sander_pronk

I use firefox 1.0.6, with flashplayer 7. The problem appears to be

html rather than flash.

It sounds like one of the coupling prongs on the lens or on the cameras are off. There are three couplings between the lens and the camera: one controls the opening and closing of the diaphragm during exposure, one indicates how many stops the lens is closed down, and one appears to tell the maximum aperture to the body.

If it's that one that is off (it's the topmost coupling lever) then there's no real problem: you should still be metering correctly and varying the aperture on the lens should also vary the measured exposure time. The only thing that is off is what the viewfinder shows as aperture.

If the two bodies show the same apertures, it's likely the coupling levers in the lenses are off; you might try to fix it yourself (by bending the topmost lever in the lens) if it really bothers you. It doesn't affect exposure at all.

You probably have a camera that has a 3/8" tripod mount, instead of the standard 1/4". (both hardly European, btw.) You'll need a little thing called a 'reducer bushing' that you can get at any photo store and probably most hardware stores, for $1-$2.

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<a href="http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=99797&is=REG"> this</a> is what it looks like.

All data (about 100 pictures and all kinds of measurements) had to fit into 3-5 megabytes, because that was about the maximum they could transmit during the 'listening time' of the Cassini spacecraft.

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See this <a href="http://news.bbc.co.uk/2/hi/science/nature/4175099.stm">BBC news article where they mention 'three floppies worth of data'</a>.

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Fitting all those pictures into such a small transmission (most probably without resorting to lossy compression) would get you low-res, fuzzy images.

Again, I don't really think that irregular placement is going to help aliasing problems: another example is the grain aliasing seen in film scanners. While the sensors there are regularly placed, the image consists of an irregularly placed collection of grains, the size of which can be exaggerated wildly if they're around the size of the inter-sensor distance.

I suppose you're right in thinking that irrregular sensor placement will probably help against the very regular moire effects. I don't have a digital camera so I don't know how much of a problem this is in real life. You'll still have to have some kind antialiasing filter though because of the aliasing effects that would show up as excessive graininess.

I was under the impression that apparent film sharpness was caused less by the ability of (B&W) film to show abrupt density changes than by adjacency effects which cause an 'unsharp mask'-like illusion of sharp borders.

uhm.. the second paragraph wasn't very clear:

Randomly distributed sensors still have a surface area, which means that to pack them together on the sensor (as closely as possible) without overlap, there is a 'preferred' distance between two sensors: around one sensor diameter away from each other. This preferred distance will cause aliasing on that scale.

A randomly distributed sensor array wouldn't help reducing aliasing artifacts; it would just make it slightly more difficult to produce a good antialiasing filter.

Randomly distributed sensors still have a surface area, which means that to pack them together on the sensor (as closely as possible) without overlap. This implies that there is a 'preferred' distance between two sensors: around one sensor diameter away from each other. This preferred distance will cause aliasing on that scale.

You could do an experiment yourself. Go into a room with a finely patterend carpet with high contrast between light and dark. Go stand in a corner and look over the carpet. At certain angles of view (between the carpet and your direction of sight) parts of the carpet will begin to 'move'. This is an aliasing effect caused by the 'sensors' in your eye, which are (I suppose) randomly distributed.

Thanks Fred and Antony,

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The Canadian Post website seemed to have different options for sending mail; ranging from '4 day delivery', to '8-9 day delivery' and 'normal delivery'. I was getting worried that the Contax RTS II I bought off Ebay yesterday would be in the mail for 4-5 weeks if I sent it through standard mail (my books were in the mail for 6 weeks (!) when I moved from the Netherlands to California).

Regarding the Scan Dual III: it seems (to me) that this scanner suffers from massive grain aliasing problems with conventional 400ISO films (HP5+ and TriX). Slightly underdeveloped T-grain films, however, scan very well.

I've been using Delta 400 in XTOL 1+2 (13:00 at 20C) and the results have been good (very sharp; detail to the individual pixel level, with reasonable grain). Neopan 400 has slightly less grain, but is a little less sharp; TMax 400 seems a lot less sharp and I don't like the tonality.

Any 100 speed T-grain film should give you very good results with this scanner (practicaly no grain and very sharp scans). I liked the greys from Fuji 100 Across most.

I'm under the impression that the exact film+dev recommendations are different for each scanner model and vary according to taste, so you should try for yourself.

I could post some examples if you want, so you know what you can expect from scanning B&W.

The price of the tokina, if used, seems a bit high. I would think $200 is more realistic. As a portrait lens, the tokina is really as sharp as a previous poster mentioned; I have it and it seems at least as sharp as my Zeiss lenses. The bokeh, however, is less smooth (but still not bad) and the colour of the slides made with it has a slight tendency to be more cold compared to those made with the Zeiss lenses. I'm now trying whether a skylight filter corrects this, but if you shoot print film you won't be able to see any difference.

Both macro lenses are also big and heavy compared to the 85mm. Zeiss; the tokina is heavier than the 135 Sonnar.

I don't (yet) know about the 100 speed films, but for me, the Delta 400 scans beautifully. I develop in XTOL 1:2 (13 minutes at 20C) and the results are extremely sharp (at least as sharp as my scanner can resolve, a minolta scan dual III, 2820 DPI) with fine grain (just a bit worse than 100 ASA slide film) and great tonality.

TMAX 400 was not nearly as nice; I think it may be an aliasing issue so the exact resolution of your scanner probably has a lot of influence on the resulting scan.

Probably the best you can do is try a 24/36 exp. roll of each for yourself before you buy another 100' roll.

Here's a sample at full resolution.<div></div>

This is what the '*' button (partial metering) does. It meters the light in the central sensor (there are 7*5=35 sensors so you can use it as a kind of spot meter) and remembers the exposure value for about 4-5 seconds. You can then focus by pressing the exposure button halfway.

Sander