Tag Archives: Photography

Rain Can Teach Us Photography

Before I start the discussion, I would like to refer you to my previous posts because I have already covered this concept extensively:

https://dtmateojr.wordpress.com/2014/03/08/debunking-the-myth-of-full-frame-superiority/

https://dtmateojr.wordpress.com/2014/03/09/noise-performance-comparisons/

If you have read and understood those posts above then you can save yourself time by not reading this one…although I don’t mind if you do read this because this looks at sensors in a different perspective. I will try to cover some technical aspects in the form of analogies.

I noticed that not everyone who carries a camera actually understands photography so I’m hoping that my explanations here would help them. I will use rain as an analogy. I hope everyone has experienced rain and understands rain.

 

Do you know how they measure the amount of rainfall? They use a device called a rain gauge. It’s a very simple device and anyone can make their own. The simplest rain gauge is that of a basic straight container that looks something like this:

Image

All you have to do now is wait for rain over a period of time and then measure the height of the collected rainwater. Really simple. Now you might wonder why I did not specify any measurements. How big should the container be? Surely, a larger container will gather more rain! That is correct. A larger container will collect more rain but the rainwater level will remain the same. Why is that? Because a larger opening also needs to fill a larger volume. That’s why rain is measured in mm (height) and not ml (volume). Here’s a very simple math that explains this:

Volume = area of opening x height of rainwater

or

height of rainwater = Volume / area of opening

Notice that if you increase the opening you also increase the volume and the height remains the same. They are proportional.

What does this teach us about photography? The concept of a rain gauge is analogous to that of photographic exposure. First you have your container opening which is your aperture. Then you wait for rain to fall over a period of time which is your shutter speed. The proportion of the container opening to its volume is your f-stop. A rain gauge is like photography where everybody has agreed to shoot at the same f-stop. The measured rain level is your exposure and determines how bright the image will turn out. As we have mentioned before, the size of the opening is proportional to the volume and therefore the measured rain levels are the same irrespective of container size. Recall that a f-stop is the ratio of the lens focal length (container height) and aperture diameter (container opening). That’s why a f-stop is a f-stop. A f-stop is the same no matter how big your lens is. A 35mm at f5.6 will have the same exposure as 100mm at f5.6 although the latter has a much much larger opening.

It follows that if we use the same lens on different sensor sizes we get something that looks like this:

Image

The red circle is your lens’es image circle (area of rain). The rectangles in the middle are your different sensor sizes (rain gauges). From our rain gauge analogy above, you will realize that both sensors will have the same exposure (measured rain levels). A f-stop is a f-stop irrespective of sensor size.

Before you continue with the rest of the discussion, make sure that you understood the very basic concepts covered above because I will start explaining something that is often hotly debated in forums: sensor noise!

The full frame proponents will tell you that because of sensor size advantage over APS-C and 4/3rds and other “crop” sensors that it will have lesser noise and therefore cleaner output. The basis for this conclusion is the fact that larger sensors gather more light. Let’s discuss this in detail…

If you go back to our rain gauge analogy, it’s quite obvious that a larger container will gather more rain although the measured rain levels remain the same. Therefore a larger sensor will gather more light although the exposure remains the same. Now since noise is affected by the amount of light, therefore a larger sensor has lesser noise. Therefore, full frame is superior.

Well not so fast Pedro. A camera’s sensor isn’t really like a rain gauge. A sensor is actually composed of smaller components called sensels which are like smaller containers within a bigger container. It looks like this:

Image

So now we will have to narrow down our analogy to those smaller containers (sensels) instead of the whole sensor. You could probably see where this is going. You will notice light is gathered by the sensels and therefore noise is NOT affected by sensor size but by SENSEL size.

Again, sensor size does not affect exposure (rain level analogy). A f-stop is a f-stop (rain gauge analogy) and is not affected by lens focal length or sensor size. Therefore a smaller sensel will have the same exposure as a larger sensel. However, a larger sensel gathers more light therefore it will have lesser noise. This is why a 12Mp full frame has better noise performance vs a 12Mp APS-C sensor. This is also why a 12Mp full frame Nikon D700 has way better noise performance vs a 36Mp full frame D800 by virtue of the larger sensels. This is also why a 16Mp APS-C D7000 has the SAME noise profile as a full frame 36Mp D800.

And thus, we arrive at the following conclusions:

1. SENSOR size has no effect on exposure.

2. SENSOR size has no effect on noise.

3. SENSEL size ultimately affects noise.

Again, it follows from above that the same sensors will have the same noise profiles (e.g. Nikon D7000, Pentax K5/K5II and Nikon D800) even if the sensor sizes are different as long as they are exposed in the same way; same f-stop, same shutter speed. You will find shot comparisons between those sensors in http://dpreview.com and they are in agreement with the conclusions above.

Now you might have read from others about something called equivalency. They say that unless different sensor sizes are exposed equivalently then they will have different noise profiles. For example, a APS-C sensor with a lens set to 35mm/f5.6 is equivalent to a full frame sensor with a lens set to 50mm/f8. Although they have different focal lengths and f-stops, they are equivalent in terms of angle of view, aperture and depth of field, all because of the crop factor of approximately 1.5. While it’s true that AoV and DoF are equivalent, they will certainly have different noise profiles. Firstly, it’s quite obvious that if you use the same shutter speed, the 35mm/f5.6 will be overexposed by a stop. So if you use the same shutter speed, you will have to stop down the 35mm to f8 which will decrease the aperture size and somehow this will affect noise?! We know from the rain analogy and sensor design discussion above that this is simply UNTRUE! I don’t know why the equivalency proponents keep pushing this concept when photographically it does not make sense. This equivalency-fu is like using rain gauges that do not adhere to the same standards and they will end up looking like this:

Image

Notice that they have the same opening area of 6.25mm:

35mm / 5.6 = 6.25mm

50mm / 8 = 6.25mm

But because of this equivalency brouhaha we now have skewed rain gauges. Notice that you will have to gather rain over a longer period of time for the 50mm/f8 container to arrive at the same rain level as the 35mm/f5.6 container. Full frame proponents think that they are the standard so the illustration above would probably look like this from their perspective:

Image

So now the crop sensors will have to expose at a shorter period of time just so they could abide by the standards set up by the elite full frame shooters.

For me, this is just silly. I feel that all these comparisons between full frame and smaller sensors are nothing but silly justifications for the perceived superiority of a particular sensor. Discussing equivalency is fine as long as it’s still about photography. It’s ok if you explain crop factor in terms of AoV or DoF but when you start using this as a tool to push the perceived superiority of your more expensive equipment then it’s really just bullshit. Bullshit and downright very wrong and misleading. Stop it.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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N00bism #3

Hello world! This the third post of the N00bism series. I hope that the previous articles made you think about your own approach to photography. As I have mentioned before, this series aims to discuss the common mistakes beginners, and to some extent, even experienced photographers fall into. These are the same issues that I have experienced and/or avoided and have observed in my constant interactions with photographers of different levels of expertise.

Without further ado, let me discuss “premature manual mode”.

I have already written an article about this macho manual mode, or M mode as most photographers call it. It’s ok if you shoot in “M mode only” but puhleeze, don’t brag about it. It’s not rocket science. You do not have to tell the world about it because those who actually know how to use it will find your bragging quite underwhelming or laughable.

Those of you who are just starting with this expensive hobby should avoid using M mode. Trust me. I have been there. Allow me to explain:

Firstly, you bought that very expensive camera for what? It’s expensive because it is intelligent enough to do most of the work for you. You are wasting your money if you do not put it to good use. It has full automatic mode for a reason. Even the most expensive of cameras have auto modes. Auto modes make your life easier so you can concentrate on things that matter.

For newbies, what matters most is making the shot. You can have the most perfectly exposed shot but if your composition sucks then your photo sucks. Period. Why burden yourself with the exposure when you can’t even get your horizon straight? Why fiddle with those buttons when your shot is so hopelessly cluttered? Why shoot in M when you do not even understand exposure in the first place?!!!

Do yourself a favour. Use that green square mode and learn about composition before anything else. If you can’t help touching those buttons then leave your multi-hundred dollar DSLR and use your mobile phone instead. Yes, even if the “image quality” is inferior. A clean, crisp, 36Mp crappy shot is still a crappy shot.

So when should you start using the M mode? If you think that a better exposure will improve a good shot. It follows that you know what a good shot is. It also follows that you know what exposure is. If you can’t get a good shot with your mobile phone, your DSLR won’t help either. Because a good shot does not depend on what camera you use. In fact, more complicated cameras would probably hinder you from making a good shot.

I won’t cover composition here. It’s not something that you learn by reading. Yes, there are pointers like rule of thirds. Google them.

I will skip to the topic of exposure because that’s all this crazy M mode does anyway. Sorry but I won’t even discuss the exposure triangle here. If you do not understand that concept then you should not even be thinking about M mode. There are millions of web articles that discuss it and I won’t bother repeating them.

How do you learn exposure? By understanding light. Understand that during high noon on a very clear day, you will have the greatest intensity of light that you would normally encounter. I said normally because you might want to shoot directly at the sun or capture an exploding atomic bomb. Anything else would just be varying intensities of lower magnitude. This high noon light is often called “sunny f16”. It simply means that the correct exposure for a subject under bright sunlight is f16, 1/ISO for a given ISO sensitivity. For example: f16, 1/100 at ISO 100. We usually “round off” the shutter speed to the nearest “whole stop”, which is 1/125 for the above example. An example of light with lower intensity is when your subject is hiding under a shade to avoid the harsh sunlight. In this instance, light intensity drops by at least 4 stops so your exposure would be f4, 1/125 at ISO 100. Sometimes I give it f2.8 just to be safe.

It’s not enough that you know the different light intensities. You should understand contrast as well. In the above example, if you want the subject in the shade to be properly exposed then everything outside that is lit by the sun will render as white. If you want to properly expose what’s outside then your subject will be barely visible under the shadows. In this example, no amount of screwing around with M mode will help you. The argumentative folks will probably say, yeah shoot at f8 then pull the highlights and push the shadows in Photoshop. Whatever.

You see that it’s not enough that you know shutter speed and aperture and ISO to warrant the use of M mode. Because if you do not undertand light you will end up screwing around with those knobs until your camera’s LCD tells you that you have lined up the exposure slider dead in the center. You are basically wasting your energy following what the camera is telling you. M mode has become the automatic mode for stupid people. M as in moron mode. Shoot in full auto instead.

So beginners, please learn to compose first before confusing your brain even more with M mode. And experts, there’s no need to brag about it especially if you are just lining up the sliders.

N00bism #2

Welcome to the second installment of the N00bism series. This time I will tackle probably one of the most highly debated aspect of digital photography. Note that I am very specific about “digital” here and you will see why in the next few blocks.

The topic I am about to discuss is the use of UV FILTERS.

Let me tell you right now that this is probably the biggest scam in the history of photography. Every sales person would sell an unsuspecting buyer a UV filter together with the entry level DSLR and kit lens. Sometimes they would even make them feel that they just made the greatest bargain by giving them a free UV filter after they sold the last remaining stock of last year’s entry level DSLR model.

Well actually, let me take that back. This is not the scam. The scam is when a buyer is forced to feel that they need the most expensive UV filter to pair with their very expensive lens. Let’s see: you already spent thousands of dollars on that lens so why ruin the image quality by screwing a cheap UV filter?! Doesn’t make any sense, no? So you buy each of your holy trinity of lenses the best UV filter you can find. Now THAT makes a lot of sense.

Or does it?

Back in those days when the word photographer actually meant something — back when people shot with film — a UV filter was part of the arsenal. Film is sensitive to UV light and that actually made the photos look cold and hazy without them. Photographers used UV filters because they do help make the photos look clearer. Not so with digital photography. Digtal cameras are corrected against UV light. Yes, your DSLR has a built-in UV filter. You do not need another UV filter.

But wait, UV filters are meant to protect your lenses!

Ok, so now you know that it’s useless as the accessory it was meant for so let’s discuss this positive side effect of doubling as a lens protector. Does it really protect your lens?

Let’s put this in proper context. What kind of protection do you expect from it? Protection against impact? Please consider the fact that a UV filter is just a very thin piece of glass bound by some metal screw mount attachment. Even a very light knock will scratch or break it because it is what it is: a very thin piece of glass. A serious knock will break the glass AND bend the metal mounting and ruin the thread of your lens’es screw mount. You’d be lucky if you can still unscrew the broken filter from your lens without further ruining your lens. It’s not really much of a protection, no? Use your lens cap and/or hood if you want real protection.

So how does the front element of your lens compare to a UV lens in terms of toughness? Firstly, it is so much thicker so it won’t break that easily. Glass is actually a very tough material. To cut through glass, you need the world’s toughest natural substance: a diamond! In the very unfortunate circumstance that you do break the front element, a UV filter would have not been able to save it either. If you do break the front element, expect that something in your lens’es internals would be broken as well due to the force of impact. The point is, don’t be stupid.

How about minor scratches? Front elements are quite tough buggers. You would think that lens manufacturers would consider fortifying this most exposed part of the lens, yes? And even if you do scratch it, you would have to scratch it very very badly before the effects would even start to show in your photos. I’m serious. If you don’t believe me, then check THIS

What about dust? Doh?! Just clean your lens with a cloth. If dust gets on your lens then surely a UV filter will get dusty too so what’s the deal? Even dust INSIDE your lens won’t affect your photos. I have a few old manual lenses with dusts in them but they still make very good shots.

Allow me to summarize those points: a UV filter does not provide enough protection. Your lens is way tougher than any UV filter. Minor lens blemishes do not affect image quality.

So enough with what a UV filter does NOT do. What does a UV filter do really? Unfortunately, nothing but negative 😦

Firstly, it causes flare. Some have lesser effects than others but when subjected to point light sources, UV filters will cause flare in images. This is especially true when shooting at night with light sources coming from different directions.

Secondly, with UV filters glued to your lens, you can’t attach other filters (that do matter) without causing image degradation. Stack a CPL and/or an ND filter in there and you will have bad vignette.

Thirdly, you are just supporting the scammers by buying expensive UV filters.

And that’s it folks! So now you have another method of detecting n00bs — they are the ones with UV filters on their lenses.

N00bism #1

In the next few blog posts I will try to cover some of the most common newbie mistakes that even a lot of experienced photographers fall into. I expect that not everyone will agree with my observations and opinions but I hope these posts will make you seriously think about what you are doing.

So numero uno (#1) in this list is ULTRA SHALLOW DEPTH OF FIELD.

Most newcomers to DSLR photography have this wild obsession on shallow depth-of- field. It’s quite understandable because point-and-shoot (P&S) cameras have very small sensors such that everything from the foreground to infinity are in focus all the time. They don’t want that anymore. Those everything-is-in-focus shots look very amateurish. They want their subjects to “pop” and look pro. It won’t be long before they learn new terminologies such as “bokeh” and “fast lens”, and start the endless craving for expensive, heavy, wide aperture telephotos.

Those who have the money are the first ones to post portrait shots where only the eyes are in focus, the nose blurry and the ears barely recognizable. Their 85/1.2 lens has made the human subject look like a puppy with ears folded back waiting for a good pat on the head. I mean, come on…why the heck did you even waste your time looking for a “nice location” for the photoshoot when the background in all your shots all look like a big blob of blurry mess?!!! You might as well cut and paste your subject into a pre-made wallpaper image. The conflicting ideas are just too funny: they want a nice location but aim to blur everything except the subject.

Look at how real pros do it. Watch them use the background to complement their subjects. Good backgrounds add context to the image. They shoot at f5.6 or f8 and some even shoot at f16. If they do have to shoot at f2.8 they would normally step all the way back to achieve enough DoF.

And it’s not just with portraiture. Macro n00bs do this as well. The lenses focus very close to their subjects and they shoot at 2.8 such that they can’t even get one eye in focus. Stop down to f16 or f22 for Pete’s sake.

I haven’t stressed this one enough but I have always thought that reliance on ultra shallow DoF is for those who can’t compose a shot.

I’m not saying that portrait shots with nice blurry background don’t look good. They do and that’s why everyone is doing it, n00bs included. Especially if you are an experienced photographer, if most, if not all, of your shots look like this then what’s separating you from all the newbies?

Think about it.

On Ken Rockwell

Why oh why would I even write about Ken Rockwell?

He is easily one of the most hated in the industry. That’s why.

If you haven’t read or heard about him then you are one of the lucky few. It probably means you are out there shooting instead of lurking in forums and hurling shit at other “photographers”. Some forums even have strict rules of “no KR discussions”. Some “togs” are very quick to tell n00bs not to read Ken Rockwell.

But WHY?!

Here’s my own conclusion based on common observation: Those who hate him are primarily jealous gear heads who can’t stand the blunt opinions of KR.

Hey, Rockwell isn’t perfect and some of his views are kinda outrageous. Consider his opinion on not using tripods for example. I’m not sure if he is just masochistic but I will bet my unused Nikon D700 that I can take better photos than him if we go on a one-on-one photoshoot contest on the same location as long as he doesn’t use a tripod. I can guarantee that I will have more keepers and more interesting shots than him. Does that make me a Rockwell hater? Far from it. Have a read on his other articles especially those that tackle composition and FARTing and why your gear does not matter. Every newbie should read them. If you visited Rockwells page and totally missed his excellent tutorials then there is no denying that you are a gear whore. Yes, Rockwell is a gear head. What differentiates him from other gear heads is that the guy can shoot. Compare him with FroKnowsFoto or Kai of DigitalRev (if you don’t know them then consider yourself lucky for the second time). Compare him with those “photographers” who hate him. If you don’t believe me then check out his gallery at 1x.com. Now try submitting your own shots to that group and see if you can even get one image approved by their expert curators. Gear whores, on the other hand, think that Rockwell can’t shoot. Guess what, he owns everyone’s dream gear. So if you think that he can’t shoot then truly gear does not matter if you suck at photography. So touche. Every gear whore who hates him is shooting himself on the foot. Gear heads hate him because they can’t beat him. Rockwell is everything a gear whore wants to become but can’t. Rockwell can buy any gear he wants yesterday. Heck he could probably get any camera before they are even released. I said BUY. Not borrow. Kai or Fro don’t even own the gear they “review”. Rockwell BUYS his gear. He buys them and make very blunt reviews about them. Fan boys will kill anyone who makes blunt criticisms about their chosen brand. That’s why they hate him. Gear whores feel like Rockwell just told them that their mothers are ugly. They feel that it’s cool and that it makes them more credible if they hate Rockwell. They can’t accept the fact that after they upgraded to the latest and greatest camera and acquired the holy trinity of lenses their photos still suck. Rockwell was right after all!!!

I’m not saying that Rockwell is God but some say he is the Chuck Norris of photography. If you have not read about that then consider yourself unlucky. It’s easily one of the funniest posts I have read.

I’m not saying you should believe whatever Rockwell says but he is more credible than any other “photography” magazine when it comes to gear reviews. It’s quite funny because there won’t be Rockwell haters if they did not visit his website frequently. How could you hate someone at first glance? You have got to be a frequent visitor to develop a hatred for the guy. These same gear whores keep coming back for more! And rightly so. Rockwell is easily one of the most honest reviewers out there unlike magazines who are scared to say something bad for fear of being abandoned by gear manufacturers.

So you really hate Rockwell? Then I would like to see your photo gallery.

It’s Not Real

I have been asked so many times if my photographs were “real”. I hope that whatever triggered them to fire that (sometimes insulting) question was because my photos looked good.

Are they real?

No, they are not. The camera always lies. The photographer always lies.

A good photographer will hide the stuff he does not want you to see, while at the same time, emphasize and even exaggerate the stuff he wants you to see. They only show you their side of the story and make (or force) you believe in that story. That’s what every good frame of photograph does. There is nothing more to explain. The rest is up to the viewer whether he agrees or not.

Photography is actually the opposite of reality. Sure you can make good photos in good weather but it’s the worst of weathers that produce the best images. More often than not, the worst situations result in pulitzer shots. How I wish I could say the same for reality.

Essential Settings for Landscape Photography

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(An HDR image of Salamanca harbour in Tasmania)

I have been asked about what settings I use when shooting landscapes. It’s no secret but depending on the camera and lens that you use, you may have to use different configurations.

Let me start by saying that I use my Pentax K5 for most of my landscape shots because it does everything I needed it to do. My lens of choice is a cheap Sigma 17-70/2.8-4.5 which you can buy brand new for about $300. I like it’s very flexible range and the focus markings in the barrel.

Without further delay, let me go through my camera settings.

0. Always use a tripod. It will slow you down to think about proper composition. You want to get it right the first time if you can. Of course it will also allow you to shoot at low ISOs and smaller apertures. If you decide to be lazy then stop here; landscape photography isn’t for you.

1. I use aperture priority mode when shooting landscapes. It allows me to keep on shooting even when the light conditions are changing fast without the need to constantly adjust my exposure settings. The only time I use full manual mode is when I’m stitching panos or when doing exposures longer than my camera can handle (i.e. more than 30 seconds).

— Aperture priority mode does not always get the exposure right. When the luminance of the sky and land are almost the same or when there’s only a stop or two of difference between them, say, after the sun is down, I tend to do exposure compensation of +1 stop to maximize the available light (ETTR concept). I also do this during blue hour. If unsure, check your histogram.

2. Set your camera to the lowest NATIVE ISO required to make the shot. Native ISO is not thefake extended ISO values. Most cameras have ISO 100 or 200 with extended ISOs being 50 and 100 respectively. Extended ISOs use some whacky tricks inside the camera that may be detrimental to the images that you capture.

— ISO values are a bit tricky to manage and how you handle them depends on your camera. Note that noise is affected by ISO sensitivity and length of exposure. You will have to test this with your camera. Do not be afraid to shoot at a higher ISO if the scene calls for it. I have been in situations where I have pushed my camera to the limits by shooting at ISO 6400 for 30 seconds. The result was worth it:

PK5S4012-ppg

3. Know your lens’es sharpest aperture. It’s usually around f8 when shooting wide or f11 when zoomed in. The difference in aperture compensates for the focal length. At f11, APS-C sensors will start to experience softness due to diffraction but by zooming in, you force the aperture blade to open up to maintain the same f-stop thus allowing you to maximize the center of your lens without suffering from diffraction issues.

— Having said this, don’t be afraid to shoot at f16 or f22 if the scene requires it, say, you want to force a longer exposure to blur the water. If your shot is good enough, people won’t notice the insignificant blur caused by diffraction.

4. Manually focus to your hyperfocal distance. This is something that even experts tend to ignore. Most people rely on autofocus. Learn to hyperfocus because it will save you when your lens starts hunting when the light drops or when you use very dark ND filters. If your lens does not have focal distance markings then you will have to estimate. Read my tutorial on hyperfocusing here.

5. Turn off any image stabilization feature of your lens and/or camera. This means Canon IS, Nikon VR, Pentax SR, Sony SSS and so on. Image stabilization will cause blur because it will try to compensate for movement that isn’t there. This is a feature that is meant for handheld shots and is destructive when shooting on a tripod.

6. There are several choices on how to release the shutter but the best option is to use mirror lock up mode (MUP). MUP will flip the mirror up before opening the shutter curtain to avoid camera shake. Especially that sensors are getting denser, the effects of mirror shake become more noticeable. When using MUP mode, use a shutter release cable to avoid touching the camera. You will have to click the shutter twice: once to flip the mirror and then to open the shutter curtain.

— Your second option is to use the camera timer. This is handy in the absence of a shutter release cable. Set your timer to two seconds or whatever option is available for your camera. This will allow any movement in the camera to settle down after you press the shutter before taking the shot.

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The rest of the settings I will outline below are entirely optional and might be very subjective.

7. If you need to bracket, set the exposure intervals to at least 2 stops. That means -2, 0 +2 for a three-shot bracket. Anything narrower than that is kinda useless because a one-stop gap can easily be recovered from a properly exposed single RAW image.

8. Save both RAW and JPG copies of your shot. Although RAW is very flexible, JPG will save you a lot of retouching time later on. This assumes that you get it right in the camera as close as possible to your intended result. Shooting JPG benefits those who would rather spend time shooting than being in front of the computer.

20121218-202043.jpg

(JPG capture looks fantastic if you get it right in camera.)

9. That UV filter is useless unless you are shooting film. Digital sensors have built-in UV filters. UV filters will only cause unnecessary flare and prevent you from using filters that do matter like a CPL or an ND filter for example. If you really want to protect your lens, use a hood instead; it will also protect you from flare instead of causing flare.

20121218-202059.jpg
(CPL filters will give you nice saturated colors. This is straight JPG from camera.)

So that’s it. Very easy to follow settings that will hopefully make a difference to your landscape photos. Until next time.