Megapixels

Twelve versus sixteen megapixels from two different micro four thirds cameras showing same pixel area.

Not all pixels are equal.

I say this, because it's true, if little understood by the non-photography enthusiast.  Understanding why all pixels are not equal is relatively easy explain but, and it's a big but, the explanation requires the willingness to come to grip with things like F-stops and ISO numbers.

F-stops are an abbreviation for the ratio between the focal length (the F in F-stop) of the lens and the size of the aperture and the corollary that one has to have larger lenses for larger sensors.  The F-stop numbers are actually shorthand for one over the number, so F2 is a bigger aperture than F16 because a 1/2th is bigger than a 1/16th.  Therefore the F-stop describes the size of the aperture that governs the amount of light that passes through the lens onto the sensor.  The squiggly math can be found here.

The thing to takeaway is that the more light you let through the lens the better, and bigger lenses let through more light, but everything has a price, which is that the lens is physically larger too.

Then there is the sensitivity of the sensor, which is described using what is called an ISO number.  The three letter abbreviation comes from the International Organization for Standardization, see here.  In short, it's a measure of how well the sensor reacts to light and it tells you how sensitive the sensor is.  But, the higher the number used comes at a cost in image quality – usually noticeable as visual artifacts when there's not enough light to resolve the image being taken.  Ideally what one is looking for is a sensor with a low number like 100 ISO that has a large range that goes up into the thousands.

However, all of the above is relative to the sensor size and the number of pixels it has.  So it should be obvious that a big sensor with the same number of pixels as a smaller sensor means that the pixels are not the same size, and worse still, the amount of light gathered by the lens falling on said sensor is not the same either (if that doesn't make sense – remember that big lenses let through more light through them).

The difference in the ability of a large lens versus a small results in some thing that's called equivalence.  A large frame, 35mm film equivalent film camera, that has an F2 lens will be letting in two stops more light than a micro four thirds camera (equivalent to a half frame from a 35mm film camera) fitted with an F2 lens; or if you prefer the micro four thirds camera's F2 lens is equivalent to a full frame lens at F4.

That's probably confused you unless you're already savvy with cameras and lighting. So what does this all mean for the non-enthusiast user?

Here's a handy-dandy table to confuse matters by over loading you with lots of numbers.

Click to see larger picture.

TL;DR:  The size of the aperture in relation to the size of the sensor matters.

So, if you're using your camera phone, which because it has a small sensor (the smallest frame size in the illustration above), and because a small lens effectively provides a wide angle of view, it will be easier therefore to take pictures of small objects and have more in focus.  But despite whatever the it says about the number of megapixels, because the sensor is so small, you'll be unable to produce high quality big pictures, which may not be a problem if all you do is post to the web.
 
Here's a simple illustration that compares the size of the sensor of a full-frame camera down to a smart-phone.  Here you can see the big difference there is is sensor size.

Now what this means, bottom line if you like, is that light is everything when it comes to taking pictures.  Also, bigger cameras capture more light, and don't be sucked into the more megapixels is better, if all things are equal, the size of the pixel really does matter when it comes to quality of your pictures.  This is what drives the image quality, which is also called picture noise comes. These are the artifacts or blurring you see when you enlarge a picture, which can be understood if you remember noise is defined by the ISO number of the camera.

TL:DR:  Lots of megapixels on a small sensor are not as good as less megapixels on a larger sensor because bigger pixels are better.

      

Camera Upgrade

My new Olympus OMD EM5 Mk2 Titanium.

After nearly five years of using my Panasonic Lumix DMC GF1 I'm upgrading my camera system.  I got this as a present from my partner for my birthday, which is today, and is a significant double-digit number.  I've been spoilt rotten and I love her for it.

The last time I talked about upgrading my camera system was here.  This is a big deal, because photography is a thing for me, like breathing is a thing – can't live without it.

Anyway, my new micro four thirds camera normal resolution is 16 megapixels.  Lots of reviews on the web.  But what attracted me to it was the fact that it can take 40 megapixel still life pictures through a clever multiple exposure trick that moves the sensor between shots.  It's a good thing.  Especially good if one wants to take high resolution pictures of small toy soldiers.

The difference between my new Olympus OMD and my old Panasonic Lumix is that the latter was a digital camera while the former is a computer that takes pictures.  Colour me over excited.  Fortunately, I have an after market manual to help me learn all the functions, and I can't wait to take some pictures with it and post them here.

So far I managed to set the time and date.  As the saying goes, I may be some time.
  

End of an Era: Photographic Meanderings

As is my wont I'm meandering a bit off the general theme of wargaming to talk about photography, as I've just bought a "new" secondhand camera off eBay.  This act has been quite unsettling in some ways, as it marks the end of me using a 35mm SLR (single lens reflex).  Though realistically this is more like the full stop that ends the sentence, one that has been left unfinished since 2002, which was when I last used my Pentax MX in anger.

When I came back into wargaming circa May 2008 I started to take pictures for a modelling thread that I have on the BattleTech Universe Form here: Workbench.  This required me to be able to post digital pictures, and for a time before I had considered buying a scanner and using film etc, but quite frankly the cost in time and effort, as well as money, just wasn't worth it.  I was lucky in that my partner lent me a Sony Cyber-shot DSC-V1 a 5 megapixel camera with four times optical zoom for me to use.

The shift from film to digital was quite interesting, because it turned me from an experienced user into a complete newbie.

Start of extreme photographic geekiness...

Below is a picture of my SLR system that centered around my Pentax MX, which I've owned for many years, having bought it in I think 1981 from new.  Over the intervening years I bought lenses for it and a spare Pentax ME body about twelve years ago.

As you can see above The black MX has a 2.5 FPS auto-winder, which was a big deal in the 1980.  This is actually my second one, as the first fell to bits and I bought a second hand replacement many years later, which has served me well ever since, and still works like new.

To the extreme left is one of the two original lenses I bought back in the day, a Pentax M series 100m F4 macro for taking pictures of models funnily enough.  Mounted on the MX is a Pentax M series F3.5 15mm super wide angle lens that I bought second hand, which I loved for its extreme 114° field of view.  In the middle is a second hand Pentax M*(star) series F4 300m, which again back in the day was the smallest, lightest telephoto lens of its generation.  On the ME (original ME not ME Super) is the other original lens I bought back with the camera, a Pentax M series F2.8 40mm pancake lens, which was the slimmest lens that you could get, and made the Pentax MX feel light weight and compact (for definitions of light and compact that today seem laughable).  Finally, on the far right is a Pentax M series F4 24mm wide angle, again bought second hand.

The reason I emphasize the second hand acquisition is because in their day these lenses were arm and a leg expensive, costing way more than the camera.  Needless to say I used this camera quite a lot over the years, and as my first degree was in photography I have a certain amount of technical competence.

It can also be said that I was a manual everything user, as I never saw the need for automatics and the purchase of the ME was a bit of an aberration given that all of my lenses have the capability of resolving more detail than high street commercially processed film can render, which was driven by the desire to have a cheap point and shoot camera.

End of extreme photographic geekiness...

So, it was a bit of a paradigm shift for me to get my head around the fully featured Sony Cyber-shot DSC-V1.  However, I did get to grips with it and have been taking pictures with it for the last three or so years.  Still haven't used all the features, like for instance the nightshot feature.  Not felt the need, as my main aim was to take pictures of my models, or pictures of full size vehicles etc.

Just for the record the above picture is the first taken with my new camera, which I'll come to in a bit.

This Sony model first came out in 2003 and was pretty dam good for its day.  It has a 1/1.8" (7.2 x 5.3, 8.9mm diagonal) CCD (charge coupled device; the thing that acts like a film in my Pentax) with 5 megapixels, and the lens is a F2.8/F4 zoom that can be stopped down to F8 (stopped down is when you make the aperture of the lens smaller that then gives you a greater depth of field, which is really good when taking pictures of small things).  You've seen the results here on this blog.

However, even with the lens stopped down to F8, using a tripod to compensate for the long exposure times, the fact of the matter is that I've not really been able to get the picture quality I want (namely close-ups of very small 10mm figures) that shows the work I've done in the best possible light.  So I took the plunge and bought a new second hand camera.

Above is my new Panasonic Lumix DMC GF1 that has a micro four thirds CCD (18 x 13.5, 22.9mm diagonal) that shoots at 12 megapixels.  The lens is a 14 to 45 F3.5/5.6 zoom that stops down to F22.  So this camera is big step up from the Sony, as not only does it have more megapixels, it also has a much larger CCD, which means better "quality" too.  Once I've got my head around all of the controls and set up everything to my satisfaction I shall be posting pictures using my new camera in the weeks that follow.