Mixing box vs. condenser

Dongrappo · 2020-03-04T17:32:29+00:00

Liebe Leute Nach so vielen Informationen im Netz, hier nun mal ein eigener Versuch mit Bildern für interessierte. Es geht um das Thema Vor- und Nachteile v...

Dongrappo

Hi everyone, With so much information online, here’s my own attempt at a post with photos for anyone interested. It’s about the pros and cons of condenser vs. hybrid box units. :arrow: If you can’t be bothered with my long-winded explanation, you’ll find a link to the sample photos towards the end of the text! :sleepy: At first, I only had condenser units. With the Krokus 69s, for example, whether with or without frosted glass in the filter drawer, I couldn’t really spot any significant difference, apart from the longer exposure times. My old Kaiser units also produce almost identical results. Even with the Kaiser model featuring a colour head – i.e. with a mixing box – the outcome is no different. After the mixing box, the light is also directed via condensers. No real difference there either; it’s perhaps, maybe, possibly a tiny bit softer?!?!?!? Perhaps?!?!?. Now, however, I’ve got a few more Durst units (yes, yes, I’m already ashamed :blush: ), all fitted with colour heads. The M605 colour head has ‘only’ a mixing box, so it works entirely without a condenser, and I tested it yesterday with the Krokus 69s without the ground glass in the filter drawer, as I wanted to see for myself in practice just how the differences really are. As I’m still fairly new to this, i.e. a beginner, it’s possible I’ve overlooked some key points. If so, please let me know. But be kind to me! :-) Test setup: Last year I developed some 35mm Agfa Delta 100 films in Caffenol tank development (which is what I’ve almost always done in recent years). Two films from two different cameras, developed simultaneously in the same developing tank, and both showed some scratches, dust and dirt in the emulsion layer afterwards. Annoying, and I don’t know why or where it came from. But good for the test, as mixing tanks are described as much more forgiving when it comes to dust and scratches, whilst condenser tanks are real ‘pain in the neck’ in this regard, though they produce sharper results. For the Durst, I only have the 35mm frameless mask (if any of you still have accessories for the Durst, please do get in touch!!) and I cleaned everything as thoroughly as possible beforehand. Then I determined the exposure and selected the gradation. With the crocus, the task was now to achieve a similar gradation and adjust the exposure. That’s not as easy as it sounds! I enlarged the negative onto new Fomaspeed Variant 311 Glossy 17.8 x 24 cm Durst gradation at (max. 130) filtration = I then opted for Magenta 80, which is supposed to correspond to almost gradation 4 according to the Foma data sheet. (M90 = Grad. 4). For the crocus with a glass mask – cleaning and checking for dust on which took quite a long time, as always – I then loaded the filter drawer with an Ilford Multigrade filter, gradation 3.5. As I’ve read time and again that condenser units work a bit harder, I wanted to use that very hardness to bring out the scratches and dirt a little. Now I’ve specially dug out my good scanner from storage and connected it, then made one image as an overview at 150dpi, (the slightly crooked one is from the Durst, the straight one from the Krokus) and, in addition, two high-resolution 600 dpi sections of the enlargement: firstly, of ‘A’, a spot with a severe scratch in the coated layer, and secondly, of the foreground (asphalt), where I think one can clearly see the sharpening effect of the texture and make a comparison. Both enlargements were taken with the same lens, a Schneider Componon-S 2.8/50mm at f/8, and I took great care to achieve the optimum sharpness using my Paterson grain focuser, whilst also ensuring that no vibrations or similar factors influenced the results. I also found it interesting that with the Durst 100W colour head I had an exposure time of 6 seconds, and with the Krokus 69s 150W opal lamp and condenser, 8 seconds. I also find it very interesting – though this isn’t really visible on the scans, if at all – that the ‘Durst image’ has a slightly warmer grey tone! I developed all the prints thoroughly in Rollei RPN developer. The ‘warm tone’ could also be due to the fact that the Krokus version has a slightly harder gradation; the light distribution is different – see also the vignetting on the Durst, particularly noticeable in the top right-hand corner. But as a poor man, I couldn’t bring myself to make another print of that size from a scratched negative! Even though it does make me itch a bit to work on it more precisely, I find the result simply enlightening for myself and sufficient to make a few decisions and gain some knowledge. And also to get unnecessary thoughts and concerns out of my head. I learn a great deal from testing things out myself. Even if I have to learn the hard way when it comes to materials. I just want to get out of that rut at some point! ;-) Of course, a good picture doesn’t really care how or with what it was taken and enlarged. Although, in my opinion, it really depends on the subject and the application. With subjects that have a lot of detail, it simply makes sense to realise them as optimally as possible in terms of quality, technique and format. Yet many simply taken pictures have also managed to impress me greatly. Even ‘mistakes’ can be what makes a picture worth seeing and special. The trick is to be open to these “gifts” and to be able to recognise and accept them. At least for “control freaks” like I often am, it’s a learning curve. But things are getting better and more relaxed, yeah! Be that as it may, perhaps this post can serve as a help to those who harbour similar questions and concerns. I’ve also been able to let go of some of my own thoughts, as I’ve found helpful explanations online or in books – usually accompanied by examples. Because I M A G E S speak... how did that go again? Warm regards from Bremen Werner

Olivinyl

Hello Werner, You’ve been fiddling with the exposure settings and trying out scans that don’t really tell us much. I don’t want to put you down or dampen your enthusiasm for experimenting – no, that’s not what I want. I just want to give you a few basics to work with. I’m happy to be corrected, of course, if I’ve said anything wrong. There are three common types of enlarger: - Condenser/double condenser - Mixing box - Mixed light (combination of condenser & mixing box) There are various light sources: - Opal lamp - Cold light reflector (halogen) - LED - Cold light (e.g. fluorescent lamps) Each type of enlarger requires negatives developed differently (approximate guidelines – personal preference regarding image rendering also plays a role) Condenser: Soft negatives with a gamma of approx. 0.55 Mixed light: Medium-contrast negatives with a gamma of approx. 0.60–0.65 Mixing box: Negatives with a gamma of approx. 0.70 The higher the gamma value, the longer the negatives must be developed (the density curve becomes steeper) If the gamma value is correct, i.e. the development is properly adjusted to the enlarger type (as is the film exposure: i.e. actual film speed – not box speed) and a reasonably well-defined print in grade 2 with decent shadow detail and sensible highlights is possible. Every type of light source produces a different light; even an old halogen bulb requires a different paper gradation than a brand-new bulb. LEDs behave quite differently again from opal or cold light. So here, the gradation must always be adjusted. The light from a condenser enlarger is the most directional and also the ‘hardest’, and therefore requires softer negatives, which, due to the shorter development time, also have a speed reduced by approximately 1/3 stop. These negatives are also ideal for users of affordable ‘home scanners’. These enlargers have the property of making scratches and dust stand out more due to the directional light, as well as the film grain (as with scanning). The mixed-light enlarger casts almost undirected, very soft light onto the negative and acts like a soft-focus filter, but the negatives must be harder. The mixed-light enlarger combines both characteristics – I prefer such an enlarger, for example. See also: Callier effect Furthermore, you mention a Caffenol development – a great little experiment, in my opinion – which also has a certain merit. Unfortunately, the processes involved in Caffenol development are not 100% repeatable and, regrettably, do not have consistent results. There are many variations. It is simply difficult to make comparisons between several devices that operate completely differently and require different source material. Furthermore, it is not particularly helpful to use a negative that is very likely not optimally developed and cannot be used for such comparisons. Ideally, one would use a test negative (greyscale wedge – does not need to be calibrated) or at least a precisely exposed negative containing a test chart, which is also optimally developed and where the ‘negative hardness’ – the gamma – is known. On the subject of negative development, an article by Otto Beyer: https://www.fotografie-in-schwarz-weiss.de/sw-fotografie/filme-eintesten/36-kurzanleitung.html ...he has also published a very accessible paperback on the subject – well worth buying! Callier effect: http://zonevi.dk/junk/?page_id=62 I don’t want to discourage you from continuing to experiment, but unfortunately a proper comparison isn’t really possible as there are simply too many variables. Best regards Oliver

mattes

To be honest? It doesn’t really matter what you use to enlarge your negatives. You can produce a print from any good-quality negative using any enlarger. Whether a print has good sharpness or is out of focus is determined at the moment the photograph is taken. As well as misfocusing, camera shake is the main cause of out-of-focus prints. In fact, depending on the light path of the enlarger, there are differences in the image quality. However, this is usually insignificant. I used to enlarge with condenser units for years and then switched to a mixed-light head because of the lower ceiling height in my new ‘workspace’. It makes hardly any difference. Perhaps the only difference is that the edges of dust particles appear slightly softer in mixed light. Scratches and dust are always a nuisance, regardless of how the light hits the negative. It is said that softer mixed light makes dust and scratches less noticeable. That is true, but ‘less’ is still ‘less’ and not ‘none’. Negatives free of dust and scratches are better. Matthias

Dongrappo

mattes wrote It’s said that with softer, diffused light, dust and scratches are less noticeable. That’s true, but ‘less’ is still ‘less’ – it doesn’t mean they disappear completely. Matthias

Yes, I’ve come to that realisation too, but I wouldn’t have been able to put it so beautifully! I really like your sentence and thank you for your comments. Yet somehow the gradient effect is quite different, and with Durst (mixed light), I can filter 1/2 to 1 stop harder than with Krokus. Though you can’t really compare the filters either – Ilford versus colour mixing head. I’d also tested without filters on the same paper. Hmmmm?!?!? There was still a clear difference. So far, I get the impression that the different effects can actually be put to good use for ‘suitable’ subjects, as I’ve read that some old hands – and probably newcomers too – do. So, for those who have the luxury of both systems. It’s just that if I had to stick to one piece of kit, the decision would be a bit tricky. Typical Homo Consumens with his real-life problems! :-D But you’ve hit the nail on the head in saying that a good picture will remain a good picture with either system! I know that’s exactly the same in music production. There are so many religious wars there too!