Fórum Open Photography Forums

𝗖𝗹𝗶𝗰𝗸 Here for 16 images and commentary: . . Once again, 𝗖𝗹𝗶𝗰𝗸 Here for 16 images and commentary.

Some while ago I adopted the term "photometric exposure" to mean the phenomenon (H) to which film and digital sensors respond, the product of the illuminance on the film/sensor and the time that it persists. I more or less "made up" this term. I have recently realized that all this time there has been a perfectly good SI name for that quantity: "luminous exposure". So I have just now changed my style practice to use the term "luminous exposure" for that property. I will try to use it... Read more

So two images for the day of Model Rebecca Lawrence (AKA BexLaw). She is wearing the Elemental Witch Goddess of Metal Costume. Full Costume and then what I call Stage 3 version.

As can perhaps be seen from some of my recent essays here, if we have a fixed and highly stable phtometric exposure (perhaps during testing of a camera), and the photodetector system exhibits some certain degree of read noise, the quantization that occurs during the initial digitization of the photodetector outputs affects the degree of "noise" we observe in the digitized output. If in fact the standard deviation of the read noise (its "measure") is fairly small compared to the quantizing... Read more

Light Painting tonight in Stratford, Ontario. Unfortunately it was a very quiet Sunday evening with virtually no one on the streets and very few vehicles passing by this location. But the skies smeared beautifully in this 20 minute exposure. My 10 stop, variable neutral density filter came in today from Amazon, and I was eager to try it out —— giving me the ability to start the exposure before the sun set using f8 with my 8-25mm f4 PRO Olympus lens with Live Composite mode in my camera... Read more

The quantization of photodetector output voltages (as the voltages are digitized) itself is the cause of "errors" in the representation of the voltages. But quantization also has an effect on the various sources of random noise (read noise, photon shot noise, dark current noise - but for conciseness I will from here on call that whole lot "read noise"). Here I will explain how that happens. First I will do a brief review of the probability density curve, which we will encounter in the... Read more

Quantizing error is the discrepancy between a value as represented in quantized form (typically in a digital representation) and the actual value. As this applies to the basic digital representation of an audio waveform, and especially in the telephone industry, it became common to speak of this error as "quantizing noise". This was principally done so that long-established ways to quantify noise (in the familiar sense of a random and presumably undesired component in a received audio... Read more

Some people think that 16-bit has more dynamic range (DR) than 8-bit. I've never fully understood that view ... for example 65535/0=infinity and so does 255/0=infinity, ergo it can't be just the bit depth that gives "more" DR ... and avoiding the division-by-zero by selecting say 1 as the lower bit level seems too arbitrary. However, THE ISO standard for DR is well-discussed here, thanks to Doug: http://www.dougkerr.net/Pumpkin/articles/ISO_Dynamic_range.pdf It's not certain... Read more

I have been dealing with serious health issues this year, but have used the opportunity to work on my robertwatcher.com website —— as well as hop out of the car on occasion to find things of interest to photography, such as these few shots around the Goderich harbour yesterday as a tug boat was aid a large laker to line up with the salt deliver shaft at the Goderich Salt Mine

So first been awhile, this is from a shoot last year. It was partially for my costume set, but due to circumstances the project was halted for a time. This image is of Belle Amelie wearing the prototype skirt from the Elemental Goddess of Fire. I have had two models wear it, was checking for how it looks before proceeding to modify it as planned for the eventual final version. I may still finish the costume as we have all the cloth needed. but circumstances got in the way of inspiration... Read more

Donald Norwood's initial quest was for a system that would facilitate the determination of the "proper" photographic exposure during the photography of a human face (head, actually) using the "key-fill" lighting technique, ideally allowing this to be done with a single measurement with an appropriate "incident light" instrument. In support of his approach to this, he ran an elaborate series of tests that showed, as the key light (with a certain fixed "potency" at the subject) was... Read more

I just realized I never posted this one here. So found out my newer camera will do a thing, in camera, so had to try it out. It is posted here in this sub-forum because obviously the model is not wearing much So apparently I can set my camera (Canon R5c) to do a multiple image thing. Up to at least 5 images. I kind of think I could do a better job using Photoshop combining multiple images into one, but still it is kind of cool thin to be able to do it in camera, even if it takes some... Read more