Digital Exposure Latitude

http://www.dpreview.com/reviews/nikonD60/page18.asp

http://www.dpreview.com/reviews/nikonD60/page19.asp

Yes, EV number is equivalent to f-stops.

EV is an absolute value, whereas f stops are relative. There can be any number of aperture and shutter speed combinations that yield the same EV. The EV of a sunny day is 15. But f16, 1/100 and ISO 100 properly exposes for EV 15 as does f8, 1/400 at ISO 100.

From my experience, a DSLR will have about 6 stops of dynamic range. Some will claim more. And by shooting raw, it is possible to pull back some over exposed highlights and possibly get a bit more DR. I've heard that the DR of a DSLR is about the same as shooting slide film, but I have found that even slide film (Sensia 100,which I used to shoot a lot of) has better shadow detail and the highlights hang in there better than with my DSLR. I use a Canon 10D, but I don't think DR range has improved all that much, but then again, I have not campared the 10D to newer cameras.

The dpreview links from Rob should give you an objective, numerical answer. I strongly urge you, however, to do your own tests...not because dpreview or any other source is suspect, but because dynamic range seems to mean different things to different people. Some people will be quite happy with shadow detail that can only be extracted with significant adjustments to the raw file and that has lots of noise. Others want to see noise free shots in jpeg. Etc., etc.

The important question is how much dynamic range can you capture that will satisfy your needs. To answer that, you need to take a number of shots of high contrast scenes, e.g., white walls in bright sunlight adjacent to shadowed areas. Use the meter on the camera to separately measure the highlights and shadows and see how the photos come out when you try to include both in the same shot.

In general, cameras like your D60 should give you more dynamic range than slide film and less than negative film. Compact (i.e., point and shoot) digital cameras will have less dynamic range than the D60, while the most recent, top-of-the-line DSLRs will have more dynamic range than the D60.

I guess I was typing at the same time as Phil--I didn't intend my post to sound like I was trying to directly contradict his opinion on the relative dynamic range of slide film and digital. I stand by my statement, but I think the difference with Phil may simply illustrate that different people see things differently. Phil prefers the handling of shadows in a particular slide film to his 10D, so there would not be much sense in trying to do a numerical comparison because it likely wouldn't change his artistic preference. FWIW, the dxomark.com website allows easy comparisons of the dynamic ranges of various cameras. They show a 10D as having about one and a half stops less dynamic range than a recent DSLR like a D90; a D60 falls in between.

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Thank you each and every one. That is a great help, my Nikon manual assumes that I know all this and it is simply refreshing my memory on some points. I made the move from film to digital about six months ago and it's been a steep learning curve for an old guy.

try the following rough and ready guide. film negative and and raw digital have about the same dr which is 8-9 stops. jpeg digital has about 6 stops of dr. slide film has about 4+ stops of dr. if you are talking headroom then film nagative and raw has about 2 stops, while jpeg has about 1 stop. and film slides has zero headroom.

note i shot film slides for over 3 decades, that was kodak ecktachrome 64, which has the 4+ stops of dr and zerio headroom and had no trouble getting pics of any scene i wished to shoot. the limitations on dr and headroom was simply something you got used to and made changes in the technique used. having zero headroom with the ecktachrome 64 simply made sure that you shot carefdully with a full analysis of the exposure before the shot. also with slides if you overexpose there is absolutely no recovery of any highlights.

If you do HDR (High Dynamic Range) processing of digital images in programs such as Photoshop, your dynamic range is greater than that of film. You do the old 1 stop over and under bracketing of the image and Photoshop will merge all 3 images together to get one image with a dynamic range that gets the details of the shadows and the highlights that the bracketed shots captured. HDR is actually much more flexible than that but most DSLRs today have automatic 3 shot bracketing so that is easy to do. If you have the time, you can do much more elaborate bracketing and the only limit on what you can merge is the memory on your computer and your processor speed.

Danny

My 5D, always in raw, has noticeable more dynamic range than shooting Velvia or any of the other slide films (mainly Provia ) that I've used a lot of. I need grads much less frequently, and of course the fact that you can view a histogram is probably "worth" an extra stop or so of dynamic range anyway since you can make sure to use all the available range in a contrasty exposure; which is difficult with slide film unless you are taking multiple readings witha trusted spotmeter. Even the 10D I had for a little while had better DR than Velvia.

Dynamic range varies from camera to camera and sensor to sensor. They all have more DR than slide film - sort of. Slide film handles overblown highlights more gracefully than a digital sensor, so you might have to under-expose a digital cimage a bit in the same shooting circumstances in order to avoid ugly effects. This could bring out more noise in the darker regions of the image.

No matter how you capture your images, care must always be taken to play to the strengths and avoid the weaknesses of each technology.

Yeah I'm gonna suggest doing your own little DR test, there's a few around, but esentially what you need to establish is how far into the highlights you can push before you clip them.

Unlike film digital is a linear rendering, which is why raw files and poorly converted jpg's/TIFF's are less pleasant to look at then one would like. I mention that because the curve you apply to your file can effect the DR as well.

Latitude varies a lot but in general a well handled raw will have a little more latitude then slide film, where the issue arises is how you display all the information in the file, digital commonly clips different channels in the highlights at different points and you always have to set an appropriate black point because otherwise noise will be noticeable in the shadows.

I'm not a Nikon shooter myself but I know on camera's as old as 20D's you get 7 stops to play with, and on newer nikons and canons you get 8-9 stops of usable range (note this number can change somewhat depending on the iso used).

establish how many stops above middle grey your camera can capture before chanel clipping occurs (which will also depend on the temporature of the light) and expose for that, while being aware of how much range you have in the shadows before noise interferes with detail.

"Yeah I'm gonna suggest doing your own little DR test, there's a few around, but esentially what you need to establish is how far into the highlights you can push before you clip them."

This is totally unnecessary with digital. Take a photo and look at the histogram the camera gives you. You can see if you are clipping and you can immediately take a second shot with a different exposure if the histogram shows clipping.

If the DR of the scene is wide enough that you cannot get a good exposure without some clipping, bracket until you get all the shadow and highlight details. Then run the different exposures through Photoshop's HDR processing and you can get an image that has far more DR than any film can record. Any DSLR should have automatic 3 shot bracketing as a standard feature. The whole problem of limited DR is much less of a problem with digital because of HDR.

Danny

[[This is totally unnecessary with digital. Take a photo and look at the
histogram the camera gives you. You can see if you are clipping and you can
immediately take a second shot with a different exposure if the histogram shows
clipping.]]

I disagree. The histogram is not as simple as that.

A lot of cameras will show you a histogram based on in-camera JPG settings (the preview JPG saved within the RAW file). This can result in you thinking you've clipped highlights when you haven't.

It's always best to set your saturation and contrast values in-camera to low, even if you're not shooting JPGs. This will allow the histogram to better represent what you'll get out of the RAW file.

On the flip side, if your camera doesn't show you a 3-color histogram, you are likely not going to see when one color channel blows out. A single histogram may look fine but the red channel (for example) may already be blown.

"The histogram is not as simple as that."

Accurately knowing the real DR of your camera is nice but trying to figure out the right exposure to get all that DR or figuring out if the DR of the scene exceeds the DR of your camera requires using the histogram. The histogram is fast, easy and simple. As long as it is reasonably close to the real DR of the camera, that is all you need. For digital all you really need to know is whether the exposure has no clipping or if you need to bracket and do HDR processing to handle clipping. False clipping information is okay. All that means is you do a second set of bracketed shots that you did not need to. But digital images are free and as the larger memory cards can store around 400 shots, you need not worry about costs or running out of memory.

When you are shooting a sunset or sunrise where the light and DR is rapidly changing, you need some method of checking the exposure of the image that is fast, simple and easy. The histogram meets the KISS principle. Otherwise by the time you figure out that you need to re-shoot with a different exposure, the light has changed.

The histogram provides instant feedback as to whether the exposure is good or bad. There is no need to wait until you download the images to a computer to find out you blew the exposure on every shot. It is far superior to anything else unless you are shooting tethered to a program that can accurately determine the exposure. Even with a small laptop, that is hard to do on the go. A camera that does not provide a reasonably good histogram is a camera you should get rid of. Even a master craftsman cannot do a good job with bad tools.

Danny

[[The histogram is fast, easy and simple]]

The histogram can give you good information, if you know what it is telling you. I fail to see a problem with encouraging people to better understand what their histogram is ACTUALLY saying so there are no surprises. The histogram is better than any other on-camere tool currently available but it still has its limitations.

[[A camera that does not provide a reasonably good histogram is a camera you should get rid of]]

The histogram can and will lie to you in challenging, non-bracketable, situations.

A master craftsman would explore the full range of his tools and not accept anything as given.

"A master craftsman would explore the full range of his tools and not accept anything as given."

For all its limitations, the histogram is fast, simple, easy and always there for you to use. Knowing the limitations of the histogram for your particular camera is certainly good advice but your posting implies that there are other tools that are better.

So what other tools do you recommend? How do they compare with the histogram for speed, simplicity and convenience? Back in the days of film, I used to use a spot meter and set the exposure based on it and tests of the actual DR of the film I was using. It was a lot of work and slow. It was really only suited to photographing mountains that did not move. For sunset and sunrise photos or anything that moved, it was not a useful tool.

Danny

I agree with Rob.
Most of the time people just dont know that the histrogram is showing a pesimistical interpretetion on the real RAW capture since it reflects the JPEG conversion and not the real RAW. many potential good captures are avoided because of a wrong histogram reading.
Some pictures may show clipping on the histogram but the real RAW(12bit or 14bit or 16bit) file covers way more latitude of that interpreted by the 8bit JPEG image conversion you see interpreted by the histogram.
That is why people think that they have magically recovered information from the shadows and highlight when the information was always there to start with.
I high dynamic range Image is one that exceeds the ability of an 8bit image or 8bit monitor to encompass, more than 255:1, what is more than 8 stops.
* low Dynamic range---A 8bit (tiff or JPEG)has a 255:1 Ratio
* low Dynamic range---A12bit (RAW) has a 4,000:1 Ratio
* Borderline DR---------A14bit (RAW) has a 16.000:1 Ratio
* Borderline DR---------A16bit(RAW or TIFF has 48bits RGB so16bit per channel) has a 33.000:1 Ratio
* HDR---------------32 bit floating point (96 bits RGB so 32bit per channel) has an infinite Ratio.
Jim. I hope that answers the question.

The D60 has a DR averaging from 11.6Fstops out of camera12bit NEF and 10.5Fstops out of camera JPEG's
At the upper end of the tonal scale, dynamic range is dictated by the point at which the RGB data "saturates" at values of 255, 255, 255. At the lower end of the tonal scale, dynamic range is determined by the point at which there ceases to be any useful difference between adjacent tonal steps.
Determining the DR out of a camera is subjective , remember there are bigger color spaces different than your cameras aRGB and sRGB.
By the way why you want to know this? what useful implications have to know this info? just asking I'm curious.
Regards.
J.A.R.T.

A camera that does not provide a reasonably good histogram is a camera you should get rid of. Even a master craftsman cannot do a good job with bad tools.
Danny.
I would like to know what camera Danny is using that is giving such accurate histograms, perhaps "RAW HISTOGRAMS?"
I think a MASTER craftsman dont depend on his tools but in the way he can find to circumvent his problems to achieve a master piece.

"I would like to know what camera Danny is using that is giving such accurate histograms, perhaps "RAW HISTOGRAMS?"
I think a MASTER craftsman dont depend on his tools but in the way he can find to circumvent his problems to achieve a master piece."

I would like to know what tool other than a histogram that you recommend. All the criticism of histograms ignores the fact that it is fast, simple, easy and convenient and is certainly accurate enough for use by a beginner . This is the beginner's section after all. For an experienced photographer who has done the work to accurately characterize his camera's DR and the historgram's accuracy, it is also the fastest, simplest, easiest, most convenient and very accurate tool today.

I have used spot meters and the Zone system. It is as good as it got for maximizing DR but it is a slow process and requires some work to use. The histogram is the digital equivalent of the zone system. The big difference is any beginner can use the histogram and get Zone System exposure results immediately. Again, what tool do you recommend that can give the same result so easily?

Danny

I said it had limitations, like any tool, and those limitations should be recognized. I said a photographer should understand what the histogram is actually showing you. If you consider stating facts a "criticism" then there's no point in taking this any further. You obviously are not reading any of the responses here.

"I said it had limitations, like any tool, and those limitations should be recognized. I said a photographer should understand what the histogram is actually showing you. If you consider stating facts a "criticism" then there's no point in taking this any further. You obviously are not reading any of the responses here."

I have acknowledged this point in my postings but since you obviously are not reading clearly my responses here, we can both agree that there is no point in continuing this discussion.

Danny

When histograms only reflected the luminance channel people was still able to take great shots.
My intention is not to criticize the histogram, that would be pointles, I also agree the histogram is a tool that greatly helps in the process of taking a picture but ingonirng the "FACT" that at the moment it stll has big limitations would be wrong on my part, and since this is the begginers forum its also important to let the people know about this limitations so they can further research about the topic if they find it of any interest.
I for my part have posted in different threads about the subject or related ones explaning how to more accurately read the histogram for better results and ways to make it more closely reflect the original file.
The "histogram" is a tool that can be used to achieve good results but also knowing how it behaves depending the "subject matter" you are photographing will make you improve your technic and maximize the oportunities of taking usable images.
I consider that topic should be better discussed as the subject of a different thread since the OP's question has been already answered.
Regards.
J.A.R.T.