Wednesday, April 10, 2013

Macro Photography Basics - Part 2

Macro Photography Part 2


Hello, this is the second half of my blurb on macro photography. If you are familiar with the concept & please read on. If youre a beginner wanting to get a better understanding of the basics, please feel free to read the part 1 of my macro photography article.

In this part, we cover more on Lenses, Accessories, lighting, & basic Techniques around aperture selection, iso, shutter speed etc.

Macro lens vs Front Adapter Rings vs bellows units vs Lens Extension Tubes

So a big question Im asked is, whats the best option.
The fact is that it really depends upon your budget, how much of your photography is macro, & analysing your cost vs benefit, like everything else.

I recommend you start by using the lens reversal idea, see if it sparks an interest, & if it does, go for a cheap macro lens.

Screw on macro adjustment rings:

The screw on front objective rings are great if you want just a little bit of magnification on your average cheap kit 18-55mm lens, but dont expect anything significant.
Be very careful of using these on internal focus lenses lenses where the focal point throughout the focal length. I read a long article on it & got myself confused, but basically, avoid using these little rings on lenses like the popular 18-200mm VR etc. It will not work well at most focal lengths & often have focus errors etc

Macro Extension tubes

Extension pieces come in 2 variants, the cheaper ones that dont support exposure metering/AF, & the more expensive ones that are supposed to support metering.
Increasing the distance between your lens & camera reduces the minimum focus distance thus allowing you to go closer to your subject, simple as that. You can try it out by holding the lens in your hand to get the idea.

I feel that if youre buying extension tubes, you might as well buy ones that support exposure metering, otherwise, why not just use the lens reversing & make do.
In my opinion, no point spending on tubes that dont have metering support.

Saying that, some extension tubes come in sets & can cost about that same as a cheap prime lens.
That brings us to our next idea:

Lens on Lens reversal:

One of the oldest ways to do macro is to take 2 50mm prime lenses & reverse one onto the lens on your camera.
You can just hold the lens, or buy a $20 filter thread objective reversal ring off eBay.
You get full AF & metering.

Best to ick an older style lens that has an aperture so that you can keep the aperture open as big as possible, say f1.8.

It is best to do this on a prime that has no extension of the front objective during focus, otherwise AF will not work.
But even if it is the cheaper type which does extend in & out, the metering is there & you get more magnification from this technique than any tube or lens reversal ring.

But, it potentially is prone to aberration or other optical issues in the picture, distortion, fish eye etc tend to happen. Still not bad though.

I prefer the simple single lens reversal as its more manageable, not too heavy, inexpensive & very good image quality.

How to select a macro lens:

Magnification Ratio - Maximum Reproduction Ratio - How Ratios work:

The terms magnification ratio & maximum reproduction ratio for any lens are the same thing.
Its nothing more than the actual size of the object vs the size it will be when measured on the image sensor.

1:1 means that the image on the sensor will be the same size as the object itself.
1:2 means the image will be half the size.

It is common to confuse the second number & assume that 1:2 means double, it doesnt.
Remember 1:2 means half. You should divide the first number by the second number to get your actual magnification.
Some lens models were more user friendly & stated the magnification as a number like 0.25, or 0.5.
0.5= 1:2 & 0.25 = 1:4, etc

These numbers are listed all along the barrel on a macro len, pretty usually in a similar way as the focus distance numbers. You will usually see them start around 1:10, & then work their way down to 1:1 or so.


What you should look for:


1:1 magnification is considered bare minimum for a 'macro' specification, ie, a lense that will re-produce the image of the object on the sensor thats the same as the real object thats visible in your photo.
But cheaper macro lenses can be 1:2. These are not to be dismissed, & you can screw on an adapter that will bring them to 1:1 performance with minimal image quality change.

You can also connect any of these to a teleconverter, a 2x doubler which also provides a noticible increase in image size.

Digital SLR technology has come a long way, & a good sensor means you can crop & achieve a resultant image size with the crop ratio that will provide you comparable detail to 1:1 magnification or better.

But, do not confuse dslr sensor crop ratio & image cropping manually done as being 1:1 magnification.


This brings us to the next topic on focal lengths.

What focal range & f-stop lens should I buy - 100mm 60mm 40mm 200mm!?

The lesser the focal length, the closer you will need to go to the target subject to achieve the big image size on the sensor. It is important you understand this because it impacts your picture angle & field of view much the same as you would think of in any application of photography.

If you have a very wide macro lens, youre going too close so the parallax of whats behind the object is significant. The narrower lens, the less you need to get closer, so your object may look more uniform.
But then you wont get the effect of feeling 'sucked into' the macro photo.

Get this right, for it will impact every photo you take. There is no right or wrong answer, it just means your images will look a certain way everytime.

My recommendation for macro is that if you want a lense thats macro as well as versatile, then a 60mm is ok. If you want a lens that is really for close up macro, go with at least 100mm.

If you want something for specialist medical photography etc, people use the 200mm all the time. Thats when you need to read an article written by an expert in that field :)
If you want to do specialist macro but are a beginner, I suggest you start with basic macro ideas like those in this article, but then work your way up.

How to start off:


People usually start with the usual suspects, flowers, small insects etc, but really, its whatever captures your fancy.
Having seen my attached photos, some will make you wonder what they are.
You too can try to capture subjects where the viewer would wonder what it is that youve captured!

Common Myths which are incorrect:


Personally, I use 100mm on a DX sensor camera. Again, remember, this doesnt mean that the magnification of my macro lens is 1.5x of the number shown on the barrel, thats incorrect.
The magnification always stays the same no matter what format camera you use with a lens that is compliant to your crop sensor.

Some people like to take a photo at a certain magnification, then crop say 50% worth of  the image off, & argue that the results are the same as a lens that would have twice the focal length. In digital, cropping & pixels have opened up the avenue for greater actual image size in pixel, but this must not be confused as being greater macro magnification.

Greater magnification in reality should be measured by how close a lens lets you go to the tinies of subjects, & then how much that tiny subject is magnified.

Enlarging large subjects & getting relative large image sieze is not the point of macro photography.
As I said before, if I take a photo of an animals head with a zoom lens & then crop it so that only the eye is visible, I cant argue that its 2:1 macro magnification, even though there is good resultant magnification, that is NOT macro by any measure.

To conclude, as long as you go close to the subject & take a photo, you are in the macro world.

Thanks for reading :)

Was this tutorial useful, & was it easy to understand?

I write these articles in the hope of them being better than other complex content out there so please let me know if this was useful, or not so that I can make them bettter in the future.

Happy Shooting :)

Macro Photography Basics - Part 1

The basics of  Macro Photography - An introduction 

What is Macro:

Macro or Micro, whatever you call it, is about capturing subjects that are small.
Essentially, for something to be classified as a macro photo, the usual impression is that the camera was brought quite close to it.
Though its not mandatory that the lens be in the subjects face, that is what the usual implmentation of macro photography starts off as.

Thats why, if you take a photo from a good distance & then crop it to death, that 'zoom' doesnt necessarily qualify as macro photography.

Forget about zoom, cropping & dslr crop ratio, true macro is about getting your hands dirty with the subject from as close to it as possible in most cases :)

Its about capturing detail that would otherwise be impossible with other techniques or equipment.


How do I start - Macro Equipment

Do I really need a macro lens:

Well folks, the great news is, No, you dont!
You dont need a macro lens, but it makes life easier than using other contraptions.
I recently came across cheap lenses like a Promaster Spectrum 7, which provide excellent image quality for an entry level price.

AF is not always that big a deal. Its nice to have but quite often useless.

f2.8 on a macro lens is practicaly useless for true macro.
With closeup macro photography, your depth of field is already not deep enough, because you're so close to the object that at any given point, almost everything behind the focal plane is significantly out of focus.
So more often than not, you will need to stop down to f10 or lower, even f16, before you get sufficient depth of field to capture details.

Yes, f2.8 lenses are great because you can then use them as your everyday prime lens instead of carrying your other prime lense around, but personally, I would not be overly concerned by a macro lenses maximum aperture.

A good macro lens will give you a sharp precise picture, especially when its closer to the minimum focus distance of the lens.

Macro lenses have very small minimum focus distances usually, ie the closest your lens can be to your subject in focus with average lenses today is around 50cm, with a macro lens, its often close to 5cm. Thats just an example, because back in the old days when most lenses had minimum focus distance of 200cm, a lens with 50cm was considered macro too! How the times change... :)

If not macro lens, then what

My favourite is the lens reversal concept.
Investment cost: 0 You dont need to spend any moey.
Almost every photographer has at least 1 lens that can be reversed & will act like a very simple macro lens.

The best option for that is a 50mm f1.8 type cheap simple prime lens.

For a start, just detach the lens from your camera, turn it around, & hold it against your camera.
Viola!

Yes its manual focus, manual metering, manual everything - welcome to the 1950s.
But hey, its free & works a treat :)


Find macro interesting, please read more in my Macro Photography Part 2 article here.

Was this first part of the article useful, & was it easy to understand?

I write these articles in the hope of them being better than other complex content out there so please let me know if this was useful, or not so that I can make them better in the future.

Happy Shooting :)