Apple101.TheDock ,Change, Add ,n Remove

Change the Position of the Dock

Mac OS X lets you customize the Dock in a number of ways.
If you choose Dock from the Apple menu and select Dock Preferences, a dialog will open giving you access to all of the Dock customization options.
Use them to:

• change the size of the Dock
• turn Magnification On (or Off) by clicking the check box and, if On, the degree of Magnification
• indicate where you’d like the Dock to appear
• select the effect (Genie or Scale) used to minimize a window
• check the Animate box, which makes the icon for an application bounce when you open it
• check the box to have Mac OS X hide the Dock when it’s not being used

Add an Application to the Dock

If you enjoy the convenience of the Dock, you can make it even more useful by adding items to it you use regularly. Here, for example, you’ll find two ways to add one or more applications to your Dock.
Let’s say you’re currently using Keynote ’08, your favorite presentation software, and would like to keep it in the Dock at all times. Right-click on its icon in the Dock, and select Keep in Dock from the contextual menu that appears.
Or try this option. Open the Applications folder, grab Text Edit, and drag it to the Dock. Next time you want to use Text Edit, just click its icon in the Dock.
You can use this method to add multiple applications just as easily. In that open Applications folder, choose Calculator and Dictionary, two handy utilities, and drag both into the Dock.

Remove an Application from the Dock

If you’d like to reduce the number of applications from the Dock, you can do so at any time. Simply grab the icon of the document, folder, or application you’d like to remove, and drag it out of the Dock. Release the mouse button, and the item will vanish in a puff of virtual smoke.

Apple 101. Get Dictionary Definitions in One Click

Get Dictionary Definitions in One Click

You’re using Safari to research a paper on climate change and you find the phrase “anthropogenic greenhouse gas concentrations.” What exactly does “anthropogenic” mean?
Here’s a fast way to get the definition of a word you’re not familiar with.

1. Hover your mouse over the word and right-click.
2. Choose Look Up in Dictionary from the menu that appears.
3. Mac OS X immediately opens Dictionary and finds the meaning of “anthropogenic” for you.

Stored in the Applications folder, Dictionary works with all Mac OS X applications.

Using Telephoto

You've probably heard that telephoto lenses are for enlarging distant subjects, but they're also a powerful artistic tool for affecting the look of your subject. They can normalize the size and distance difference between near and far objects, and can make the depth of field appear more shallow. Telephoto lenses are therefore useful not only for wildlife photography, but also for landscape photography. Read on to learn techniques for utilizing the unique characteristics of a telephoto lens . . .

300 mm telephoto lens - two cheetahs laying behind a log

OVERVIEW

A lens is generally considered to be "medium telephoto" when its focal length is greater than around 70 mm (on a full frame; see camera lenses: focal length & aperture). However, many don't consider a lens a "full telephoto" lens until its focal length becomes greater than around 135 mm. This translates into an angle of view which is less than about 15° across your photo's widest dimension. On a compact camera with a 3-4X or greater zoom lens, telephoto is simply when you've fully zoomed in. However, some compact cameras might require a special adapter in order to achieve full telephoto.

Regardless, the key concept is this: the longer the focal length, the more you will tend to notice the unique effects of a telephoto lens.

The above diagrams depict the maximum angles that light rays can take when hitting your camera's sensor. The location where light rays cross is not necessarily equal to the focal length, but is instead roughly proportional to this distance. The angle of view therefore still increases similarly.

Why use a telephoto lens? A common misconception is that telephoto lenses are just for capturing distant objects. While this is a legitimate use, there's a whole array of other possibilities, and often times distant objects are better photographed by simply getting a little closer. Yes, this isn't practical with a lion, but a pet or a person will likely appear better when they aren't photographed from afar. Why? The distance from your subject actually changes your photo's perspective, even if your subject is still captured at the same size in your camera frame. Confused? More on this in the next section...

TELEPHOTO  PERSPECTIVE

A telephoto lens is special because it has a narrow angle of view -- but what does this actually do? A narrow angle of view means that both the relative size and distance is normalized when comparing near and far objects. This causes nearby objects to appear similar in size compared to far away objects -- even if the closer object would actually appear larger in person. The reason for this is the angle of view:

Wide Angle Lens (objects are very different sizes)	Telephoto Lens (objects are similar in size)

Even though the two cylinders above are the same distance apart, their relative sizes are very different when one uses either a wide angle lens and telephoto lens to fill the frame with the closest cylinder. With a narrow angle of view, further objects comprise a much greater fraction of the total angle of view.

A misconception is that a telephoto lens affects perspective, but strictly speaking, this isn't true. Perspective is only influenced by where you are located when you take a photograph. However, in practical use, the very fact that you're using a telephoto lens may mean that you're far from your subject -- which does affect perspective.

Objects appear in proper proportion to one another.
Uses a 135 mm telephoto focal length.

This normalization of relative size can be used to give a proper sense of scale. For full impact, you'll want to get as far as possible from the nearest subject in the scene (and zoom in if necessary).

In the telephoto example to the left, the people in the foreground appear quite small compared to the background building. On the other hand, if a normal focal length lens were used, and one were closer to the foreground people, then they would appear much larger relative to the size of the building.

However, normalizing the relative size too much can make the scene appear static, flat and uninteresting, since our eyes generally expect closer objects to be a little larger. Taking a photo of someone or something from very far away should therefore be done only when necessary.

In addition to relative size, a telephoto lens can also make the distance between objects appear compressed. This can be beneficial when you're trying to emphasize the number of objects, or to enhance the appearance of congestion:

Exaggerated Crowd Density		Exaggerated Flower Density

left: 135 mm focal length - congestion of punters on the River Cam - Cambridge, UK.
right: telephoto shot of flowers in Trinity College, Cambridge, UK.

In the example to the left, the boats all appear to be right next to each other -- even though they appeared much further from each other in person. On the right, the flowers and trees appear stacked on top of one another, when in reality this image spans around 100 meters.

BRINGING  FAR  AWAY  SUBJECTS  CLOSER

320 mm detail shot of a parrot

Perhaps the most common use for a telephoto lens is to bring otherwise small and distant subjects closer, such as wildlife. This can enable a vantage on subjects not otherwise possible in real life. One should therefore pay careful attention to far off detail and texture.

telephoto sunset

Furthermore, even if you were able to get a little closer to the subject, this may adversely impact the photograph because being closer might alter the subject's behavior. This is especially true when trying to capture candid photographs of people; believe it or not, people usually act differently when they're aware that someone is taking their photograph.

Finally, consider this: since a telephoto lens encompasses a much narrower angle of view, you as the photographer can be much more selective with what you choose to contain within your camera frame. You might choose to capture just the region of the sky right around the sunset (left), just the surfer on their wave, or just a tight region around someone's interesting facial expression. This added selectivity can make for very simple and focused compositions.

LANDSCAPES  &  LAYERING

130 mm telephoto shot using layered subject matter.
Photo taken on Mt. Baldy, California.

Standard photography teaching will often tell you that "a wide angle lens is for landscapes" and "a telephoto lens is for wildlife." Nonsense! Very powerful and effective compositions can still be made with the "inappropriate" type of lens.

However, such claims aren't completely unfounded. Telephoto lenses compress the sense of depth, whereas wide angle lenses exaggerate the sense of depth. Since spaciousness is an important quality in many landscapes, the rationale is that wide angle lenses are therefore better suited.

However, telephoto landscapes just require different techniques. If you want to improve the sense of depth, a common telephoto technique is to compose the scene so that it's comprised of layered subject matter at distinctly different distances. For example, the closest layer could be a foreground set of trees, the subsequent layers could be successively more distant hillsides, and the furthest layer could be the sky, ocean, and/or all other seeminly equidistant background objects.

165 mm telephoto shot using layered subject matter - Mt. Hamilton, California

In the above example, the image would have seemed much less three-dimensional without the foreground layer of trees on the hill. Similarly, the separate layers of trees, clouds and background mountainside also give the first example more depth. A telephoto lens can also enhance how photography in fog, haze or mist affect an image, since these lenses make distant objects appear closer.

POINT  OF  FOCUS

For a given subject distance, a telephoto lens captures the scene with a much shallower depth of field than does other lenses. Out of focus distant objects are also made much larger, which enlarges their blur. It's therefore critical that you achieve pinpoint accuracy with your chosen point of focus.

320 mm focal length - shallow depth of field telephoto shot of a cat amongst leaves

In the above example, the foreground fence was less than a foot from the cat's face -- yet it appears extremely out of focus due to the shallow depth of field. Even a misfocus of an inch could have therefore caused the cat's eyes to become blurred, which would have ruined the intent of the photograph.

Fortunately, telephoto lenses are rarely subject to the "focus and recompose" errors caused by shorter focal lengths -- primarily because one is often much further from their subject. This means that you can use your central autofocus point to achieve a focus lock, and then recompose your frame without worry of changing the distance at which objects are in sharpest focus (see tutorial on camera autofocus for more on this topic).

MINIMIZING  CAMERA  SHAKE

A telephoto lens may have a significant impact on how easy it is to achieve a sharp handheld photograph. Longer focal lengths require shorter exposure times to minimize blurring caused by shaky hands. Think of this as if one were trying to hold a laser pointer steady; when shining this pointer at a nearby object its bright spot ordinarily jumps around less than for objects further away.

Simulation of what happens when you try to aim a laser pointer at a point on a distant wall;
the larger absolute movements on the further wall are similar to what happens with camera shake when you are using a telephoto lens (since objects become more magnified).

Minimizing camera shake requires either shooting using a faster shutter speed or holding your camera steadier, or some combination of the two.

To achieve a faster shutter speed you will need to use a larger aperture (such as going from f/8.0 to f/2.8) and/or increase the ISO speed. However, both of these options have drawbacks, since a larger aperture decreases depth of field, and a higher ISO speed increases image noise.

To hold your camera steadier, you can (i) use your other hand to stabilize the lens, (ii) try taking the photo while crouching, or (iii) lean your body or lens against another solid object. However, using a camera tripod or monopod is the only truly consistent way to reduce camera shake.

TELEPHOTO  LENSES  &  DEPTH  OF  FIELD

Note that I've been careful to say that telephoto lenses only decrease depth of field for a given subject distance. A telephoto lens itself does not have less depth of field. Unfortunately, this is a common misconception. If you are magnifying your subject by the same amount (meaning that they fill the image frame by the same proportion), then a telephoto lens will give the same* depth of field as other lenses.

*Technical Note: for situations of extreme magnification, the depth of field may differ by a small amount. However, this is an extreme case and is not relevant for the uses discussed in this page. See the tutorial on depth of field for a more detailed discussion of this topic.

The reason that telephoto lenses get the reputation of decreasing depth of field is not because of any inherent property with the lens itself. It's because of how they're most often used. People usually magnify their subject matter a lot more with telephoto lenses than with lenses that have wider angles of view. In other words, people generally don't get further from their subject, so this subject ends up filling more of the frame. It's this higher magnification that is what causes the shallower depth of field.

distracting out of focus background

However, a telephoto lens does enlarge out of focus regions (called "bokeh"), since it enlarges the background relative to the foreground. This may give the appearance of a shallower depth of field.

One should therefore pay close attention to how a background will look and be positioned when it's out of focus. For example, poorly-positioned out of focus highlights may prove distracting for a foreground subject (such as in the parrot example).

Jailbreaking iPhones and unlocking phones : LEGAL !!!!

Jailbreaking iPhones and unlocking phones in general have traditionally been activities that were, legally, in at least a grey area.

In fact, the opponents of such practices have long claimed that doing these procedures was a violation of the Digital Millennium Copyright Act (DMCA), and thus illegal. The DMCA did not allow for “Circumvention of Copyright Protection Systems”, which is the section that such procedures fall under.

Until now. The Librarian of Congress has revised the DMCA and the changes are very good news for phone owners, and rather bad news for the likes of Apple.

Let’s take them one by one.

In the case of jailbreaking, the objections that Apple had were related to its need to preserve the iOS ecosystem. The Register of Copyrights, however, concluded that since you have to have bought an iPhone in order to engage in jailbreaking, there is absolutely no risk that it would affect sales of the devices. In fact, this is a classic fair use case, and Apple is only concerned about its reputation, not lost sales. Apple claim that these activities harm the integrity of the iPhone ecosystem, and while that may be true, apparently it has nothing to do with copyright.

Apple’s other objection, that jailbreakers use Apple code, was also thrown out. It turns out that fewer than 50 bytes of code are used, out of a total of 8 million bytes of code, or approximately 1/160,000 of the copyrighted work as a whole.

So, from now on, jailbreaking is legal and a matter of fair use.

What is unknown at this point is if Apple and AT&T will be forced to accept warranty repair claims from people with jailbroken iPhones, but if that isn’t happening today, it surely doesn’t seem impossible in theory.

Next up, unlocking a phone is also legal now.

Unlocking is the procedure which aims to make the device usable on a carrier other than the one it was purchased from (and locked to).

This mainly applies to GSM-based networks, like AT&T and T-Mobile, where the use of SIM cards makes switching carriers and the unlocking procedure easier. In theory, this could also be applied to CDMA unlocking (for networks such as Verizon and Sprint), but it might be a bit trickier in practice. Because CDMA phones don’t use interchangeable SIM cards, the phone is practically ‘hardwired’ to the provider who sells them. To unlock a CDMA phone, some reprogramming is usually needed, and the carriers do not, as a rule, accept phones that they haven’t sold to run on their network. Which is a problem, because according to the DMCA changes regarding unlocking, the carrier that you want to switch to has to authorize your device for use on the network.

Be that as it may, this is very good news for mobile phone users and might unleash many more interesting tools on the jailbreaking and unlocking fronts. Hopefully the developers of such tools will have nothing left to fear and will therefore create better procedures and faster updates.

Shedding Light On Polarising Filters

Shedding Light On Polarising Filters



Well after doing a lot of surfing and gleaning information from many helpful people on POTN, I think I can now give back this info in one thread. Hopefully this will reduce the confusion for the next person who tries to research this subject.

So, you've purchased an ultra wide angle lens for your DSLR and you would like to buy a polarizing filter for it? Unless you've been down this path before, the many brands and models are extremely confusing. The questions of whether or not to go with warming, Kaesseman, slim, circular, linear, graduated... etc etc just makes it worse.

The major thing that everyone seems to be in agreement with, is that you should buy a good quality filter. "Don't put a $10 piece of junk on your several hundred (or thousand) dollar lens." The brands that I have read through many forums and reviews which have been recommended include B+W, Hoya, Heliopan and Kenko. I'm sure there are many others, but they seem to be mentioned by lots of people as being quite reliable.

The other agreed points are that with auto focus in digital cameras, you need to get a circular polariser; the linear polarisers can interfere with the autofocus. Also a filter with "multicoating" is a good idea, as these can be more effective in preventing lens flare (coupled with your lens hood of course).

The first big issue with ultra wide angle lenses and polarisers (possibly other filters too, but I did not research them in any detail) is the possibility of vignetting. From my understanding, this is because the lens is so wide, it perceives the shadow of the edge of the filter. (I'm sure someone will correct me if I'm way off base.) This is where the first debate begins: how wide a lens can we use a polariser on before this problem begins to occur? ie: Which lenses cause this concern; 10-22mm... or maybe the 12-24 lenses? AND does having different lens factors (ie 5D full frame vs the Rebel's 1.6) have a further effect on this issue? I don't know the answer, as there were many theories out there. Hopefully someone will test this theory. (or they already have and I just couldn't find them!)

The next part of the debate is whether or not a "slim" filter design is required. These are filters that are lower in profile, thus creating less of a "lip" out from your lens- and hopefully less vignette. They are generally more expensive than their "regular" counterparts.

Many of the slim filters out there have no front thread, which means you cannot stack lenses (which is debatably not neccessary anyway... more about that later) and more frustratingly, (for me anyway) you can't attach your normal clip-on lens cap. All of the filters with the no-front-thread-design that I looked at, provided you with a plastic slip-on cap. Reportedly, they don't stay on very well (I remember my G2 had one and it was constantly falling off- but it also had a safety cord) and are easy to lose. Many people have spoken very favourably of these filters and were able to tolerate the lens cap issue. One possible solution, is to have a lens cap saving device attached- basically a little plastic "dot" that sticks to the lens cap and then is attached to the lens via elastic. I've got one on my kit lens; very cheap to buy.
http://www.amazon.com/gp/product/B00...lance&n=502394

Just to give a comparison here (all filters quoted in 77mm):
The B+W 77mm Circular Polarizer (MRC) Multi-Resistant Coating Glass Filter is $144.95 at B&H.
The B+W 77mm Circular Polarizer (MRC) Multi-Resistant Coating Glass Filter Slim is $164.95.

Another filter type that was thrown into my selection pile, just to create more confusion, was the Kaesemann. As per B+W's blurb: "Kaesemann ("encased") filters are completely edge-sealed for maximum durability under extreme climatic conditions." Some of the other filter manufacturers (Heliopan for example) also make Kaesemann versions of their filters. One of the generous people on here suggested to me that it was a bit of overkill purchasing this for normal landscape/travel photography and I agreed that the extra cost wasn't worth it to me. Others might find the extra protection useful. FYI:
The B+W 77mm Kaesemann Circular Polarizer Glass Filter is $164.95 at B&H; and
The B+W 77mm Kaesemann Circular Polarizer Glass Filter Slim is $174.95.

Two other options I was able to find, was the "Moose" filter. http://www.moosepeterson.com/gear/moosefilter.html (also available on other vendors' sites) and the Hoya or Kenko Pro 1 filters.

The Moose filter (made by Hoya for a nature photographer) is a combined "warming" filter and polariser which has a front thread. The disadvantage is that if you don't want the warming effect, you can't separate it from the polariser. (For an explanation on "warming", check out the link above.) The other thing I could not find any literature on, was whether or not this filter is multicoated. If it is, then it could be a decent buy, because it "works on any lens up to 17mm and WILL NOT VIGNETTE regardless of which f/stop is used!" (quote from his site). Ah!- only 17mm. This filter still remains a bit of a mystery to me. The creator raves about it (as he would of course), but uses a Nikon D2X (1.5 crop factor) and lists the Nikon 12-24 as one of his lenses. Maybe he doesn't use his polariser below 17mm. Anyway, I wasn't able to find many reviews out there about his filters, but at $118.50 from B&H or $99 direct from his site, they're worth investigating further. As I had to make a decision tonight and make my purchase, I left it up to others to "run with the ball" if they're interested.

Now, onto the Hoya & Kenko Pro 1's...
These two are both slim filters, but they also have a front thread! condyk suggested the Kenko to me as he (and from many other resources out there online) believes that Kenko and Hoya are one and the same... and Kenko is cheaper. Unfortunately for those of us in the US of A, it seems that the Kenko Pro 1 is marketed here as "Hoya Pro 1" and marked up considerably. As far as I was able to figure out, the same filter is marketed in the UK, Hong Kong and Australia as "Kenko Pro 1". This info could be wrong, but all evidence I've been able to find points in this direction. FYI:
The Hoya 77mm Circular Polarizing Pro 1 Digital Multi-Coated Glass Filter is $194.95 at B&H.
I then found the Kenko on the link below for $108.95AU (approx $80USD):
http://cgi.ebay.com.au/Kenko-77mm-Pr...QQcmdZViewItem

Again, I cannot categorically say that these are the same filter, but if they are, then perhaps people with more time and patience than me could ship them over. Alternatively, if you live somewhere where the Kenko is available, lucky you! I read many favourable comments about the Hoya Pro 1, so taking everything above into account and unable to find someone who had actually tested the Tokina 12-24 with a normal sized polarising filter, I chose that one. FYI, I was able to get it from:
http://www.2filter.com/hoya/hoya_pro1_digital.html for $156.86 (normally $194.63). One of the forums I was browsing through pointed out you need to actually click on "order" to reflect any discounts they might have at that moment.

I was able to find one person who tried a normal sized UV filter on his 12-24, and apparently didn't experience too much of a problem with vignetting.
http://www.fredmiranda.com/forum/top...5396/0#2756574
Still not 100% convinced, I still bought the Pro 1. I would love to hear about peoples' actual experiences with any of the ultra wide angle lenses and these filters. The easiest thing of course, would be to walk into a shop and try this out, but none of the shops in my area stock anything!

One final note, I was really interested in ND graduated filters and started looking into those as a possibility. A pro pointed out to me that with digital, the only thing you can't duplicate in Photoshop (or similar software) is polarising. I found a fantastic tutorial for duplicating the ND graduated effect in Photoshop here:
http://www.fredmiranda.com/article_2/ I've been experimenting with it and it's fantastic! Many different effects, normally achieved through a filter (like warming for example) can be achieved through software- so save your dough for a good polariser!

Hopefully this dribble helps someone. I apologise if any of this is incorrect; I am by no means a professional and my intentions are only to prevent someone from going through the confusing headache I did. Maybe if there's anything to add or amend here, it could be made a "sticky" down the track; especially when some people have provided feedback of their own personal experiences. There are other variations on the examples of basic polarisers I mentioned and they can be much more expensive. I just focussed on the ones under $200 and went from there

Choosing a Macro Lens

Choosing a Macro Lens by Working Distance vs. Price


All macro lenses all brutally sharp, so there is little gained discussing/obsessing sharpness comparisons. Here's a different practical way to compare macro lenses: Consider working distances (WD) versus prices when these lenses listed are close focused at full 1:1 magnification:
60mm Canon = 10 cm WD @ $440
100mm Canon = 15 cm WD @ $480
150mm Sigma = 20 cm WD @ $620
180mm Tamron = 26cm WD @ $690
180mm Canon = 25 cm WD @ $1,300
WD 10cm.
Unless you need this 60mm EF-S macro for specific uses the 100mm Canon macro is a better all around WD value and flexible use for most people. The 60mm is limited to EF-S mount Canon cameras.
I carry this 60mm macro when working in the field with no tripod, as a portable, hand hold able macro that lets me use it a moderate shutter speeds without excessive camera shake blur, as part of a portable field travel kit. It is the only Canon macro that let’s you leave on the filter while using the 14EX or 24EX macro flash units.
If you vacation/travel with a wide angle (e.g., 17-40mm) and telephoto zoom (e.g., 70-200mm f/4) this 60mm becomes the lower light lens as well as the macro.
Those of us who respect Nikkor 60mm micro Nikkor waited a long time for Canon to make one, it just happens (sadly) to be EF-S mount.

WD 15 cm.
You only pay about $40 to add 5 cm of WD from Canon's 60 to 100mm macro lens. Due to floating internal elements, the Canon 100mm has a shorter than 100 mm internal actual focal length at 1:1, likely 70-80mm, maintaining a good field of view while providing 14.9 cm WD. This is a GREAT flexible lens. 5 cm is a big 50% WD distance gain.

WD 20cm.
Pay additional $140 for another 5cm WD step gained from the Canon 100mm to the Sigma 150mm. The Sigma comes with a hood, tripod mount, HSM auto focus with full-time manual over ride (I manually focus much of the time), making it an very good middle contender, if it fits your needs. It is the first Sigma lens ever I used that contributed something important to photography performance; not another a “me-too” price-point product. Sigma4Less.com sells it reasonable.

WD 25cm.
Step up and you pay an added $700 for the next (last) 5 cm WD gained between the Sigma 150mm and the Canon 180mm. This is an amazing optic, little diffraction even when stopped down to f/22+. Ultimate WD.
The longer focal length makes it much easier to compose shots by isolating subjects, eliminating clutter, and much easier to get the lens plane position parallel to where you want the maximum depth of field on the subject.
It's big and long and prefers to be used tripod mounted, except when "butterfly hunting." Works with Canon 1.4x teleconverter as a bonus. The last macro lens you’ll ever buy.

WD 26 cm.
The Tamron is the longest WD versus price value winner, but I did not use nor consider it because a lens filter adjuster may prevent using the MT 24-EX Macro Flash.


What is Working Distance?
WD is the distance from the FRONT of lens element to the subject when the lenses are focused at their closest focus 1:1 magnification. Macro lenses all focus continuously to infinity also, but we are only calculating close focus distance above.

Calculate WD
= published close focus spec for lens - lens length - distance between rear element and sensor or film plane (which is approx. 4.4 cm for Canon EOS camera system.

Light Loss
WD is a BIG limiting use factor (in addition to the full 2 f/stops of light loss @ 1:1 magnification), so get as much WD as you can afford.

If you're serious about macro, try not to buy a macro where the lens barrel length changes during focus. For casual macro users, this is OK (like carrying the old Canon 50mm f/2.5 in a pocket out for a hike).

More Fun at Less than Life Size
When we mean macro, we mean life size reproduction, (1:1) magnification or greater. There is loads of fun "close-up" photography at less than life size, say 0.25x to 0.70x (butterfly and dragonfly hunting range) that you can do with diopters, close focusing zooms, etc. A cheap Canon XXmm-300mm zoom with a Canon 500D ($140) +2 diopter makes a good butterfly hunter, providing about 0.4-0.7x depending on focal length.

Using a wide angle lens close-up enables “a thing in its environment” close-ups,” which are useful and popular.

Hope that helps. Jack

Normally, the common street opinion is, given lenses of similar optical design, the shorter the focal length, the greater the DoF, the longer the focal length, the more distance is compressed behind the plane of focus (less DoF). But this is way too simplistic, and does not hold up under macro close focus distances with floating element macro lenses.

In general:
1. It is a struggle to obtain enough DoF under macro conditions and the lens focal length is less important than framing angle on the subject, etc.
2. Choose a macro lens for its handling, working distance, FL field of view framing, alternate uses, and NOT for perceived DoF differences.

Why?
The relationship between lens focal length and DoF - at macro magnification - is not clear, and there is no guarantee that a shorter focal length macro lens gives more DoF where you want it in a photograph than a longer FL lens. In fact, under macro conditions, the differences between shorter and longer focal length lenses may have more to do with shifting the plane of focus in front or behind the focus point depending on lens focal length. And more to do with framing the subject.

PRIMES

Primes
• Canon EF 14mm f/2.8L USM
• Canon EF 15mm f/2.8 Fisheye
• Canon EF 20mm f/2.8 USM
• Canon EF 24mm f/1.4L USM
• Canon EF 24mm f/2.8
• Canon TS-E24mm f/3.5L
• Canon EF 28mm f/1.8 USM
• Canon EF 28mm f/2.8
• Canon EF 35mm f/1.4L USM
• Canon EF 35mm f/2
• Canon TS-E45mm f/2.8
• Canon EF 50mm f/1.0L USM
• Canon EF 50mm f/1.4 USM
• Canon EF 50mm f/1.8
• Canon EF 50mm f/1.8 II
• Canon EF 50mm f/2.5 Compact Macro
• Canon MP-E65mm f/2.8 1-5X Macro Photo
• Canon EF 85mm f/1.2L USM
• Canon EF 85mm f/1.2L II USM
• Canon EF 85mm f/1.8 USM
• Canon TS-E90mm f/2.8
• Canon EF 100mm f/2 USM
• Canon EF 100mm f/2.8 Macro
• Canon EF 100mm f/2.8 Macro USM
• Canon EF 135mm f/2L USM
• Canon EF 135mm f/2.8 Soft Focus
• Canon EF 180mm f/3.5L Macro USM
• Canon EF 200mm f/1.8L USM
• Canon EF 200mm f/2.8L USM
• Canon EF 200mm f/2.8L II USM
• Canon EF 300mm f/2.8L USM
• Canon EF 300mm f/2.8L IS USM
• Canon EF 300mm f/4L USM
• Canon EF 300mm f/4L IS USM
• Canon EF 400mm f/2.8L USM
• Canon EF 400mm f/2.8L II USM
• Canon EF 400mm f/2.8L IS USM
• Canon EF 400mm f/4 DO IS USM
• Canon EF 400mm f/5.6L USM
• Canon EF 500mm f/4L IS USM
• Canon EF 500mm f/4.5L USM
• Canon EF 600mm f/4L USM
• Canon EF 600mm f/4L IS USM
• Canon EF 1200mm f/5.6L USM

Zooms
• Canon EF-S 10-22mm f/3.5-4.5 USM
• Canon EF 16-35mm f/2.8L USM
• Canon EF 17-35mm f/2.8L USM
• Canon EF 17-40mm f/4L USM
• Canon EF-S 17-55mm F2.8 IS USM
• Canon EF-S 17-85mm f/4-5.6 IS USM
• Canon EF -S 18-55mm F3.5-5.6 USM
• Canon EF 20-35mm f/2.8L
• Canon EF 20-35mm f/3.5-4.5 USM
• Canon EF 22-55mm f/4-5.6 USM
• Canon EF 24-70mm f/2.8L USM
• Canon EF 24-105mm f/4L USM
• Canon EF 24-85mm f/3.5-4.5 USM
• Canon EF 28-70mm f/2.8L USM
• Canon EF 28-70mm f/3.5-4.5
• Canon EF 28-70mm f/3.5-4.5 II
• Canon EF 28-80mm f/2.8-4L USM
• Canon EF 28-80mm f/3.5-5.6
• Canon EF 28-80mm f/3.5-5.6 USM
• Canon EF 28-80mm f/3.5-5.6 II
• Canon EF 28- 90mm f/4.0-5.6 II USM
• Canon EF 28-105mm f/3.5-4.5 II USM
• Canon EF 28-105mm f/4.0-5.6
• Canon EF 28-105mm f/4.0-5.6 USM
• Canon EF 28-135mm f/3.5-5.6 IS USM
• Canon EF 28-300mm f/3.5-5.6 L IS USM
• Canon EF 35-70mm f/3.5-4.5
• Canon EF 35-70mm f/3.5-4.5A
• Canon EF 35-80mm f/4-5.6 PZ
• Canon EF 35-80mm f/4-5.6
• Canon EF 35-80mm f/4-5.6 USM
• Canon EF 35-80mm f/4-5.6 II
• Canon EF 35-80mm f/4-5.6 III
• Canon EF 35-105mm f/3.5-4.5
• Canon EF 35-105mm f/4.5-5.6
• Canon EF 35-105mm f/4.5-5.6 USM
• Canon EF 35-135mm f/3.5-4.5
• Canon EF 35-135mm f/4-5.6 USM
• Canon EF 35-350mm f/3.5-5.6L USM
• Canon EF 38-76mm f/4.5-5.6
• Canon EF 50-200mm f/3.5-4.5
• Canon EF 50-200mm f/3.5-4.5L
• Canon EF 55-200mm f/4.5-5.6 USM
• Canon EF 55-200mm F4.5-5.6 II USM
• Canon EF 70-200mm f/2.8L USM
• Canon EF 70-200mm f/2.8L IS USM
• Canon EF 70-200mm f/4L USM
• Canon EF 70-210mm f/3.5-4.5 USM
• Canon EF 70-210mm f/4
• Canon EF 70-300mm f/4.5-5.6 DO IS
• Canon EF 75-300mm f/4-5.6
• Canon EF 75-300mm f/4-5.6 USM
• Canon EF 75-300mm f/4-5.6 IS USM
• Canon EF 75-300mm f/4-5.6 II
• Canon EF 75-300mm f/4-5.6 II USM
• Canon EF 75-300mm f/4-5.6 III
• Canon EF 75-300mm f/4-5.6 III USM
• Canon EF 80-200mm f/2.8L
• Canon EF 80-200mm f/4.5-5.6
• Canon EF 80-200mm f/4.5-5.6 USM
• Canon EF 80-200mm f/4.5-5.6 II
• Canon EF 90-300mm F4.5-5.6
• Canon EF 90-300mm f/4.5-5.6 USM
• Canon EF 100-200mm f/4.5A
• Canon EF 100-300mm f/4.5-5.6 USM
• Canon EF 100-300mm f/5.6
• Canon EF 100-300mm f/5.6L
• Canon EF 100-400mm f/4.5-5.6L IS USM

Special
• Canon Macro Photo Lens 20mm f/3.5
• Canon Macro Photo Lens 35mm f/2.8

Ok, that is a lot. Now some fundamental questions needs an answer:

Why some lenses are L (Luxury) and some not?

To me it seems the answer is: if prime is L, it is either a specialty lens (14mm, TS-E, 180 macro), extremely sensitive to light (24/1.4, 35/1.4, 50/1.0, 85/1.2, 135/2) and it is expensive (yes, that must be one L requirement!) and intended to special target group with media visibility adding a big "I'm a pro" tag to the photographer, like all white long primes do. What must affect also is construction, distortion, colors, sharpness when open, low audible noise, fulltime manual focus, better optical elements, focus accuracy. DO is in itself an L level tag, so it does not need L. L may be very hard to manufacture and still have perfect quality control (this is why 50/1.4 is not L - it has lot of variance wide open and 50mm is probably the easiest one to manufacture).

If zoom is an L, it means it has same aperture on both ends (or a very small difference), USM, fulltime manual focus and good construction. Perhaps weather sealing, too.

Why should I buy new lenses at all?

Because I have a need which is not fulfilled by the ones I have. If flash shooting is ok to you, why get 2.8 lenses? If moving around is ok for you, why get zooms? If changing lenses is not an option due environment you're shooting is, why get primes? And vice versa. Perhaps you find that your currect lenses leave you with lots of unusable photos (not suitable for situation), or they do not deliver quality you require.

Who decides when "quality" is ok?

You do. Only you. And what you decide is governed by your experience. In time you will develop your eye to see more from image: quality of lines, bokeh, colors, distortion. You print bigger, you see more. You get more demanding assignments (less light, in more demanding environment with more demanding schedule. You start to think more of "look" than technical quality.

"Look"?

Mostly people talk about speed and sharpness. "Sharp lens is good lens". Evaluating sharpness is one of the easiest things you can do with an image. Sharpness is a good thing of course, but there are several other things which should be more important:
• can you achieve good subject separation?
• can you make backrounds smooth and unobtrusive?
• are colors natural or pleasing?
• can you capture the current light?
• can you improve (boost) the current light?
• can you express yourself though the camera with this lens?
• do you feel that the images taken with this lens look good?
• is there "3-dimensionality" or other hard do define experiences when looking the photos?
• do you feel that the photos you take look like your photos?
• can you do it better with this lens?
• and so on...

So do all L's have those qualities?

What qualities? Didn't I just say that YOU decide what qualities are needed. You decide the qualities, then look for lenses that can produce those qualities, you weight them and check what you can afford (or better advice is: do not buy compromise lenses, wait, save and by the real one later). Sigma 14 is one example of a my compromise lens (could not afford Canon) - Canon 28-135 IS I already sold.


One lens seeking story

I'm getting a new lens for 1D Mark II which should come in a month or so. Why a new lens? I have now:

Sigma 14 f/2.8
Sigma 20 f/1.8
Canon 35 f/2
Canon 50 f/1.4
Canon 70-200 f/2.8L
Canon 1.4x mk II extender

I shoot lots of people on work, indoors, street. I like very low light shots without flash, good subject separation and smooth bokeh. I have used mostly 50 and 70-200 just for those qualities.

A casual reader will immediately see I obviously lack a common short zoom (24-70). May be, but the reason I'm looking for a new lens is both practical and artistic:

When shooting portraits I have always felt 50 f/1.4 is the best lens for that (very nice at f1.8-2.5), but that I'm just slightly too close to subject when shooting. 70-200 is excellent, too, but not very "artistic" - better for live movement. So, as said obvious zoom choice would be 24-70 f/2.8L, or in primes (if based on sharpness and speed) it would be 135/2.

24-70 drops out of the list because in 1.3X camera it extends only 10mm over 50mm on 1.6X camera. And 2.8 is too little for that wide a lens: subject separation can not be done properly. I do not want "general" lenses. I other words I'm not looking a lens just for recording a certain focal lenght range.

So, what about 135/2? Nice bokeh, sharp. Works with extenders. Too long for small rooms, even with 1.3X camera. Too close to 70-200 in aperture and range. And even 70-200 at 2.8 is too sharp for some portraits.


100mm may be slightly too long, and I will get 100mm macro later so for now, I'll forget 100mm lenght now.

Then we come down to 85mm. That is the interesting focal lenght. 110mm FOV on 1D mark II (50mm = 80mm on 10D)

85/1.2L is there. But why pay mucho extra for that when you have the 1.8 version which is really sharp and nice? Let's evaluate that. I went to net, consulted Canon "Lens Work II" and came out with info that 1.2 is very usable with 1.2L, it vignettes some wide open (actually I like that), and that it is relatively slow focusing lens. I plan to use this for "art shots" - focusing speed is not an issue. What is very important to me is autofocus accuracy and it seems that the slowness of 1.2L's focusing is there because its accuracy is excellent. Although sharpness is not no. 1 issue for me I'm not saying I don't care about sharpness - 80/1.8 is not equally sharp wide open (actually on paper it is, but due to difference in optics that does not work so well in reality) - that matters. I care a lot about bokeh and subject separation ( which should be extremely good when 1.2 is also sharp and lens focuses accurately). Seehttp://www.wlcastleman.com/equip/reviews/85mm/ for one good test. More testing in http://www.techphoto.org/urllink.epl...canon/50_1.epl .

So, I decided to go for 85/1.2L. Ridiculously expensive, but the only lens that fills all my requirements. If it weren't an L, with same specs I would have chosen it anyway. I did not include a requirement "L" anywhere into my list. Merely because it has qualities that go beyond "normal" Canon decided to give it L tag. L should not be a requirement, but L is often chosen as a result of using both logic and feeling in the seeking process.

This was just one story how people end up bying L's. In the end it's all about YOUR requirements. Forget L, think about U.