[Charlotte]

Moved the following discussion to its own thread, i.e. here!

Originally Posted by Les Meehan

Ah, snow...
Now why does snow, or any predominantly light toned scene/subject, cause people so much trouble? The simple reason is that too many people don't bother to understand exposure control.

The first thing to do is test the contrast range of your camera. Most people recommend treating a DSLR as you would transparency film (that's fine if you know about transparency film but now many people have never used film) which is good advice. To test the contrast range of your camera make a series of exposures of a neutral (not coloured) textured surface in even light (an overcast day and a grey towel are a good combination, avoid brightly coloured things for this as your light meter is colour sensitive). Make the first exposure at the camera suggested exposure. Close down one stop (reduce exposure by one stop) and make the second exposure. Make four more exposures each time reducing the exposure by one stop. If your camera does not allow manual control use the ISO to obtain the changes (alternatively chuck it away and buy a proper camera). This sequence should produce a series of progressively darker images of the towel going into pure black.

Next, return to the camera suggested exposure and make a second series of exposures but this time increasing the exposure (making the towel lighter each time) by one stop for each shot. Make about five exposures, this sequence will take the towel lighter until it goes into pure white.

Put the images into your editing software WITHOUT ANY MESSING ABOUT! If shooting in RAW, don't do anything during the conversion as you want basic info. You want to see the 'pure' images. Zoom each to 100% and carefully examine the TEXTURE of the towel (or whatever textured subject you used). Due to uneveness of lighting/camera things just examine the centre portion of the images for consistency.

Find the darkest image that just shows the minimum texture. This is your lower limit of exposure for detail.

Examine the lighter images and again find the one that just retains a little detail. This is your upper limit for detail.

At the end of this simple test you will KNOW exactly how dark a subject can be allowed to go before it loses all detail and goes completely black. Also, you will know how light a subject can go before it tunrs completely white.

OK, lets say your result show that the last detail in the dark images is the image that received three stops LESS exposure than the camera recommended. Also, the lightest image to retain minimal detail was the one that received two stops more exposure. You can safely say that the camera has a texture range of 5 stops (which is pretty usual for a DSLR), this is the difference in stops not the number of stops of exposure which would be 6.

So, you now have enough info to accurately expose any subject or scene by asking yourself two question: How dark or light do I want this subject and how much detail do I want to have in it? When I say 'subject' I am refering to a selected area of a scene from which you take a meter reading e.g. a shadow or a light area.

Now back to the snow problem. Move close enough to an area of the snow scene where the snow is in sunlight (or the brightest light, not in the shadows). Fill the viewfinder with an area of snow and take a meter reading. If you expose at this reading you will under-expose the snow to a mid-grey tone. Now ask the two questions. The answer may be: I want this snow as light as possible but with a hint of texture. No problem. Increase the indicated exposure by the same number of stops as your test told you for the last detail in a light tone (in our example that would be two full stops). Take the shot and be amazed how easy it was to get perfect snow!

If you wanted to check how dark the shadows would be and whether they will retain detail simply move in and meter a shadow area. If the shadow has a meter reading that is 5 stops or LESS different from the meter reading you have set for your snow the shadow will retain detail and not be black. Any dark area that is more than 5 stops different will be pure black in the image. Conversely, any area of the scene that has an exposure higher than the snow area will be pure white in the image.

Of course, this procedure works for every picture you make and is the basis of the Ansel Adams zone system. Now there's food for thought. Happy experimenting.

Originally Posted by Charlotte

Ah, so you did prepare a tutorial to adapt the Zone System for DSLR, Les Excellent stuff, thanks for such a clear + concise explanation, I shall certainly be giving that test a go - save an awful lot of time + faffing around at each shoot

I think the tutorial you have set out here also belongs in the Articles + Tutorials section

BTW It's not that ppl "don't bother" to understand exposure control, it's just tricky to get to grips with in the beginning, when there are so many settings to co-ordinate in the 'simple' task of taking a photo I know this all comes naturally without having to consciously make all those decisions once one has progressed well past 'novice', but until then exposure remains largely trial + error for many amateurs However, your clear explanation here should expedite that learning process for us, thank you!

Originally Posted by Les Meehan

Sorry it got rather lengthy, it wasn't intended as a 'tutorial' but a response to the problem. However, as is often the case, the explanation is harder than actually doing the test which should only take about half an hour at most.

I stand by my 'don't bother' statement which is based on many, many years experience of helping people. As you rightly state, in the beginning exposure control can seem rather tricksy which is why most people don't bother to move up the learning curve and simply waste time guessing and hoping (not a recipe for excellent photography). Even many pro's don't understand exposure control. Hey, there are only two controls to mess with how hard can it be? (only kidding OK!). No, the real problem is the conceptual aspect of exposure control, learning what the shutter speed and aperture relationship is about is easy. The real stuff is taking it into the realms of understanding, measuring brightness values, visualisation, and interpretation. That's where the zone system (or whatever people want to call the method) is the perfect tool, even in this digital age!

Once a person really understands about exposure control they seem to gain a real feeling of being in command of the medium, something many many people never feel. Whenever I have given talks to clubs/groups on the subject of exposure control I always start with the following question:

"How many people in this group can HONESTLY say they can get the desired exposure for every shot they make?"

Inevitably, there is rarely even one person that can hold their hand up and say "Yes, I can.", that isn't me trying to be smart, its true.

I suppose this issue has occupied more than a healthy portion of my photo life, trying to promote an understanding of exposure control (of course, it was the subject of my first book "Creative Exposure Control" which was very well received) and here I am continuing to promote it. Tell me to shut up, please

NO, DON'T SHUT UP!! The total control over exposure you're talking about is exactly what I want!!

I want to be able to get an image out of my camera exactly as I visualise it, no more, no less, i.e. I want IN with control + OUT with trial + error Sometimes I can do it, but not often enough.

BTW I am self-taught in photography, i.e. books, mag's + internet are my resources, no teacher/tutor ... a.k.a. the hard way It is slow going this route, i.e. separating the seed from the hull. I have a lot of the theory straight in my head, but lack the application, i.e. putting it all into practice.

The problem I'm facing at the moment is information overload as against practical experience, i.e. where do I begin! I have lots of ideas I want to try, but not sure how to go about it, so I keep putting off trying. Anyway, I'm rabbiting now, so am telling myself to shut up ... in a second ...............

Point is: discussing rather than just reading is far more helpful, so let's talk about taking control of exposure!

[Les Meehan]

Most of the threads, if not all, usually start with a question but this one seems to have originated sort of half way into the subject because I was responding to the other thread about snow.

I think that to make this new thread more relevant to the title you have given it we may need to take a few steps back. The question is where do we start with this topic? Since I don't really know what you know about the subject of exposure I'm not sure how to proceed. Although we have had a few discussions outside of this forum (prior to you inviting me to visit here), we haven't really established a level of knowledge between us.

What say you and others? Shall we begin with some questions to kick off the discussion?

[Charlotte]

Les - The start of this thread is a bit messy: I started it off by quoting your original post from the snow thread because it contains information which I feel is pertinent to share with all members. I also felt the next couple of posts were pertinent to getting a discussion underway. Unfortunately, this makes for a lengthy beginning.

Here's what I suggest :

1. You copy + paste your 1st post, just the procedure + excluding the bits that are specific to the previous thread, into a new thread in the Tutorials + Guides forum here.

2. You place a link at the end of the tutorial linking to this thread for those who wish to discuss the topic + ask questions.

I think your knowledge + experience will benefit members greatly; the tutorial will get ppl started (on taking control of exposure) and then questions can follow in a thread that is separate from the tutorial (to keep that one uncluttered) for members to progress from the initial test set out by you.

A note about discussions on the forums: It is best to keep posts short, as it can get a bit much reading through reams on screen

So, if you agree with my suggestions above, I look forward to seeing your tutorial in place and I am sure when others see it, there will be some questions or comments posted here fairly soon!

As to the extent of my knowledge, either it will come out in the forum in bite sized pieces, or I'll email you separately. In the meantime, I want to try out your test, + will ask/comment thereafter

[Steve]

Hi guys, I see you are both on to something good here but are a bit lost comining into it from half conversations elsewhere on the forum. If you want to you could just start one thread (probably in the 'Tutorials and Guides' section would be best) and then once you have that started I will clean up the other threads for you. That way all the advice and questions will be in one place and it should be easier for you and everyone else to follow and learn from your input.

I am not telling you to do it this way, its just a suggestion and an offer to help clean up and bring all the information together in one place

[Les Meehan]

I think Charlotte's idea is a good one and I have no problem writing a tutorial on this subject. The only problem I have is that on the Articles and Tutorials front page it states that the articles and tutorials cannot be reproduced without permission as they are the copyright of Pixalo. Although I understand that this is to protect the writing of the Pixalo crew, I will not give away copyright on any of my writing whether it is for this forum or another purpose.

I know the spirit of a forum is the free interchange of info and I don't mind that but this clause would prevent me from using the tutorial in other context which isn't acceptable to a working pro.

Of course, I will do the tutorial as long as it is clear I retain copyright to the material, with a copyright statement at the start of the piece, if that is acceptable.

Also, I think Steve's idea is also sound, to clean up this thread.

[Steve]

Originally Posted by Les Meehan

I think Charlotte's idea is a good one and I have no problem writing a tutorial on this subject. The only problem I have is that on the Articles and Tutorials front page it states that the articles and tutorials cannot be reproduced without permission as they are the copyright of Pixalo. Although I understand that this is to protect the writing of the Pixalo crew, I will not give away copyright on any of my writing whether it is for this forum or another purpose.

I know the spirit of a forum is the free interchange of info and I don't mind that but this clause would prevent me from using the tutorial in other context which isn't acceptable to a working pro.

Of course, I will do the tutorial as long as it is clear I retain copyright to the material, with a copyright statement at the start of the piece, if that is acceptable.

Also, I think Steve's idea is also sound, to clean up this thread.

Les…the copyright statement is to protect us and your work only, you are not assigning us rights to your work other than the ability to display it here for as long as we see fit (with full credit to you as the writer). This was introduced to stop theft and also to protect the sites content.

Several members here have written and submitted articles for publication, Gary Bagshawe, Rob Barron, Silkstone etc and in every case we make it very clear that the article is their work and further reproduction, copying or display elsewhere has to be with their permission. We don’t control copyright nor claim exclusive rights.

If you are happy with that Les, then please go ahead and create the article or tutorial and we will gladly consider it for publication along with our other articles and tutorials

I hope that puts your mind at rest and please shout if you have any more questions

[Les Meehan]

Thanx Steve for clearing that up, I rather thought it would be thus but as a seasoned pro I know one has to get this sort of thing sorted 'before' doing anything.

I will gladly submit a piece on exposure control for consideration.

[Rob Barron]

Les, I am looking forward to reading your work. Could you also please tell me about the book including ISBN as I would love to read it.

thanks,
Rob

[Les Meehan]

Hi Rob

Nice to meet you! If you search in amazon/books using my name my published titles will be listed. The 'Creative Exposure Control' book (ISBN-13: 978-0817437275) was my first so don't be put off by the year.

You may also want to check out my website at index if you want to delve deeper into a few things (I know from reading your stuff here that this is probably academic for someone with your experience).

Regards
Les

[Les Meehan]

OK, I.ve posted a bit of an article on exposure control in the tutorials section and support images in my gallery. Let the thread commence!

Creative Exposure Control