Martin Rickards

The problem for us is the amount of custom manufacturing they did for e.g.Ilford and Kodak.At present they still have a way to go before they even know whether the proposed management buy out will get through the German courts.If it does, there's bound to be some interruption to production. At the moment I'd recommend keeping fingers and toes crossed.

The lens with the Opemus looks like an Anaret, made by Meopta and worth next-to-nothing IMO. The enlarger itself will only take up to 6x7 negatives, I believe, whereas the Fuji definitely has a 6x9 carrier included.

 

Opemus enlargers were about the lowest-priced available when new. Serviceable, but definitely built down to a price. I think the Fuji might well last you longer.

 

Anyway, the lens is the most important component, and that Anaret probably won't do justice to a reasonably sharp negative.

 

WRT f/2.8 enlarging lenses, it has little to do with brightness or printing speed. Most f/2.8 50mm lenses have a high-quality 6 element design. Whereas those with an f/3.5 or f/4.5 aperture are simpler 3 or 4 element jobs that almost invariably give inferior print quality. Condition, is everything though, so you need to get a clean sample that's been well looked after, but definitely not over-cleaned!

Having used both the Fuji and Meopta, I'd say the latter is better built and will prove more durable. I had to throw the Fuji away when the clamp holding it to the column failed. Meopta's Meogon lenses are very good. Only the Opemus 7 will accept 6x7 negatives; all others take a max of 6x6.

Although the general advice on enlarging lenses is El Nikkor, Rodenstock or Schneider, there are numerous others and any 50mm from Photo Cornucopia with 5 elements or more should be OK for 35 mm. I've got the Opemus enlarger with a colour head, but you B/W version comes with a filter drawer that you'll need for printing variable contrast papers. It's a sturdy rather than sophisticated enlarger.

One thing to be careful with is the lens mounting board which is domed in the middle. The dome is mounted upwards for 35 mm negatives and downwards for 6x6.

Thank you both.

 

I knew there was a reason I kept the toaster oven my wife acquired on Black Friday last year for $10. Unfortunately I forgot what I wanted to do with it and donated it to a charitable organization this summer...

 

I guess I will start by looking. The CO2 absorption sounds like the largest uncertainty.

 

Good news, (I guess) is that the only material stored in the garage was the 25# tub of sodium thiosulphate.

 

Won't be the first time I wasted money trying to save money....

The sodium thiosulphate will probably still be OK. It's sold as the pentahydrate salt, is very stable and its effectiveness can still be judged simply on an old film leader in case of doubt.

I use the Meopta Vipo timer. 25+ years no problems.

But why would you burn sodium carbonate to decomposition if it's the stuff you want?

 

Since no domestic oven heats to 400C, it's all a bit academic. However a domestic oven could be used to drive off the water-of-crystallisation and turn decahydrate into the mono or anhydrous salt.

Soda ash is routinely heated to much higher temperatures in e.g. glass manufacture (1500ºC) Also https://www.researchgate.net/post/Thermal_decomposition_of_Sodium_Carbonate

The domestic oven can also be used for converting sodium bicarbonate (baking soda) to sodium carbonate

...

If you heat sodium carbonate enough, you drive off the CO2, and get sodium oxide.

Then you can hydrate it back to sodium hydroxide.

 

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??? I can remember from my lab days using sodium carbonate in platinum crucibles and heating it to red heat to fuse samples. Sodium oxide was not formed.

Washing soda is usually, in England at least, the decahydrate and must be used at 286/106 x the rate of sodium carbonate anhydrous (soda ash).

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Spent developer reverts to coal tar and the alkali solution is neutralized by the chlorine which is an acid....

 

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Chlorine is not per se an acid. It's hydrolysis products: hypochlorous acid and hydrochloric acid are.

Strange as it may seem, the major use for rapid fixers (ammonium thiosulphate) is as a plant fertiliser.

Both color and B&W papers are now very fast. It isn't hard to get very short exposure times on smaller prints.

 

I have used equal C, M, and Y filters, as neutral density, in black and white printing.

 

I suspect that may also happen for small color prints, too.

My Meopta colour enlarger also has a neutral density filter of about two stops for just such a situation.

There are basically two types of widely used fixers based on sodium thiosulphate and ammonium thiosulphate. Fixing times are different for the two with sodium thiosulphate based fixers always taking longer. The sodium salt is usually supplied in crystals and the ammonium salt in the form of a concentrated solution. http://imaging.kodakalaris.com/sites/prod/files/files/resources/edbwf.pdf

In the late 90's I did a lot of printing for a wedding photographer and invariably used Ilfospeed RC grade 2/3. Fairly straightforward in use.However long exposure times from Ilford XP negatives.

It seems to be a six element enlarging lens and on the basis that if someone had set out to make a piece of crap, three elements would probably have sufficed, I'd say it's at least worth looking at.

@ Martin Rickards --

 

The light sensitive compounds used are iodine, chlorine, and bromine. These are members of the Halogen (Swedish for salt maker) family combined with silver. Ordinary sea water, or 3% solution of table salt will work just fine as a hypo clearing agent. More effective is a dilute solution of hydrogen peroxide which oxidizes and renders the fixer harmless. In lieu of table salt or peroxide, any of several common salts will alter the infusion rate of gelatin and pulp based papers. Most hypo eliminators work because the wash water is caused to better percolate within the material.

The halogens (iodine, chlorine and bromine, btw they are elements, not compounds) are not light sensitive (in the photographic sense), but it is the silver halides (iodide, chloride and bromide). It's like saying chlorine gas has a salty taste, whereas that's down to sodium chloride.

With respect to RC paper, the likes of Ilford, Foma etc buy it by the km ready coated and apply the emulsion to it..

Films and papers are covered with a coat gelatin in which is imbedded light sensitive salts of silver. There are three silver salts: silver iodine, silver chlorine, and silver bromine. When exposed to light these silver salts absorb light energy and this action reduces (splits) these crystals into their two component parts. In the camera or under the enlarger we don’t allow that much light to play. Our exposures are insufficient to reduce. However our exposures weaken the bond that holds the crystal together.

 

The developer solution is a reducing agent able to liberate metals from their salts. The developer differentiates between exposed and unexposed silver salts and reduces primarily the ones that received an exposure. Once reduced, metallic silver remains imbedded in the gelatin and the other components soak into the developer, which is mainly water. Unexposed silver crystals are not reduced, however, they will self-reduce if exposed to copious amounts of light. This action will occur without the aid of a developer. If this happens the metallic silver deposited by this self-reduction will darken the film or paper causing the image to fade.

 

To prevent this destructive self-reduction, we subject film and paper to a fix bath. This unique bath seeks unexposed and thus undeveloped (un-reduced) silver salts and dissolves them. As this is happening, the metallic silver that makes up the image is unscathed; it remains imbedded in the gelation coat we call an emulsion.

 

In order to work its magic, the fixer contains sulfur. Sulfur is an enemy of silver. Sulfur attracts over time, tarnishing by turning the silver yellow-brown. Eventually the entire image will become stained (flawed). To prevent we merely need to flush away all residual fixer with its sulfur.

 

Photo paper is mainly made from wood pulp, perhaps it contains linen. In any event, paper is comprises of a multitude of plant cells. These are little boxes that hold fluid. Thus the structure of paper makes it difficult to flush away the residual fixer. We must wash, in running water for 30 minutes, single weight fiber paper and 60 minutes for double weight. Less, we run the risk that the image will fade in time. During World War II it was discovered that washing in sea water (3% table salt) followed by a fresh water rinse did this trick in half the time. This is the basis for all the hypo clear solutions which are mixes of different types of salts.

 

Film fares better because it structures, no cells, allows for faster washing. Papers can however be waterproofed. This is a coat that prevents the paper from absorbing fluids. If so overcaoted, the paper acts much like film as to how it washes. Resins are substances extracted from trees. These substances have been used for centuries to waterproof cloth and even the hulls of ships. During World War II photo papers were resin coated to speed up the washing cycle. Today’s papers uses laboratory manufactured resins to do this deed. Fast washing is the chief advantage however, the resins can be embossed. This can simulate silk or matte or glossy. After the paper is coated and embossed, the light sensitive emulsion is applied. These are the same coats that can be applied to fiber paper that has not been coated with resin.

A couple of points. The silver halides are chloride, bromide and iodide; the chlorine, bromine and iodine are chemical elements.

RC papers are simply plastic coated (usually polythene), with no complicated laboratory processes.

Hypo clearing agent is usually sodium sulphite, not sodium chloride based.

I think Rodinal can be a bit unreliable because of its formulation. It uses unbuffered caustic soda as the alkali accelerator, which has three consequences: Firstly, a high pH solution softens and expands the gelatin of the emulsion, allowing grain growth to be larger and faster. Secondly, a high dilution to reduce said pH results in the alkalinity, and hence activity, becoming uncertain due to local water pH variation.

 

Thirdly, any very dilute developer runs the risk of 'burning out' its developer content and becoming a compensating developer, with consequent low contrast.

 

I suppose if you're very careful with its dilution and temperature, and only use distilled or DI water, then results can be consistent, but if you just use tap water the results might vary unexpectedly.

 

Personally, I'd rather use a formulation that has a buffered and well-regulated pH that doesn't depend so heavily on high dilution ratios.

It makes you wonder why it's still being used after being introduced in the XIX century:D

The number of people that swear by brand x, y or z would lead me to believe that there is no best enlarging lens. This may be due to several reasons, starting from there probably being some degree of quality variation among lenses of the same manufacturer, different levels of care of the lens, subjective opinions about what is good, enlarger set up etc.I'd hazard a guess that, as a general rule, most 3-4 element lenses are not as finely corrected as 5,6 or more element ones, though those of us who only enlarge to 8"x10" from 35mm would need a loupe to notice any difference if any. For those doing, say, 15-20x enlargements, the difference is probably noticeable.

You might try using a level to see if your negative stage is parallel to the baseboard (check in both dimensions).

I'm fairly happy with the alignment and I'm not posting my test results, but merely pointing out results published on a French website. Strangely enough a google search for the lens gives many French pages and very few English ones.

My own 35 mm enlarging lens is a Minolta 50 mm f2.8, which seems good enough for me.

I use an Opemus 6, which has no adjustments for aligning either the optics, negative stage or the illumination. All I can do is check that the projected image is square on the baseboard.

In fact, it was Meopta's 50mm f5.6 that won out as the best of them all, apo Rodagons included. That lens was discontinued even then, much to the annoyance of the writer. All lenses were tested at f8 and obviously that may not have been the optimum for all lenses.

PS. I meant to reply to arthur_gottschalk's post

Since writing about the Meogon, I have noticed on Photo Cornucopia that it is in fact a wide angle 6x6 cm lens rather than a standard 35mm lens. That may have something to do with the excellent results obtained using it for the smaller format.

Apparently ammonium thiosulphate is a useful fertiliser. It is sold generally as a 60% solution, but I have never been able to find any in less than bulk quantities.

With reference to the above post, I wrote thiosulphate, not because it is archaic but because that is how it is spelt in British English. Sulphur is also correct, as is litre.

PS If you don't like "spelt" either get a good British English dictionary.

google translator?

That gives the rather unhelpful "love rating".

I understand the first three standards on the graph, but what does "Cote D'amour C.I." represent?

I've got no idea. I'm not sure if it's some value for money ranking. However, even the discontinued lens with no price scored, so that can't be it. Google doesn't differentiate between "cote" and "côte":(

I would take that French magazine 'test' with a big pinch of salt.

 

As with any lenses, sample variation can be far greater than any design performance, as can operator error.

 

The bar graphs shown do not reflect what's stated in the text. For example; of the 80mm Componon it's stated 'distortion is not measurable (less than 0.1%)' and gets a score of 5, while of the Rodagon 80mm it says 'the distortion is at the limit of measurable with 0.05% cushion', and only gets a score of 4.

So, what is their limit of measurability? 0.1% or 0.05%?

 

Another lens with 0.1% cushion distortion only scores 3, the same as one with 0.25%.

 

There are similar discrepancies and inconsistencies between text and score throughout the article.

 

I know that if I was offered a Rodagon or a Meogon for the same price, I wouldn't be taking the Meogon.

As I speak French very badly, I can only state that in the introduction distortion of between 0.1 or 0.2 is considered the limit of measurement. My own opinion is that variances in quality between the same lenses are probably as great as those between some different lenses. If I were offered a Rodagon or Meogon, I'd try them both to see, but I doubt whether I'd be able to see much difference.