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Mike7

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  1. Like
    Mike7 got a reaction from fasteddie in Streetphotography (open thread)   
    X-T1, Canon FD 2.8/24mm, F4, 6 sec., ISO 200
     

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    Mike7 got a reaction from milandro in Streetphotography (open thread)   
    X-T1, Canon FD 2.8/24mm, F4, 6 sec., ISO 200
     

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    Mike7 got a reaction from Jürgen Heger in Streetphotography (open thread)   
    X-T1, Canon FD 2.8/24mm, F4, 6 sec., ISO 200
     

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    Mike7 got a reaction from rolf55 in Streetphotography (open thread)   
    X-T1, Canon FD 2.8/24mm, F4, 6 sec., ISO 200
     

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    Mike7 got a reaction from JD-Snaps in Streetphotography (open thread)   
    X-T1, Canon FD 2.8/24mm, F4, 6 sec., ISO 200
     

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    Mike7 got a reaction from PAE in Streetphotography (open thread)   
    X-T1, Canon FD 2.8/24mm, F4, 6 sec., ISO 200
     

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    Mike7 got a reaction from woodlander in Streetphotography (open thread)   
    X-T1, Canon FD 2.8/24mm, F4, 6 sec., ISO 200
     

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    Mike7 got a reaction from jerryy in Streetphotography (open thread)   
    X-T1, Canon FD 2.8/24mm, F4, 6 sec., ISO 200
     

  9. Like
    Mike7 reacted to BobJ in What is the difference between shaddows and dynamic range   
    It's not a stupid question Pranfeuri. In a nutshell then, here goes. Dynamic range is a term used in electronics. In a camera it is used to describe the brightness range from the deepest shadow tone that can be distinguished from noise to the brightest tone that can be recorded before the sensels become saturated and cannot convert any more photons. In ye olden days when I used film the equivalent was known as the films latitude. An analogue to digital converter is used in the camera to digitise the output from the sensor and can usually give a 14 bit wide digital output. Jpegs are only 8 bit so they cannot include all those tones. However 8 bits are enough to describe all the tones that a monitor, tablet etc can display or a that print can reproduce. Therefore we have the opportunity to compress the 14 bits into 8 bits using what is known as the tone curve. The algorithm in the camera does this for us but may need altering for some images. The DR and shadow and highlight settings in the Fuji cameras can be used to do this. Basically the DR settings underexpose so as not to blow the highlights and boost the mid and shadow tones to fit in. The shadow and highlight adjustments change the tone curve to make them darker or lighter as required. Of course if you use raw then you can decide afterwards how to fit the tones in. That is one of the main advantages of raw. With the latest sensors it's amazing how much detail can be rescued from the shadows before noise becomes a real issue.
  10. Like
    Mike7 reacted to bhu in What is the difference between shaddows and dynamic range   
    "Shadow" settings adjust gamma near the dark end of the luminance range. This is typically used to artificially increase luminance in low-luminance areas so you can see more detail in dark areas when the image is reproduced. Shadow enhancement can be applied to any photograph, even photo's taken with "DR" enhancement. Those settings usually just re-map gray levels. For example, gray levels 1, 2, and 3 may be re-mapped to gray levels 2, 4, and 6 making them artificially brighter.
     
    Dynamic range is supposed to be an increase in the sensor's range of counting photons. That is, if a pixel element in the sensor needs 10, or more, photons to be not-black and 10,000, or fewer, photons to be not-white (saturated), the dynamic range is 1000:1. Now, say that some new sensor may be able to read only 5 photons for not-black and can accept 50,000 photons for not-white resulting in 10,000:1 dynamic range. True dynamic range is a function of the photo-receptors on the camera's sensor.
     
    Please note that dynamic range has nothing to do with bit-depth - the number of gray levels. Bit-depth simply divides the sensor's operating range of detectable luminance into gray levels. A sensor with 1,000,000:1 dynamic range can have an 8-bit per color conversion or a 14-bit per color conversion but you should expect the 8-bit to show gradations, or lines, where the photon count breaches the next gray level. Spacial dithering can help smooth "chunky" gray levels but the best way is, obviously, to add more bit-depth, which divides the sensor's luminance range into finer and finer slices.
     
    There are ways of fudging this, though, so beware of the difference between true dynamic range and "features" that call themselves Dynamic Range, or DR. Fujifilm has been adjusting gain in pixel elements so that, even if the element's range is small, the range can be moved, shifted, so that some elements are "tuned" to be more sensitive and some are "tuned" to be less. This technique effectively increases a picture's dynamic range at the cost of... spacial dithering; that is, half the pixels scattered throughout the image may be exposed more, leading to blooming in bright areas just to capture detail in dark areas, while the other pixels might be less exposed to preserve detail in bright areas at the cost of losing detail in shadows.
     
    Using a DR setting sprinkles darker pixels in with brighter ones to (theoretically) increase the dynamic range of the picture (but not individual pixel elements). (I said, "theoretically," because the increased dynamic range must be saved in the picture, then reproduced on some media capable of showing it.) There is nothing inherently wrong with this approach and it can actually aid in giving a photo film-like grain.\
     
    Of course, there is another way to increase dynamic range: Take two photographs with different exposure settings and overlay them. That is the common "HDR" stuff you read about. Typical HDR photography increases dynamic range by using temporal dithering (in a very simplistic sense).
     
    Shadow enhancement can be applied to any photograph, even photo's taken with "DR" enhancement. Those settings usually just re-map gray levels. For example, gray levels 1, 2, and 3 may be re-mapped to gray levels 2, 4, and 6 making them artificially brighter.
  11. Like
    Mike7 reacted to BobJ in Micro-contrast - What is it?   
    Micro contrast has nothing to do with colour. A lens with high micro contrast can distinguish between increasingly small variations of tone at high frequencies. It is about resolution, which is not the same as sharpness. An image can look sharp but have low resolution. All lenses are optical compromises. A lens with high macro contrast and low micro contrast can appear sharp despite not being able to resolve fine detail. A lens built for high micro contrast can show fine detail but can produce dull and lifeless looking images. In practise a lens designer has to balance these two qualities together with many other lens characteristics. Leica and Minolta, who worked closely together for a while in the pre-af era, made low macro contrast lenses that could resolve fine detail and had a lovely subtle tonal reproduction. What the designers did was to boost the MTF figures at finer than 60 cycles at the expense of the 10-30 cycle range. A decade ago David Kilpatrick wrote a very illuminating article called "Historical Perspective on Minolta Lens Design Philosophy". I have a hard copy of this but I don't know if it can still be found online. In it he discusses some of this together with coating decisions made to help give contrast and colour consistency (lens colour was much more important in film days for obvious reasons).
     
    Nowadays with exotic glasses, aspherical elements and design methods that were not available in the 70s and 80s, lenses can be made with less compromise but differences are still there. A couple of years ago I was lucky enough to attend a factory tour at Cooke optics in Leicester. Their hand built lenses are used for many feature films and TV dramas and are famed for the "Cooke Look". It's difficult to explain but involves smooth tonal transitions and beautiful bokeh. Interestingly they told me that they are able to design for the look in the design software. If you have to ask how much they cost you can't afford one! The TV companies mostly hire them. The feature film people have such big budgets that they are not a significant cost to them. Have a look at their website, it's quite interesting. www.cookeoptics.com
  12. Like
    Mike7 got a reaction from George_P in Streetphotography (open thread)   
    X-T1, Canon FD 2.8/24mm, F4, 6 sec., ISO 200
     

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