Category Archives: Camera

Canon vs Nikon

CanonVsNikonSteven Christenson is a long time Canon user who recently also added a Nikon D600 to his stable of camera bodies. The thought behind adding a Nikon was to get a higher performing body than his Canon 5D Mark II *and* subject himself to Nikonology so that he can be more effective at teaching workshops. Workshop participants tote many brands of cameras, the dominant brands being Canon and Nikon. As an additional side benefit Steven can now tease himself about owning a lesser camera.  🙂

Steven does NOT believe that a Nikon is automatically a lesser camera nor that a Macintosh is a computer substitute – these are things he says just to spark friendly conversation.

Previously Steven – a Canonite, and Eric Harness – a Nikonian have swapped cameras for a spell to encourage cross-education. It seemed time to bite the sensor – so to speak – and not rely on using Eric’s equipment. Steven is using the Nikon D600 with (and without) a Rokinon 24mm f/1.4 manual focus lens for night photography and astrophotography. Steven took both the Nikon D600 and the Canon 5D Mark II on a 3-week tour of Europe which provided plenty of time to form conclusions about the operational differences between the cameras. As a result of his experiences learning and using the Nikon he presents his top issues and keeps score to decide which brand is better from an ease of use point of view.

fEE – An Aggravating Error

Right out of the bag, literally, things went poorly for the new Nikon.  With the new lens mounted backward* on the Nikon body all of Steven’s attempts to take pictures were met with fEE. You may be thinking, yeah, but didn’t you just say he mounted it backward?  Well, no, Since childhood he’s learned that “righty-tighty, and lefty-loosey” define how one tightens and loosens things. But the Nikon is reversed. To attach the lens you rotate it LEFT, not right.  Ok, so if the problem wasn’t the backward rotation of the lens to mount it, what was it? It turns out, that the Rokinon 24mm f/1.4 lens *is* able to have the camera control the aperture BUT you *must* set the lens to f/22 or the fEE error results. It’s not optional. This seems ludicrous. When he puts a manual focus / manually controlled aperture lens on a Canon it all works just fine, that is, in the Canon metering works just fine.  Why Nikon insists on messing with the aperture on a manual lens is troublesome. This behavior sabotages one trick that time-lapse photographers use to prevent the camera from random fluctuations of the iris (and coincidentally needless mechanical wear). Left to the camera slight changes in the aperture result in visible flicker. Timelapsers, therefore, use the “depth of field” preview button and then slightly twist the lens to disconnect the electrical contacts thus preventing the camera from monkeying with the aperture. Since the Nikon control of the lens is mechanical, not electrical, it’s not clear if there is a clean way to keep the Nikon from messing with the manual aperture control on the lens. We are adding a point to Canon’s score for more sensible behavior.

Score : Canon 1, Nikon 0

Can’t Focus

OutOfFocusThere was another problem, too. After mounting the Rokinon on the Nikon, it was impossible to focus at infinity.  Checking the diopter controls, the security of the lens mount, etc. resulted in no joy. Since both lens and camera were a gift, Steven worried that he’d have to tell his wife that something was broken. Indeed, something is “broken” but exactly what is not clear BECAUSE when he turned ON the Nikon, it suddenly became possible to manually focus the lens at infinity.  Remember this is a MANUAL focus lens! Steven regularly sets up his Canon and pre-focuses with the camera turned off. His initial thought was that the Nikon hadn’t pulled the aperture open… but the view didn’t become brighter when the camera was turned on so something else odd is going on. What? Don’t know, and it’s an intermittent issue. Canon gets another point for not having this bizarre behavior.

Score: Canon 2, Nikon 0

Viewfinder = Confusion

The next headbanger came when Steven tried to actually shoot with the camera.  The viewfinder was filled with all the content intended but the shot was far different from the view in the viewfinder. How different? Well there was about 30% more in the view than appeared in the shot.  Unfortunately this unexpected twist meant that Steven’s first night shots of the sky over Santorini were unstitchable due to insufficient overlap. Do you know what the problem is?

Steven couldn’t figure this one out, though weeks later he pleaded with Eric for help and Eric resolved the problem!  Here is a clue: the image size was also much smaller than expected: 3936×2624 pixels rather than 6016×4016.  Apparently the camera either came preset to or was somehow accidentally put into “DX” mode where only the center of the sensor is used. This behavior is readily noticeable when using Live View. In a warped way, I guess this is what allows Nikon users to mount any lens to any Nikon body – cropped or not – and get a result.  Canon’s approach is to not permit mounting of a crop factor lens on a full frame body.  The Nikon center crop mode results in smaller files. If that also achieved faster frame rates a full point advantage would be awarded to Nikon, but that doesn’t seem to be the case. Nikon scores 0.5 points for versatility (though we are sorely tempted to subtract points for unexpected behavior).

Score: Canon 2, Nikon 0.5, Steven -1, Eric +1

Chameleon Lenses

ChameleonSteven intentionally got the Nikon G-Mount Rokinon 24mm f/1.4 for it’s speed and because it’s a form factor that he didn’t already have. But a nice little side benefit came with it. Because of the lens mounting schemes used, it is possible via a cheap little adapter to use pretty much ANY Nikon lens on a Canon body (but NOT vice versa). Nikon gets a full point for this benefit.

Score: Canon 2, Nikon 1.5, Steven -1, Eric 1

Finding Your Way Around

ConfusedObviously the menu systems are different on a Nikon and Canon. Mostly its a matter of taste. Both Canon and Nikon camera models regularly and needlessly re-arrange the names and locations for settings.  There is no clear winner here. Likewise the locations of buttons and the features on those buttons move around as bodies change – sometimes maddeningly so.  Steven doesn’t have enough experience with Nikon to form an opinion about this, but every one of his 3 Canon bodies has buttons “needlessly moved”.  For example the top-deck light button moved from the innermost to the outermost button. Why? Canon must have been bored. Steven does find it annoying that the top deck light on the Nikon D600 is built into the on-off switch… and the light doesn’t stay on long!  In fact, locating the Nikon on-off switch just above the settings wheel has resulted in several unintentional turn-offs of his Nikon.  Accidental power off is happening less over time though.

One example of a difference in philosophy between the Nikon and the Canon is in the ISO setting. On Canons you press the ISO button (top deck), then spin the wheel. You can change the ISO one-handed.  On the Nikon, you must hold a button (lower left) on the back and spin the control with the other hand – two-handed control. I prefer one-handed control it’s easier in the dark. On the other hand, you must wade through several menu settings to format a card in the Canon. A double, double-button press (plus a selection) allows you to format one of the two cards in the Nikon. It’s a little SCARY that I can accidentally format one or both cards by accidentally holding the wrong buttons on the camera.

An example of a Nikon gaff is in image delete. Press delete then press delete again and poof, image shredded.  If Steven fumbles (and he’s known to do that) it means an image can go up in smoke by accident. The Canon method is to press delete then require a scroll and a third operation for confirmation.  It’s a little more tedious, but safer.  It is clear, however that the Nikon has more buttons and more controls available with less total fumbling. So we award Nikon another 0.5 points. And now the score is tied (except that Eric is leading Steven significantly).

Score: Canon 2, Nikon 2, Steven -1, Eric 1

Light Leakage

Light leak through the viewfinder.  ISO 4000, 30 seconds

Nikon D600 Light leak through the viewfinder. ISO 4000, 30 seconds

In astrophotography and landscape astrophotography it is very useful to collect dark frames. A dark frame is a normal shot but with the lens cap on and the goal is to capture an image with stuck pixels or black level offset to fix other images taken with the same settings and at the same temperature.  Much can be learned about this in our BLOG.  Anyway, while shooting dark frames indoors with a capped lens, Steven was very distraught to discover that significant amounts of light can leak in through the eyepiece of the Nikon D600 and render the dark frame (or any high ISO night shot for that matter) unusable. Above is an actual shot. While it is true that light entering the viewfinder of a Canon 5D Mark II (and other cameras) can fool the metering system, Steven has never observed light leakage of the severity that the Nikon D600 displays.  Both Canon and Nikon offer eyepiece covers to solve this problem., but in truth, the cap doesn’t seem necessary on a Canon except when metering. Canon wins another point here.

Final Score

BoxingGloveCanon 3, Nikon 2, Steven -1, Eric 1

At a final score of 3 to 2 in favor of Canon does this contest feel like it has been rigged? Have you used both types of cameras? What is YOUR favorite feature or biggest pet peeve? Leave a comment!

Extraordinary Vision

Last month, one of Steven’s images was featured in the great (and free) Extraordinary Vision magazine issue 9 which is published online via iTunes.  

I_305-0347This month in Extraordinary Vision issue #10 you’ll find 17 pages of instructions on finding and photographing the Milky Way. If the article seems familiar, it is! The Extraordinary Vision article is an updated and combined version of our three-post series on the Milky Way:

If you haven’t checked out the magazine, please do – not just because of the Milky Way content, but because Angelo Ioanides does a fantastic job curating and writing great content. And it’s FREE – just like the content on our BLOG.

First page of the article.

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Click the image below to find the Extraordinary Vision Magazine:

Extraordinay Vision Magazine published on iTunes

 

 

 

 

What you Need to Know About Histograms

Original Publish Date: 11-September-2013
Last Revision: 11-April-2016

If you ask us what is the most potent tool a night photographer can wield, we’ll tell you: the histogram.  Unfortunately nearly all of the histogram information available seems to spend too much effort talking about what a histogram should look like and not enough time explaining what a histogram is… or that there are many different histograms and not all are equally useful. For example there are: luminosity histograms constructed from thumbnails created by the camera, there are color histograms created from the same thumbnails, and then there are luminosity and color histograms based on the actual sensor data – but those are rare. And of course there are still more histograms.

In the Beginning [41_03766]

In my early days I took what I thought was a fabulous photo of the fog creeping up against Mount Allison. It looked SO good on my LCD that I knew I was going to be in love with it. When I got home I realized that it was far from ideal. It was woefully underexposed and very noisy. That’s because I didn’t think to look at the histogram. At the time noise handling was not great and it wasn’t until recently that I was able to tease a half-decent image out of the data.

Deconstructing A Histogram

The best way to understand a histogram is to experiment. But before we launch into some experimentation, let me take a stab at explaining what a histogram is.

A histogram is a graph that shows the distribution of brightness (luminosity) over the range from the darkest possible to the brightest possible pixel.

Each vertical column reveals the number of pixels in the image that have that brightness level.  Usually the left edge is the darkest possible pixel – black – and the right edge is the brightest possible pixel – but there are some variations in histograms which we’ll cover in a moment.  Here is a degenerate, but perfectly valid histogram.

LuminosityHistogram_degenerate

A histogram showing only three brightness levels – nothing brighter than mid range.

In the graph above, we see that there are some (we don’t know how many) of the darkest possible luminosity.  A lot of pixels that are relatively dark – corresponding to the tallest line, and a few pixels in the “midrange” of possible brightness values at the next stubby little line. The image from which the histogram was made is this one:

BoringImage

A degenerate image composed of several primary colors.

Looking at the image, it is pretty obvious that the little bump on the far left of the histogram is the black frame around the border. The tall line in the histogram is the brown, and the little bump near the middle is the orange color.  What may be puzzling is that the orange looks pretty bright and you would not expect it to fall only about half way across the range from darkest to lightest values. In fact there IS clipping in the red channel – but we don’t see that in our luminosity histogram above! We’ll see why in a moment.

post-it-note-thIf one of the columns reaches the top of the graph it does NOT mean a “blow out” has happened. Likewise if a column appears at the right or left edge of the graph it does not mean that data has been lost or “blown out” – it does indicate that there MIGHT be a problem.

ColorHisto.bmp

At right is another histogram for the same data, 4 of them, actually. This was created using Photoshop’s “All Channels” view.

Rather than luminosity, the top histogram is in mode RGB showing each of the colors in this simple image against the maximum for that color.

The Red Histogram shows a complete range of reds from the darkest possible in the black border to the lightest possible. And here is where we first get a clue that quite a bit of the red is in the extreme right hand side of the histogram.  Most of the red is contained in the brown color.

The Green histogram shows the darkest possible green (i.e. black) and some green in the left 1/5th of the possible values, while the blue histogram shows only black and very dark blues.

Admittedly the image is not illustrative of a typical photograph of any kind. It does show clearly how the histogram corresponds to the values in the image.

HistogramLayersII.bmp

The image was created from additive layers using blend mode Linear Dodge ADD. Each layer has been constructed in different colors using the color value shown.  It is easy to calculate the majority of RGB triplets as: R=128, G=64, and B=32+16 (48).  The maximum values for an 8-bit image would be 255,255,255 – the value of the “whitest possible white” in this color space.

You might expect that the graph would reflect the 16-bitness of a 16 bit image. The maximum values for each color then would be 65,536, not 255 – but that’s not the way Adobe shows it.  A 65 thousand pixel-wide histogram would be beyond unwieldy.

Did you just have an “aha” moment?

One reason why the histogram is not completely trustworthy is that it is a composite of many luminosity values being lumped into one.  How so? Imagine possible values from 0 to 65,000 shown on a graph with only 255 different columns. A lot of “lumping things together” is present! It is possible to have lots of data in the darkest column and in the lightest column and still not have any blow outs or blacks.  Imagine it this way, suppose there were 100 possible luminosity values, but the graph showed just 20 columns.  The leftmost column would include values ranging from 0 to 4, the rightmost (brightest) would hold values from 95 to 99. So, in theory, you could have no zeroes and no maximums, but your graph would still show you data at each extreme.  This is where the histogram in Adobe Camera Raw is much more useful and accurate. Or to be more accurate, it’s not the ACR histogram that shows that much additional data, but it does indicate when items are being “clipped” – that is, reach the maximum or minimum.  But we’ll get to that in a minute.

In case you haven’t had another AHA moment, we want to explain why the histogram you see on your camera LCD should be regarded with suspicion.  That on-camera histogram is created from the thumbnail JPEG which is also shown on your LCD.  To go from raw data to a JPEG involves lots of operations including scaling 14 bits of information down to 8 bits, taking megapixels of resolution down to kilo-pixels and applying default curves and color assumptions. With that much data manipulation going on, your histogram reflects what your image MIGHT look like as a tiny JPEG and therefore may not accurately reflect what you’ve captured.

Get A Better Histogram: Use Lightroom or Adobe Camera Raw

Below is a much more useful histogram as found in Lightroom or Adobe Camera Raw. Your camera is not going to give you this level of detail- though you might have a highlight and/or shadows clipping indicator which we recommend you use.  ACR and Lightroom both offer shadow and highlight clipping indicators. Clipping indicators are enabled using the triangles in the upper left and right of the histogram or with the “J” key which toggles both indicators either on or off.  If you turn ON the clipping indicates by default blue dots replace clipped shadows and red dots reflect clipped (aka blown out) highlights.

First the wide view.

OverAndUnder_wide

Wide View: Shadow clipping (left arrow in histogram) turned on. BLUE indicates where the values have fallen to zero.

And here zoomed in:

OverAndUnder_zoomed

Zoomed in: We see both clipping in the shadows and highlight clipping (circled -though there are many more).

Notice how in the 1/4 view, we see much more shadow clipping! If we zoom in to 100% it will be even more obvious. As we adjust the exposure, shadows, contrast, highlights, blacks and whites the histogram and the clipping indications are reflected in real time.

Lightroom is also giving you a hint which colors are being clipped.  The blue triangle at the upper right tells you that the blue channel is causing the highlight clipping.  When multiple colors are being clipped, the triangle will include all the colors added together. Here the white triangle for the shadow clipping tells us ALL colors are zero – that is clipped in the shadows.  For this image moving the exposure to the right reveals that the green channel is the most clipped. 

Take Aways

  1. Don’t believe everything you see on the back of your camera display – especially not the image!
  2. Don’t only pay attention to the luminosity graph – it may hide highlight clipping in one or more colors. This is especially true, for example, if you take photos of red roses. You can cause the red channel to clip but the luminosity graph will look fine.
  3. Take a look at the color histogram if your camera has one.
  4. Just because you are taking photos at night doesn’t mean you can’t blow out the stars. Doing so means you’ll lose some color data, but it’s better to blow out a few stars than to have black for your foreground.
  5. Not every histogram (in fact most) won’t be “bell curves” – especially not at night.
  6. Oh, and please shoot in RAW. You keep a lot more of what you shoot that way!
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Clouds, Milky Way and Eerie Formations in Alabama Hills, CA

References

The Top 5 Night Photo Mistakes

Bixby Panorama

Intern: I would like to follow in your footsteps to become an executive like you. What is the most important thing I need to learn?
Executive: That’s easy, do not make mistakes!
Intern: But how do I learn not to make mistakes??
Executive: You learn best how to NOT make mistakes by learning from the mistakes you do make. Also pay attention to the mistakes others make. You won’t have enough time to make all those mistakes yourself!

So what are the most common foibles that you hopefully won’t have to make yourself when shooting at night?

  1. Failing to turn off AutoFocus. Unfortunately at night autofocus is usually not a help as many cameras will seek focus and not finding it, refuse to take a photo. Or just as bad, will hunt for focus, and settle on something that is way out of focus for each shot. In the same league: forgetting to check focus!
  2. Forgetting to format the Memory Card. You’ve got autofocus off, and you’re really excited about that timelapse or star trail so you get your intervalometer all set and start. Whoops. That card is nearly full so instead of hours of great stuff you’ll get minutes and a full card.  It is best to format the card in camera to avoid possible problems if the card was formatted on a computer or in a different camera.
  3. Omitting a check for tripod stability. Uh oh. If you blow this one, it might mean your camera falls over and smashes against the rocks. We’ve been horrified to witness such a spectacle on more than one occasion.  Or about as bad: your camera waves in the breeze and gives continuously fuzzy results.  Step away from that tripod and look from different angles. Is the center column vertical?  If you push in different directions does the tripod move? Did you forget to fully tighten the leg locks? Center column lock? Head? Check again, just in case!  Steven snapped a lens in half because his leg lock wasn’t snug and the camera simply collapsed in the direction of the unlocked leg.
  4. Neglecting to start the intervalometer.  If you’re using an intervalometer it’s not difficult to press the start button and walk away only to discover you really didn’t press the start button OR the intervalometer was locked in OFF mode so just completely ignored what you wanted to do.
  5. Wrong settings. It’s easy to do, you spent the afternoon getting perfectly framed milky-smooth waterfalls.  Now it’s night time and you set your exposure to 30 seconds, but you left your aperture at f/16 and your ISO at 50!  Ooops. Or you just took that super high ISO test shot … and in your eagerness to catch some meteors you leave the ISO in the stratosphere.

You’ll notice we didn’t mention:

  • Failing to take the lens cap off.
  • Forgetting to charge the battery.
  • Failing to bring memory cards with you.
  • Leaving the quick release plate at home.
  • Toting your camera bag up a mountain while your camera remains in your car.
  • Leaving the polarizer on…

We’ve done all of the above. You might find our “Stackers Checklist” helpful to avoid these pitfalls and many more. Many of our students carry laminated copies with them.

What was your most embarrassing or frustrating camera faux pas?