rivi

Since the dots are black on the neg (white on the pos), it cannot have been anything preventing development, to the contrary. When loading the reel, might some drops of developer got on the film, so that these are overdevelopped spots?

I have a K20D, and when it comes to sensitivity vs. noise I'm very satisfied. Check <a

href="http://www.riviclaudia.de/gallery2/main.php/v/test/">these</a> for in-camera converter without any

postprocessing, and

<a href="http://www.riviclaudia.de/gallery2/main.php/v/observatories/paranal/night/">those</a> and <a

href="http://www.riviclaudia.de/gallery2/main.php/v/sylvjulian/?g2_page=10">

those</a> for final results converted from DNG. All the files have EXIF data available from the little camera

symbol in the individual frame view,

Some practical advice: As timing is important, I used to have (I'm digital now) the solutions in the amounts I would need in beakers ready and at the right temperature. The solutions that can be re-used can be poured back into their beakers. It is awkward to handle that through bottlenecks when you know the time is running. You can do the bottle-to-beaker and back part when you have time then. Even when you have time, a funnel or two is a big help. Before using some part of gear, like a funnel, with another solution rinse it. Chemicals wil last longer this way.

"Arista Premium Liquid Film Developer 32 oz. (Makes 2.5 Gallons) $9.99"

"Arista Premium Odorless Liquid Fixer 32 oz. concentrate to make 2.5 gallons $10.99"

 

If you don't want to make the full amount in one go, which is unpractical with 2.5 gallons unless you shoot a lot, you'll need a precise, and I mean "precise", scale for the chemicals. That's why I used to use liquids rather than powders. Some experience in practical chemistry, i.e. preparing solutions etc. would be helpful. Some other chemistry gear as well: A measuring cylinder in the size you want to prepare solutions that need precision (like developer). Some beakers for other solutions, like stop bath, fixer, etc. And don't forget plastic gloves, you'll have brown fingers otherwise, also hydrochinon, a common developer chemical, can cause allergies.

Hmmh, seems I got stuck at B.J.'s step 3.

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PS: So, to go to higher sensitivities means to improve the quantum efficiency, while at the same time keeping the noise low. To go to lower sensitivities means either to lower the quantum efficiency (but this lowers the max sensitivity as well), or increase the full-well capacity of a pixel. The full well capacity is set by pixel size and voltage. "size" is he ground area of the bucket, "voltage" sets how high it is. The bigger a pixel, the more capacity it has in holding electrons. The smaller a pixel, not only its capacity drops in principle, but the maximum voltage you can apply is lower, as otherwise the pixel may fuse a short circuit across it (less distance between electrodes -> lower voltage needed to fuse).

Yep there is. I just posted this (similar, not exactly) in another thread, but I think it fits here just as well:

 

The higher(lower) ISO ratings don't change anything on the sensor when it captures the light. It only changes the setup of the readout converter which is called "gain". That means how many electrons are counted as one ADU. The photons fill up a sensorpixel like a bucket. With the same number of photons, it always gets the same number of electrons. The ADU converter basically takes out the water with cups and counts the cups. The cup count is what goes int the RAW-file. The gain (and thus the ISO settings) changes the size of the cups. Whe the bucket is full, there's nothing you can do about with the gain (ISO setting).

Chile: Fjords and glaciers in the south (even antarctica, but that's more than four days), desert in the north, Andes in the east, Pacific in the west, Volcanoes and forest hills in the middle.

The higher ISO ratings don't change anything on the sensor when it captures the light. It only changes the setup

of the readout converter which is called "gain". That means how many electrons are counted as one ADU. The

photons fill up a sensorpixel like a bucket. With the same number of photons, it always gets the same number of

electrons.

 

The ADU converter basically takes out the water with cups and counts the cups. The cup count is what goes int the

RAW-file. The gain (and thus the ISO settings) changes the size of the cups. You may aks "why not always use

small cups?", and the answer is that the raw-coverter can count only 16000 (that's a 14 bit converter) or so cups

at a single go. If there are more in, it just gives out the max number it can count. Converters with more bits

are expensive and slow.

 

If there is a random contribution to the amount of water, small cups are more sensitive to it, i.e. the number of

small cups cahngs more than the one of big cups. Most important random contributions in sensors are readout-noise

(the same level per readout but increasing with temperature), dark current (increasing with exposure time and

temperature), and in really low light the light itself, i.e. photons come in with a statistical element (plus

minus the square root of their average total number). The latter noise is absolutely unavoidable, and ths is why

a setting at ISO 6400 can in principle not be as good as ISO 100.

Well, CCDs work linear, so a CCD with a 14 bit converter and sufficient full-well capacity is indeed capable of 14 stops. It is actually not really a problem to build CCDs with that dynamic range and more (much more), the problem is rather that the readout times increase drastically with converter bits, which is not suitable for DSLRs.

 

While it is of course possible that the in-camera converter scales up the converter bits into a higher number of bits in the RAW frame, this plainly makes no sense. I know for sure that 12bit RAWs came directly from the sensor ADU converter, because the 12bit CCD converters were/still are industry technical standard. I admit I'm mot so sure about 14bit, though.

 

That said, there is normally a ground level (called bias) that takes away several stops, as well as noise, in which the first few EVs drown, so you won't get the full range.

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Ups, it is the Helix M27, not the Ring M57. But then....

What really matters is that both surfaces of the filter are plane-parallel (they don't need to be precisely parallel to the sensor plane, actually, as a slight overall tilt just displaces the image by a few pixels), and that the reflectiveness of each surface is low. Plane-parallel is impossible with gel (cellophane), but already resin-filters offer quite some decent level of that. To reduce the reflectiveness you'll need coating.

Those "35 fantastic HDR images" are a bit more than HDR. They pull (overpull) all triggers PS has to offer.The

sky in the third (the palace) is actually taken from a Hubble Space Telescope image of the Ring nebula M57, for

instance.

I suppose you don't mean a sheet film studio camera by <a

href="http://www.photo.net/equipment/large-format/choosing">"Large Format"</a>, but rather a <a

href="http://www.photo.net/equipment/digital/sensorsize/">"full size sensor"</a>? If so, there are indeed differences

(ok, in real large format vs. digital there as well), the most important of which is a different <a

href="http://www.photo.net/learn/optics/dofdigital/">depth of field behaviour</a>. That said, however, I wouldn't be

surprised if going to "large format" has more to do with psychology in I-don't-dare-to-estimate-how-many cases.

 

Actually, if you ever go to full size sensor, you'll find that your lenses most likely won't last, since their

image circle won't cover the full size sensor.

"There is no universal definition really for say Red Green and Blue" The response curves of the human eye are

actually quite well known. It is just that camera manufacturers don't really care, since they are not out for a

scientifically correct reproduction. If they were they had to use science grade CCDs with pretty expensive

filters. They usually, both in film and digital, are out to a present a pleasing picture in the end, and already

film was tweaked very much towards this response, except for some science emulsions.

 

For the two pictures I can tell that the lower one is probably more true to the actual conditions, since the

shadowed part is really blue because it is lit by the blue sky. But then, if you like the other one more there's

nothing wrong with it.

"HDR now means I have to lug a tripod around all the time, with angle viewfinder and cable release etc etc.. More expense, more kit, less happy." Why? The same way you can use a stitcher to stitch a panorama, you can use it to align frames of the same field. As long as the subject hasn't moved, the movement of the camera is no problem. Of course you have to stay within traditional no-shake-limits.

Was likely wind moving the upper branches of the trees. You can check that the individual frames to be sure. In the final one, you'll have to clone it out.

There it is, <a href="http://www.pentaxforums.com/forums/pentax-dslr-discussion/27805-k20d-dust-alert.html">second answer</a>: green mode and AF-s

Could also have been the focus mode.

Hi, had the same problem. Think it had to do with the camera mode. Don't remember right now the details, but set it in automatic mode, Tv and Av and try in all of them.

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I should add that these are strongly directed towards arts. Photography as a trade is taught (in Germany) by senior photographers through an apprenticeship system, but this education is no longer mandatory to open a photography business.

Most German public art schools ("Kunsthochschule") will have photography. There are fees, though, but they are

the same as for all public universities, and comparatively modest. You typically wouldn't study plain

photography, but more universal concepts, like "visual communication", "media design" etc.