A very nicely written and presented set of articles. Even for those such as myself who will primarily stick with digital, there is much to learn here in regards to the fundamentals of properly exposing images.
Burghclerbilly
February 3, 2019 10:51 am
8K monitors, 12,800dpi scans, 100mp sensors; still nothing beats a Velvia slide on a lightbox.
i remember, many years ago when I was just getting seriously interested in photography, attending a presentation by the renowned and pioneering wildlife photographer Stephen Dalton at my local camera club. He was using 6×7 format Ektachrome transparency film to photograph insects in flight using a multiple high speed flash setup of his own design at a time when achieving a sufficiently high power output combined with the necessary ultra short duration needed to freeze an insect’s beating wings was considered impossible. After the talk, he laid out a number of transparencies on a large lightbox for the audience to see. I took one look and was utterly gobsmacked. I don’t stun easily but the colour, the detail, the sharpness and the sheer beauty of his images stopped me in my tracks. It was a moment which changed my photographic life. Some people are simply inspirational.
You probably know Ghislain Simard’s work then – simphoto.com. D3x is closest to slide quality in my mind.
JohnD
February 3, 2019 10:29 am
I hiked the Hoh rainforest years ago and camped next to a tree that was 150 feet tall if it was an inch. Rain never touched the ground. It’s a beautiful and sacred place. Always a joy to read an article about photography employing the medium of film, which is my choice. Thank you for a fascinating series.
Walt
January 1, 2016 8:42 am
from the chart at the top, 1.48 inches (450mm) – actually, 450mm is about 1.48 FEET or 17.7 INCHES
Hello Walt, Thanks for catching that! I fixed the “apostrophe typo”. – Rick
Bengt Nyman
January 1, 2016 3:46 am
Hi, Thank you for trying to offer a simple explanation. However, with he inverse square law being known by most, the subject needs to be complemented by the lens formula. Especially when adding extension tubes, altering the camera flange distance and thereby the image distance. A couple of optically correct figures saves on text and puts the subject into focus.
Hello Bengt, Thanks for your comment! Indeed, the thins lens equation is the mathematical basis for all of the optics. For brevity, I placed the lens diagrams and this equation on the page for the mathematical derivations. – Rick
Hi Rick, I find your article especially interesting because optical physics is one of my pet subjects, and as you’ve mentioned, there are many textbooks (and I’ll add: many on-line articles) that contain inadequate and/or erroneous explanations and fundamental technical errors.
In the context of macro photography, your explanation that it is the inverse-square law that causes the light loss, is both succinct and more than sufficiently adequate. The camera lens is indeed projecting an image of the scene onto the image plane (the film/sensor). Placing a lens away from the image plane at twice its focal length (to obtain a 1:1 reproduction ratio; a magnification ratio of 1) will result in a light loss of precisely 2 EV in the central area of the image plane.
Knowing the effective f-stop *is* actually important. Setting the aperture control ring of a macro lens to, say, f/16, and its focus distance for 1:1 reproduction ratio, will result in an effective f-stop of f/32 in terms of: exposure; diffraction; and depth of field [depending on whether or not our chosen DoF calculator has properly taken this into account — likely not, unless it is one which requires us to input the pupil magnification ratio of the lens].
Of course, in many practical situations out in the field, rather than in a studio, the loss of incident light falling on the subject caused by some of it being blocked by the camera and the photographer, will further increase the exposure time needed to capture the image. Commentator Tonio Loewald mentioned this important issue, but it is an entirely separate issue from the main subject of Rick Keller’s in-depth article.
Many thanks, Rick, for your excellent article and for sharing yet more of your wonderful film photography with us. Very best wishes and Happy New Year, Pete
Hello Pete! Thanks so much for your insight commentary and feedback! I always appreciate your point of view and wisdom. I’m happy you found the content interesting and enjoyed the photos. Indeed, this is not an easy topic to write about and explain to either beginners or even advanced photographers in plain and uncomplicated terms, but I tried my best to present the basic principles and illustrate with novel examples based on my own interpretation and experience. I wish I could have covered DOF in depth (pardon the pun), but that one would need a whole article to do it justice. ;-) Happy New Year, my friend! – Rick
Tonio Loewald
December 31, 2015 2:18 am
Actually upon further reflection you’re gaining from inverse square law by getting closer and losing it by magnification. So it’s a wash. The effect you’re seeing is probably caused by the photographer and camera blocking ambient light and angle of incidence.
Tonio, Again, that is an incorrect analysis. Please, re-read the article, re-examine my empiric results, the mathematical derivations, or read one of the references. It is not a wash. Exposure loss due to magnification reigns supreme and trumps exposure gain due to close focusing. – Rick
Tonio, “gaining from inverse square law by getting closer” applies only to point source objects: it applies in astronomy, but it does not apply to general purpose macro-scale photography. E.g. a sheet of white paper, snow, and a brick wall do not get brighter as we walk towards them. The snow on distant mountains is as bright in the image as is the snow on a bird table a few inches away from the camera [ignoring atmospheric attenuation and variations in cloud cover].
Tonio Loewald
December 31, 2015 2:12 am
A bunch of the complexity of your explanation is superfluous. A camera could just as easily focus by adjusting the curvature of its lens (this is how your eye focuses) so the only really important aspect of the analysis is the solid angle from which light is acquired to illuminate the sensor or film. This obeys the inverse square law. That’s it — whether you magnify with optics or by moving closer to the subject.
Hello Tonio, Thanks for your comment! I am afraid that is an incorrect analysis. Please, read the article again, or read one of the references. – Rick
Andrew V.
November 18, 2015 9:05 am
Rick, excellent article and excellent images. I really enjoy the sunset image. I love the way velvia looks when shot properly. I feel like it is an easy film to mess up though.
I’m glad that you are taking the time to share with us your film experiences. It seems difficult to me to find good modern information on the format. I know some people thing that film is dead and should be forgotten about, and that’s ok. I personally love shooting film, It’s also teaching me a lot about my skill as a photographer. Every aspect seems more important even more so when using different formats than standard 35mm digital.
Thanks so much for your comment and feedback! I’m glad you enjoyed the article and the photographs.
Indeed, Velvia can be a technically challenging film to use, especially under difficult lighting; it is not for the faint-hearted. Yet, in the hands of a skilled photographer and artist who is in command and control of his/her vision, light, and technique, Velvia delivers the goods. :)
Yes, you’re right. It is difficult to find modern writings on film photography in the year 2015. The good news is that it is not absolutely necessary to find modern literature on film photography. My advice: pick up any photography book that was authored in the 1940s, ’50s, and ’60s and you just may learn more about general photography than many modern day authors will ever teach you. Trust me on that one.
Well, film photography is not for everyone. In the end, the photographer has to go with what suits his/her style and vision. My advice: ignore the misconceptions that naysayers enjoy perpetuating about film and just follow your heart. You will be a happier photographer in the end. :)
Cheers!
– Rick
Lukasz
November 17, 2015 3:49 pm
Exposure is kinetics. In film, the reciprocity failure at long exposures is due to decline in quantum yield of the silver ions reduction process. These ions are reduced by electrons kicked off by light from chlorides (in a silver chloride crystals), but since this process is reversible, if you give enough time these electrons may actually go back to where they were excitd from. Hence you need to expose longer to give the process higher chance to occur. For shorter exposure times at which reduction process is faster than recombination process the reciprocity rule works. However, if the exposure times are extremely short the reciprocity rule will fail again becuase the light interaction with chlorides will be too short to excite electrons capable of reducing silver ions. In digital, situation is more complex and very much related to noise discussion…
Oh yes, and the fact that exposure of color film is more difficult is because different colors/ lights have different energies and hence we have different quantum yields or kinetics to account for. In general this whole reciprocity rule is nothing else but energy conservation rule and with filters you slice energy portions that reach the film. Sorry for geeky comments but some may be interested ;)
A very nicely written and presented set of articles. Even for those such as myself who will primarily stick with digital, there is much to learn here in regards to the fundamentals of properly exposing images.
8K monitors, 12,800dpi scans, 100mp sensors; still nothing beats a Velvia slide on a lightbox.
i remember, many years ago when I was just getting seriously interested in photography, attending a presentation by the renowned and pioneering wildlife photographer Stephen Dalton at my local camera club. He was using 6×7 format Ektachrome transparency film to photograph insects in flight using a multiple high speed flash setup of his own design at a time when achieving a sufficiently high power output combined with the necessary ultra short duration needed to freeze an insect’s beating wings was considered impossible. After the talk, he laid out a number of transparencies on a large lightbox for the audience to see. I took one look and was utterly gobsmacked. I don’t stun easily but the colour, the detail, the sharpness and the sheer beauty of his images stopped me in my tracks. It was a moment which changed my photographic life. Some people are simply inspirational.
You probably know Ghislain Simard’s work then – simphoto.com. D3x is closest to slide quality in my mind.
I hiked the Hoh rainforest years ago and camped next to a tree that was 150 feet tall if it was an inch. Rain never touched the ground. It’s a beautiful and sacred place. Always a joy to read an article about photography employing the medium of film, which is my choice.
Thank you for a fascinating series.
from the chart at the top, 1.48 inches (450mm) – actually, 450mm is about 1.48 FEET or 17.7 INCHES
Hello Walt,
Thanks for catching that! I fixed the “apostrophe typo”.
– Rick
Hi,
Thank you for trying to offer a simple explanation.
However, with he inverse square law being known by most, the subject needs to be complemented by the lens formula.
Especially when adding extension tubes, altering the camera flange distance and thereby the image distance.
A couple of optically correct figures saves on text and puts the subject into focus.
Hello Bengt,
Thanks for your comment! Indeed, the thins lens equation is the mathematical basis for all of the optics. For brevity, I placed the lens diagrams and this equation on the page for the mathematical derivations.
– Rick
Ok. That’s more like it.
Hi Rick, I find your article especially interesting because optical physics is one of my pet subjects, and as you’ve mentioned, there are many textbooks (and I’ll add: many on-line articles) that contain inadequate and/or erroneous explanations and fundamental technical errors.
In the context of macro photography, your explanation that it is the inverse-square law that causes the light loss, is both succinct and more than sufficiently adequate. The camera lens is indeed projecting an image of the scene onto the image plane (the film/sensor). Placing a lens away from the image plane at twice its focal length (to obtain a 1:1 reproduction ratio; a magnification ratio of 1) will result in a light loss of precisely 2 EV in the central area of the image plane.
Knowing the effective f-stop *is* actually important. Setting the aperture control ring of a macro lens to, say, f/16, and its focus distance for 1:1 reproduction ratio, will result in an effective f-stop of f/32 in terms of: exposure; diffraction; and depth of field [depending on whether or not our chosen DoF calculator has properly taken this into account — likely not, unless it is one which requires us to input the pupil magnification ratio of the lens].
Of course, in many practical situations out in the field, rather than in a studio, the loss of incident light falling on the subject caused by some of it being blocked by the camera and the photographer, will further increase the exposure time needed to capture the image. Commentator Tonio Loewald mentioned this important issue, but it is an entirely separate issue from the main subject of Rick Keller’s in-depth article.
Many thanks, Rick, for your excellent article and for sharing yet more of your wonderful film photography with us. Very best wishes and Happy New Year,
Pete
Hello Pete!
Thanks so much for your insight commentary and feedback! I always appreciate your point of view and wisdom.
I’m happy you found the content interesting and enjoyed the photos. Indeed, this is not an easy topic to write about and explain to either beginners or even advanced photographers in plain and uncomplicated terms, but I tried my best to present the basic principles and illustrate with novel examples based on my own interpretation and experience.
I wish I could have covered DOF in depth (pardon the pun), but that one would need a whole article to do it justice. ;-)
Happy New Year, my friend!
– Rick
Actually upon further reflection you’re gaining from inverse square law by getting closer and losing it by magnification. So it’s a wash. The effect you’re seeing is probably caused by the photographer and camera blocking ambient light and angle of incidence.
Tonio,
Again, that is an incorrect analysis. Please, re-read the article, re-examine my empiric results, the mathematical derivations, or read one of the references. It is not a wash. Exposure loss due to magnification reigns supreme and trumps exposure gain due to close focusing.
– Rick
Tonio, “gaining from inverse square law by getting closer” applies only to point source objects: it applies in astronomy, but it does not apply to general purpose macro-scale photography. E.g. a sheet of white paper, snow, and a brick wall do not get brighter as we walk towards them. The snow on distant mountains is as bright in the image as is the snow on a bird table a few inches away from the camera [ignoring atmospheric attenuation and variations in cloud cover].
A bunch of the complexity of your explanation is superfluous. A camera could just as easily focus by adjusting the curvature of its lens (this is how your eye focuses) so the only really important aspect of the analysis is the solid angle from which light is acquired to illuminate the sensor or film. This obeys the inverse square law. That’s it — whether you magnify with optics or by moving closer to the subject.
Hello Tonio,
Thanks for your comment! I am afraid that is an incorrect analysis. Please, read the article again, or read one of the references.
– Rick
Rick, excellent article and excellent images. I really enjoy the sunset image. I love the way velvia looks when shot properly. I feel like it is an easy film to mess up though.
I’m glad that you are taking the time to share with us your film experiences. It seems difficult to me to find good modern information on the format. I know some people thing that film is dead and should be forgotten about, and that’s ok. I personally love shooting film, It’s also teaching me a lot about my skill as a photographer. Every aspect seems more important even more so when using different formats than standard 35mm digital.
Keep up the good work and the good writing.
Hello Andrew!
Thanks so much for your comment and feedback! I’m glad you enjoyed the article and the photographs.
Indeed, Velvia can be a technically challenging film to use, especially under difficult lighting; it is not for the faint-hearted. Yet, in the hands of a skilled photographer and artist who is in command and control of his/her vision, light, and technique, Velvia delivers the goods. :)
Yes, you’re right. It is difficult to find modern writings on film photography in the year 2015. The good news is that it is not absolutely necessary to find modern literature on film photography. My advice: pick up any photography book that was authored in the 1940s, ’50s, and ’60s and you just may learn more about general photography than many modern day authors will ever teach you. Trust me on that one.
Well, film photography is not for everyone. In the end, the photographer has to go with what suits his/her style and vision. My advice: ignore the misconceptions that naysayers enjoy perpetuating about film and just follow your heart. You will be a happier photographer in the end. :)
Cheers!
– Rick
Exposure is kinetics. In film, the reciprocity failure at long exposures is due to decline in quantum yield of the silver ions reduction process. These ions are reduced by electrons kicked off by light from chlorides (in a silver chloride crystals), but since this process is reversible, if you give enough time these electrons may actually go back to where they were excitd from. Hence you need to expose longer to give the process higher chance to occur. For shorter exposure times at which reduction process is faster than recombination process the reciprocity rule works. However, if the exposure times are extremely short the reciprocity rule will fail again becuase the light interaction with chlorides will be too short to excite electrons capable of reducing silver ions. In digital, situation is more complex and very much related to noise discussion…
Oh yes, and the fact that exposure of color film is more difficult is because different colors/ lights have different energies and hence we have different quantum yields or kinetics to account for. In general this whole reciprocity rule is nothing else but energy conservation rule and with filters you slice energy portions that reach the film. Sorry for geeky comments but some may be interested ;)
Thanks for your comments, Lukasz! Indeed, reciprocity departure is a very interesting phenomenon.
Cheers!
– Rick