversions each at 2, 4 and 8 minutes, then let stand.

No fog, fine grain, perfect even development, about boxspeed.

Maybe some minor tweaks in the future, but looks fine so far. 

Maybe not everybody is able to get potassium bromide easily? I got it from my next door pharmacy. It's not toxic and environmentally safe with the used quantities.

Looks promising that C-C-L may also be good for high speed films.


Do not try (semi-)stand development without a restrainer like KBr -> agitation is the key! 

PS: I didn't use semi-stand development for another reason than comfort, I don't like shaking for half an hour. ;-)

Cheers - Reinhold

uneven development

 click on the picture for bigger size

 Some people report uneven development and/or disturbing fog. That effect appears almost always with classic (cubic crystals) emusions like Ilford PanF+ or Agfa APX 100. Not enough agitation is the cause. A drastic example is stand development with Caffenol-C, as you can see in the image above.

What is happening? Lets regard the left picture. Stand development makes it visible. Classic bw-emulsions contain a lot of silver-bromide, the silver is reduced by the developer to form the blacks, and the bromide is set free. Bromide is a strong restrainer, but without or too less agitation it sinks down in the tank and produces less development, marked with a red "x" in the left picture.Also below parts of high exposure more bromide is set free and causes streaks. Below the sprocket holes, less bromide is set free leading to stronger development. Finally the bromide accumulates at the bottom and there we find the least development and - the least fog!

In the right picture with regular agitation we see no eneven development or fog at all exept for the small upper and lower parts covered by the reel during development. The bromide is dispersed evenly and so we have a constant restraing effect over the whole area. The uncovered upper and lower borders are developed evenly  with low fog level, see the red "x"-es.

So agitation is the key for even development. Of course there is some remaining general fog,  but doesn't disturb because it is spread evenly over the whole film. If you get uneven development or disturbing fog, agitate more! Try the heavy agitation regime recommended f.e. for Xtol, 5 times in 5 seconds every 30 seconds. That's almost shaking! And reduce dev time when doing this! Time, temperature and agitation are closely related, keep that in mind always.

My trial with stand development was very revealing. It was done when experimenting with low-pH Caffenol-C. As the development times with low-pH will increase and I didn't want to shake the tank for 20 or 30 minutes, I gave stand development a try. With the shown faults. But - when adding the bromide in a good amount from the beginning as a separate agent, unevenness and fog will be gone! So stay tuned and await a new Caffenol-developer by me, it will be named Caffenol-C-L. Only a little bit of fine tuning necessary.  Compared to C-C-M it will have a bit film speed loss, but probably still boxspeed, finer grain and fog free even with stand development!

With "modern" medium speed films like Acros100 or Tmax100 things are different. They contain much less bromide and are much less fog sensitive and show perfect even development with C-C-M. Maybe C-C-L will also be recommended for high-speed films. So some things to do in the future, it doesn't get boring at all.

Time for a cup of coffee - cheers - Reinhold

July 23, 2010

3200

Fuji Neopan 1600 @ 3200, Caffenol-C-H. First trials @ 1600 showed that there is still some headroom for underexposure. Yep.

May 11, 2010

Caffenol-C-H "highspeed"


Hello coffee junkies,

a new chapter of Caffenol development is ready to be published. I was not satisfied with Caffenol/C and high speed films and I didn't recommend it. Too much fog, flat in contrast, poor usable speed, ugly grain. but I constantly thought of trying to modify Caffenol-C-M for these films. Potassium bromide (KBr) is well known as an anti-fogging agent, but I thought it would mess up the concept of great shadow rendering. I was wrong. So good and bad news: KBr works well with Caffenol, but it is not available in regular supermarkets. In Germany a pharmacy in my neighborhood was able to deliver it within a couple of hours, 100 gramms for 15 Eur. Quite expensive compared to the other ingredients, but it will be good for 100 litres of developer and some hundred films. So the additional coast will be about 4 - 8 Euro-Cent per development. Potassium bromide is not toxic and doesn't spoil the environmental friendly coffee soup.I don't know how easy potassium bromide is available in other countries, reports are welcome. The german name is Kaliumbromid, or you may ask for the scientific latin name "kalium bromatum" in pharmacies.

Crops 10x10 mm negative size, Neopan 1600 @1600 ASA left, HP5+ @ 400-800 ASA right :

So here's Caffenol-C-H, "H" for highspeed, recommended for 400 ASA films and faster. There is considerably less fog, although there will be still some, but not any more disturbing. Tonality, contrast and shadow rendering are amazing for available light with lot of shadow areas. On the minus side we have still quite big grain. For example, the Neopan1600 developed in Diafine produces much nicer grain and was my preferred developer. But I never got better shadow details as with Caffenol-C-H. And I slowly begin to love the bigger grain, together with the wide tonality it gives a special look. Boxspeed or pushing is possible. More detail for exposure index must be evaluated, rating under available light conditions is difficult and I made no densitometric tests. Try boxspeed or +1 push.

How to: I made a stock solution of 10 gramms KBr in 300 ml destilled water, stored in a glass bottle. It will last almost forever. 1 ml contains 0,033 gramms KBr. 250 ml developer need 7.6 or easier 8 ml of the stock solution. This equals 1 gramm per litre KBr. Simply add the 8 ml to the ready mixed 250 ml Caffenol-C-M and voila: Caffenol-C-H. Be sure to do the math right! I'm sorry.

Edit: if still too much fog, use 2 g/l of potassium bromide.

So far I used HP5+ and Neopan1600, both with excellent results. 1gram per liter KBr was added to the Caffenol-C-M recipe, no other changes. Developing time was 15 minutes like before, or 30 minutes stand development with agitation first 30 seconds and 3 minutes presoak in tap water.

Thank you very much Caro and Chris for allowing me to publish the images. Finally an example of the Acros100 in Caffenol-C-H, also works perfectly. But for 100 ASA films I still recommend the simple Caffenol-C-M because the KBr isn't really needed.

Best regards - Reinhold


Acros 100 in Caffenol-C-H, 15x15 mm negative size, the bromide doesn't disturb