| » Forum Index » Straight photography and off-topic » Topic: Service Station, Gundagai, NSW, Australia |
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Posted on 10/09/24 09:00:12 AM |
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Ben Boardman
Printing Pro Posts: 552 Reply  |
Service Station, Gundagai, NSW, Australia
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Posted on 10/09/24 09:48:04 AM |
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Frank
Eager Beaver Posts: 1673 Reply  |
Re: Service Station, Gundagai, NSW, Australia
Nice night shot. |
Posted on 10/09/24 10:45:52 AM |
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GKB
Magical Montagist Posts: 3858 Reply  |
Re: Service Station, Gundagai, NSW, Australia
Very nice Ben. If I may critique the image, and assuming that I am not teaching my grandmother to suck eggs; I can see that you didn’t have this option open to you and it may sound counterintuitive but, with night shots, the more lights you have in the picture the better as a rule. Use as small an aperture as you can. This will give you light trails from passing vehicles and people moving through the scene will be hardly recorded. Small apertures can also give those nice starbursts from point light sources. _________________ Why is it that all the contestants in the ‘Miss Universe’ contest are all from Earth? |
Posted on 11/09/24 10:41:10 AM |
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DavidMac
Director of Photoshop Posts: 5293 Reply  |
Re: Service Station, Gundagai, NSW, Australia
I am a teeny bit confused Gordon. 
Same thing different terminologies. I take it, when you say small aperture, you mean small physically not numerically? What, as a cinematographer, I would call a high aperture? 
This would imply the necessity for long exposure with the effects you are describing. _________________ The subtlety and conviction of any Photoshop effect is invariably inversely proportional to the number of knobs on it ....... |
Posted on 11/09/24 3:18:36 PM |
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Frank
Eager Beaver Posts: 1673 Reply |
Re: Service Station, Gundagai, NSW, Australia
Can get confusing in terminology: f16 = small aperture, large # f2.8= large aperture, small # |
Posted on 11/09/24 5:33:36 PM |
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GKB
Magical Montagist Posts: 3858 Reply |
Re: Service Station, Gundagai, NSW, Australia
David Yes small physical size larger number; the ratio of focal length to aperture diameter. _________________ Whatever you do in life do it with the enthusiasm of a 4-year old in a Batman suit. |
Posted on 11/09/24 5:48:26 PM |
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DavidMac
Director of Photoshop Posts: 5293 Reply |
Re: Service Station, Gundagai, NSW, Australia
Yes. Exactly. Ironically, to stop down means to raise the number. To further confuse, in cinematography f16 (a small aperture) is referred to as a high aperture and conversely F1.8 (a large aperture) is referred to a low aperture. Even worse is the word 'stop'. It gets used wrongly a lot with the terms 'large stop' and 'small stop' often being confused and even completely interchanged as, with inexperienced users, it is not always clear if the word 'stop' is being used to describe the aperture itself or its f number. _________________ The subtlety and conviction of any Photoshop effect is invariably inversely proportional to the number of knobs on it ....... |
Posted on 12/09/24 12:20:25 PM |
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DavidMac
Director of Photoshop Posts: 5293 Reply |
Re: Service Station, Gundagai, NSW, Australia
I think I have given a false impression that I didn't quite understand all this. As the son of a photographer who grew up with photography from boyhood and a professional Director of Photography for fifty four years, I think I actually probably do. 
My question was because I wasn't sure what frame of reference Gordon was using. Whether he was referring to physical aperture or aperture number. Given that Gordon is also a hugely knowledgeable photography professional with many long years of experience behind him that was really stupid of me. I should have known better. Sorry Gordon! 
But it gives rise to a question ........ The bit that follows is rather long but if you are interested in photography I think you will find it interesting. One day on set, many years ago, a Director asked me "David, what does the f in f stop stand for?". I thought at first it was some kind of trick question that would have a jokey answer with a giggle for the crew at my expense. But it turned out he was completely serious... he really wanted to know. At this point I froze as it slowly dawned on me that I hadn't a clue! It was something I had quite simply accepted and never thought about. I turned to my first assistant (or focus puller as she was known) whose job it was to continuously adjust the focus as the camera and actors move around. It's a hugely demanding job and requires a real knowledge of different lenses with their different depths of field and how aperture affects them. On occasions, for example, she would even warn me after rehearsals how much light I would need to provide by calculating in advance the f stop needed to keep, for example, two separate actors both simultaneously in focus as they moved independently through the scene. Clearly she would know the answer to the Director's question. (Incidentally when I first started using her in 1972 she was only the second woman ever to be admitted into the camera department in the UK and I came in for some criticism for making her my first choice assistant. Now, thank God, such silly restrictions are all gone and it is completely open.) One look at her face told me she was in the same state of panic as I. We neither of us had an answer! So I did what we all do in such situations .... ask someone who does. I called a man called Bill Wodehouse who worked for Samuelson film service in London. Back then, Samuelson were the largest suppliers of professional cine equipment in the world (later acquired by the American company Panavision). He was their lens specialist who sourced lenses of every type from all over the world, tested them and adapted and refitted the best for Samuelson's cameras. He was well known throughout the British industry as "Bill the Lens". Lenses were his 'babies'. He loved them! If anyone was going to know it was him. So before I move on to Bill's answer ... do any of you know what the f stands for in f stop? Here's the answer (inasmuch as there is one) from Bill plus a little bit of modern research on Google ........ In the very early days of photography there was no control of how much light was transmitted through a lens. They simply let through what their physical diameter dictated. In the mid eighteen eighties a man named John Waterhouse introduced a system of metal plates, each with a different sized hole in them, that could be inserted into a slot in the side of the lens and used to control the amount of light passing through. Because they 'stopped' some of the light they became known as 'Waterhouse stops'. This is commonly accepted as the origin of the word 'stop' in relationship to aperture. At this stage the relationship between the physical diameter of the lens and its focal length was not properly understood and the diameter of the hole in the stops and the amount of light they allowed to pass though was somewhat arbitrary depending on lens make and type. There was no absolute measure. Over time this changed and a formula evolved allowing for a unified calculation of transmission that could be applied to any lens. The f-number N is given by: N=f/D where N is the f-number, f is the focal length and D is the effective diameter allowing light through. This system was championed in Gt Britain in the late eighteen hundreds by John Hodges who called it the 'fractional number' system. It became normal usage to write the aperture number N preceded by "f/", which is a mathematical expression of the effective diameter in terms of f and N. For example, if a lens's focal length were 100 mm and its effective diameter were 50 mm, the f-number would be 2. This would be expressed as "f/2" in a lens system. The aperture diameter would be equal to f/2. Over the years this became shortened and simplified to simply f2. Nowadays the origins of f2 as as the fraction f/2 are largely forgotten but it is because the f number represents a fraction that it works in 'reverse' and the higher the number the smaller the hole. Now here's the curious part ....... to this day, there is no official definition, or even universally accepted definition, of the f in f Stop.. My source, the expert, Bill, put forward that it derives from formulated stop because it was derived from a formula. I never heard this anywhere else. If you Google you will find all sorts of possibilities put forward, of which the more plausible range from focal stop (common) through factorial stop, fractional stop, and at the sillier end of the spectrum finestra stop (because the word 'finestra' is Italian for window). As with any Google search discretion is needed. In general it would seem that Jon Hodges' original 'fractional number' combined with Waterhouse's 'stop' are regarded as the most probable and plausible source. Nowadays many modern lenses, especially cine lenses, no longer use f stops as the formula becomes less and less valid with today's complex compound lenses using special high refraction glasses. We now have instruments capable of measuring the absolute real transmission of a lens on a test bench and these are used on high end modern lenses to provide transmission stops or T stops. For the sake of consistency with other lenses and exposure meters T stops still use the same scale and numbers as f stops even though they no longer have real relevance to measured transmission. So now you know ......... sort of ........ _________________ The subtlety and conviction of any Photoshop effect is invariably inversely proportional to the number of knobs on it ....... |