Finding the edges of Eukobrom AC will hurt your pocket.

One open ,One untouched.

I have some good and bad news concerning Tetenal's Eukobrom AC. I have been pushing the developer to find it's limits. Without knowing where the edges are you cannot be sure that you are getting the optimum usage.

The good news is that two litres of diluted developer at 1 to 9 stored in a slot processor will remain usable for up to six weeks. Obviously this will vary depending on your circumstances. Also as the developer gets older the solution becomes more brown. Along with this it imparts some of this colour to the photograph by producing a subtle chocolate brown warmth in this case with Kentmere select RC gloss. A paper I have been using alot.

Used and depleted

The bad news is, while I have been involved in seeing how long a working solution will last, I forgot to mark the stock bottle with an 'opened on date'!. As a result 800 mls of unused developer has been thrown away. The first time I have had to do this ever! 

    

 I discovered this 'error' at the start of a printing   session. The existing developer was tested for   usability and found to be no longer viable. So I   made up a new batch to find that this was also   depleted. I was suspicious that the open bottle   was off by the colour but made up a new batch   anyway. In the past with other traditional   developers the colour does not always indicate   that it is exhausted. It took time to find out for   sure as the new developer was producing a very   soft test image without any contrast. I was using Kentmere paper, not known for being on the soft side and very quick to produce an image when placed in the developer, seconds in fact. In this case it still was not right after two minutes. After several attempts it was dumped. Not impressed to say the least.

Continence from open
bottle

Test Prints from open bottle of Eukobrom AC 

Not to worry I had a new unopened bottle. However on pouring the new bottle into the measuring jug this was brown in colour as well. Not the slight orange colour I was expecting. Now I was angry. I made up a batch anyway and to my surprise I was met with a well developed test image. Fully toned, great!

It took over an hour to get to this point what with one thing and another. My temper mellowed as each successive photograph left the developer fully toned.

Developer from fresh
bottle

Developer from
fresh bottle.

Test print in fresh developer..

Will I use the developer again? I still have the best part of a litre left from a dodgy opened bottle that has an 'opened on date'. As long as the contents are viable I will use it again. As to re stocking it? Not sure? It is just as well I keep some of my old friends in stock.

I did email Tetenal a long time ago to find out if they had any suggestions as to why this should be the case but have had no answer, I can share with you at the point of writing there is still no answer on posting.  

Printed on Kentmere RC gloss paper developed in Tetenal Eukobrom AC

This post was first published in 2017 there has not been any response from Tetenal on my concerns to this date.

Living with Tetenal Eukobrom AC

Developer

Tetenal new Eukobrom AC is proving to be a delight to work with. I did not realize how much of a irritant the smell of the developer was until it had been removed from the equation. I no longer have developers nose where the smell lingers long after I have left the darkroom. 

In an early article on this developer I had a couple of questions: Personally the main questions yet to be resolved are its keeping qualities and whether or not the image will be warm when the developer starts to deplete. One of these has now been answered, that is it's keeping qualities. I have been using it in my slot processor, at the end of each print session I leave the developer in the slot and cover it with the lid. The amount of time between each print session varies a lot from days to weeks sometimes months.

Slot processor

 Two things have come to light. If you leave the developer in the slot you should give it a stir before you start using it again. The active ingredient can separate out dropping to the bottom. I was caught out thinking that the developer had come to the end of it's working life because it had been left for two weeks. Something I did regularly with Ilfords multigrade without loss of usability.

Something else I have not experienced before was a black and white crystalline substance on top of the stop bath. It was a very heavy build up making it difficult to remove the top off the stop. The stop it's self was clear and still at the level it had been left at, turning out to still be working even so I changed it. This maybe an interaction with the vitamin C - something to keep an eye on.

The other question about the warming of the prints as the developer depletes still remains unanswered. This due to the fact I have not processed enough prints with the fresh developer. Once I notice I'll let you know.

 

Finally I have used this developer with a number of makes of paper now - RC and FB, natural, warm, cool tone and tinted papers - With great results, so if you have not tried it yet, do so! you can get it in 250 ml shots which is More than enough to get a feel for the way it works and looks.

Technical Data:

Developer Tetenal Eukobrom AC, paper Kentmere RC gloss. 

Other Posts:
Eukobrom first look
FB papers in Eukobrom

FB papers developed in Tetenal new Eukobrom AC.

Four papers side by side.

There is not a great deal I can add to what I have already written about Eukobrom AC. I was not expecting to show you a set of FB prints so soon after my first use of this new developer. The questions I still have need a good amount of time to pass.

A partial answer to one question is that the developer will keep for at least three days after dilution. As long as it is bottled at the end of each session when being used in a tray. A litre of 1+9 strength so far has produced twenty images of mixed sizes. According to Tetenal you should get about 1,353 prints of 30 x 24 cm out of each 250 ml of concentrated developer. Which works out at about 54 prints per 100 ml diluted at 1+9. Obviously in practice this will vary depending on dilution, paper and conditions of use.

While I was developing the FB images I did notice that different    papers could take up to sixty seconds before they started to show any signs that the paper had been exposed and a further sixty to complete the process. Knowing when the increase in images appearance is down to reduced developer activity will take time to discover.

Ilford cooltone fibre base paper

I chose three makes of FB paper: Ilford cooltone, warmtone and natural - all gloss, Fomatone MG classic chamois 542 mat and Adox MCC gloss. All the papers were exposed at grade three but unlike their RC brothers the exposure time had to be adjusted as some of the papers required a lot less light. Again the tones had good separation, rich blacks and clear whites.

Of the three Ilford papers the natural paper took on a cool tone, where as the cooltone took on a warmish tone. This could be the first indication that the developer is depleting. If this is the case then it is exhibiting the same traits as those traditionally produced. The slight colour change indicating that the silver has not been fully developed. I have written about the changes of colour you can expect from exhausting developer in another article.

 

Fomaspeed 524 matt warmtone.

When it come to pushing or pulling the print (This is where you over expose the paper then pull it from the developer when it has reached full development before the suggested time for full development.) I have so far kept to standard use.

Adox MCC fibre paper

If you have not tried it yet give it a try. If you have used it let us know - always interested in what others think.  

         Link to previous post on this developer.

Tetenal Eukobrom AC first look

I like trying new things out in the darkroom, so when an offer to use Tetenal's new monochrome paper developer Eukobrom AC came up I jumped at it. I would like to thank Matt of AG Photographic and Tetenal for the chance to be one of the first to give it a test drive. A few weeks later a package arrived at the door, since then I have been chafing at the bit to try it out.

This is a new developer made for twenty first century. It is also the first commercially to use isoascorbate, vitamin C (you're not seeing things) as the main developing agent, it is a direct replacement for Hydroquinone the most widely used ingredient in photographic developers, noted for it's fast action and high contrast. It is marketed as the alternative to Ilfords multigrade all purpose paper developer producing the same sort of neutral tones. The developer works with both Fiber Baryta and resin coated light sensitive papers, whether multigrade or graded.

Top row: Ilford multigrade RC paper. left side in
multigrade developer. Right side Tetenal.
Bottom row: Fomaspeed variant RC paper. 

The data at the moment is quite sparse.

Technical Data:

Fibre Baryta Paper (FB)	Dilution	20C	25C	30C
	1+4	90s	70s	50s
	1+9	100s	80s	60s
Resin coated paper	1+4	50s	30s	15s
	1+9	70s	50s	30s

All information is provided for guidance only. Deviations may arise,

depending upon the paper used. Shortening or extending the development

time by up to 10% is possible.

Diluted 1+9  Eukobrom

In to the Darkroom.

The first thing you notice with this developer is it's lack of odour. The next is the colour of the liquid, a rich yellow. I decided to dilute at 1+9. Once done I poured the contents of the measuring jug into a tray. I would have used my up right paper processor but that already had fresh Ilford multigrade in it. Using the tray for the new developer would allow me to note how long it took for the image to start appearing.

The comparison.

I have several makes of light sensitive paper in stock. I chose three, the most obvious Ilfords multigrade, Fomaspeed Variant 311 and Kentmere VC select gloss, all resin coated papers. I went to these first as they are reasonable quick to process and give an insight into how the Eukobrom will perform. Before moving on to FB papers. (results to follow in another post)

The set up.

I chose a negative from a recently developed set of Agfa APX100. I set the height of the enlarger so it would produce an enlargement of 9 x 12 then set the easel to 8x10. I did this because the Kentmere paper I wanted to include I only had in 9x12, this would keep everything consistent.

Ilford multigrade RC  paper
 developed in Tetenal developer

 

 

The test strip was processed in the multigrade developer and it was indicating that the image would need to be dodged, if I wanted a picture I was happy with. I set the enlarger as follows lens F8, grade 3, exposure: The whole image was exposed for twelve seconds, the sky from the bridge upwards plus eighteen seconds and finally the sky from half way up to the top of the image plus eighteen seconds. I would produce two pictures on each paper all at the same setting. The developers temperature was set at 20C.

Ilford multigrade RC
 Paper developed in Multigrade

 

Results:

Both developers are advertised as neutral tone. To me this means they are subtlety on the cool side.

The differentiation started with:

• The Ilford paper when compared with the other papers in the test, has a slight warmth to it's tone when developed in fresh multigrade. The Eukobrom is slightly cooler in look with a more intense black and crisper whites giving it a bit more contrast.
• The Fomaspeed paper has a cooler look to it when developed in multigrade compared to the Ilford paper. The Eukobrom proved to be cooler looking again with more intense blacks and clearer whites again adding to the contrast.
• The Kentmere paper is known to have a higher contrast level to the previous papers mentioned maybe as much as a grade. When developed in multigrade the image had a muddy look to it indicating over exposure with a slightly warm feel to it. The Eukobrom processed image had a cleaner crisper look. Again the midtones had better separation making it look more like a moon light picture instead of over exposed.

Fomaspeed variant RC
 developed in Tetenal

 

Once you understand that Eukobrom adds contrast to the image possibly more so than the Hydroquinone it replaces. It is easy to allow for by reducing the grade you would normally use. The blacks are wonderfully rich giving the pictures some real punch. The mid tones have more separation than Ilford multigrade but the surprise is the brightness of the whites.

Fomaspeed  variant RC
developed in Multigrade

Personally the main questions yet to be resolved are its keeping qualities and whether or not the image will be warm when the developer starts to deplete.

Kentmere paper.
Top Row: exposed at grade three.
Right side Tetenal developer. Left multigrade.
Bottom row: exposed at grade two.

 

This is a nice developer to work with for prolonged periods as you do not get that developer smell lingering up your nose afterwards. Oh! It does look like OJ when diluted so keep it out of the reach of kids. It is a real gem and I will be ordering a bottle, it may even replace my favorite multigrade! Don't take my word for it try it for yourself you will not be disappointed.