Thursday, December 30, 2010

In-Depth Review: Tokina 100mm f2.8 AT-X PRO Macro

The Tokina 100mm f2.8 ATX-PRO Macro

Tech Specs
Focal Length: 100mm
Dimensions: 3.75” x 2.9”
Weight: 19 oz.
Maximum Aperture: f2.8
Minimum Aperture: f32
Diaphragm Blades: 9
Front Element: non-rotating, extends about two inches
Optical arrangement: 9 elements in 8 groups
Autofocus Mechanism: Micromotor (Canon version)
Closest Focus: 11.6 inches
Maximum magnification: 1:1
Filter Size: 55mm



Background
For people who like to get up close and personal with their photography, the 100mm macro is the Goldilocks of macros in that it allows more working space than the 50mm versions and costs a lot less than the 150mm and up lenses. Besides having the perfect balance of performance and price, 100mm offers great potential as a portrait lens, too. In short, because of their usefulness, mid focal length macros are very popular lenses.


Build Quality: 4
Tokina is a company known for its high standards of construction and the 100 f2.8 AT-X PRO Macro doesn't disappoint here. Yes, the lens is plastic, or in Tokina lingo, polycarbonate, but it is built very well for a lens made of such materials, having a very dense feeling to it. As is the norm for most maro lenses, the front element is deeply recessed into the lens barrel. Moving into the mechanics, it's all good. The focus ring is absolutely buttery smooth in its movements and there is no slop to speak of at all. To switch from AF to MF, simply snap the ring to the indicated position at any time you like as there's no need to find the “window” as was required on some old Tokina lenses. Well, snap may be a bit of a misnomer, as the ring can be moved virtually silently. When it comes to focusing, the lens will extend about two inches when focused at its closest distance. As a final touch, this lens incorporates a distance window. In all, the lens is very solidly put together, especially for one in its price range.

The lens extends about an inch at closest focus. Here it is with the hood, too.

Autofocus Operation: 5

The Tokina 100 f2.8 AT-X PRO Macro does not feature an ultrasonic drive, but the conventional micromotor/mechanical drive, depending on your make. Yes, while it may not be a sonic drive, the Tokina is still an extremely good performer when it comes to AF. On my Canon 30D, focus is always spot-on, even with fast moving subjects like flying birds! Oh yes, speaking of birds, the tracking abilities of this lens are stunning as well, especially considering that macros are often bashed for the tendency to have slow AF. In terms of sound, the lens is extremely quiet for a micromotor and should be inaudible except to people standing right next to the photographer using it. All in all, when it comes to the AF capabilities, the only thing the Tokina macro lacks is its ability for full time manual override, other than that, this lens is almost as good as a sonic lens in terms of speed, accuracy, and sound. As an added bonus, Tokina was good enough to equip this lens with a focus limiter switch.

Focus limiter switch, AF/MF clutch settings, and distance window.





Despite being powered by a micromotor, AF is speedy enough to do birds in flight without missing.


Optics: 5
One advantage of a fixed focal length lens is that the job of the optician is easier because performance at only one focal length is of concern, which means that cheap primes often outperform expensive zooms. Because macros need to focus so close, they have a reputation for containing some of the finest optics on the market. Let's see how the Tokina 100mm AT-X PRO Macro does.

Center sharpness is wonderful. 

Corner sharpness on APS-C leaves nothing to be desired.

Sharpness

When it comes to sharpness, the Tokina is a top performer right out of the gate. Wide open at f2.8, the lens is as sharp as it will get and this sharpness extends from corner to corner, to boot. Stopping down will only extend depth of field, which is vital at macro distances. On a crop camera, the lens starts to hit the diffraction limit by f16. Unfortunately, not owning a full frame camera, I can't provide any insight as to how this lens would perform there.


Distortion
Being a fixed focal length, and on top of that, a macro, the Tokina has no distortion whatsoever.




A pleasant surprise: no vignetting whatsoever!

Vignetting
There is no vignetting on APS-C.



Chromatic Aberration
Tokina lenses have a reputation for having high-levels of chromatic aberration when shot wide open. The 100 macro lives up to this trend, with the CA being the weakest link in the optical chain. However, even in the most extreme situations, the CA virtually disappears by f4, which is good.



Try as I may, I can't get the lens to flare even without a hood.

Flare/Ghosts

When it comes with the ability to resist flare/ghosts, the Tokina macro has two things going for it: a recessed front element and an included hood. Even without the hood, try as I may, I just can't get this lens to flare.




The deeply recessed front element undoubtedly helps prevent flare/ghosting.



Unlike Canon lenses, the Tokina comes with a hood included. As an added plus, note the pinch style front cap, you can remove it with the hood in position, unlike the crappy Canon front caps that require hood removal.

Value: 5
Going to show that you can get more than what you pay for, the excellent performance and $400 price of the Tokina 100mm f2.8 AT-X PRO Macro make it an absolute steal. As of this writing, the Tokina is the cheapest 100ish macro on the market, edging out Sigma and Tamron lenses and blowing away the manufacturer versions in terms of price. Really, the only question for anyone who has even the slightest money concerns is why one should not buy this lens. Unless sonic-drive AF is a must-have feature, there's simply no reason to buy anything else.


In the Field:
With its 100mm focal length and fast 2.8 aperture, the Tokina 100 f2.8 AT-X PRO Macro has a lot of photographic potential. First and foremost is the true 1:1 macro capability, whose results must be seen to be believed. If you've never shot a macro before, be prepared to be blown away as small spiders transform into hairy beasts, yarn becomes rope, and scuffs on coins become deep gouges. Thanks to its fast AF, this lens also has potential for indoor sports and anywhere portraits, provided that a faster focal ratio isn't required to separate subject and background. As a last bit, the short telephoto length can be great for general walk-around shooting, too.














All photos are the original image (top) and 100% crops (bottom). Oh, yes, those pictures of the fiberish material is a closeup of yarn. If you ever wondered what 1:1 reproduction plus all of those pixels on a modern digital camera can do, here's your answer.



Set the focus to infinity and forget it! Note: no CA at f4, either.


Astrophotography
The Tokina 100 f2.8 AT-X PRO Macro is a great astro lens as infinity is infinity. So, no need to fiddle with the focus, just manually focus to infinity and enjoy the tack-sharp stars!



Competition:
In terms of competition, the 100ish, f2.8 macro is a very common lens as just about everyone makes such an optic. Needless to say, competition is fierce, especially considering that the optical differences in macro lenses are pretty much nil in that all of them are good. So, when it comes down to the basic 100mm macro, the only real deciding factor will probably be price, in which category the Tokina is king. Now, when it comes to add-on features, choosing could be more difficult as some of the latest macros incorporate sonic drive motors and/or stabilizers. Unfortunately, these add-ons demand a major price increase that will leave many people asking “do I really need that?” When it comes to the sonic motor, my advice is to skip it as modern micromotor lenses perform very well and for the reason that manual focus is best when shooting macro as it allows the photographer ultimate control over the point of focus. The stabilizer? Well, that can come in handy, especially when lighting is not good. However, if you want the stabilization so you can shoot narrower apertures, consider this: the diffraction limit of the lens itself. Most lenses will start to soften between f11 and f16. So, think about it, is that you need or just want that stabilizer? Unless you're loaded, my advice is this: skip the stabilizer, too.



Conclusion: 4.75/5
In conclusion, the Tokina 100mm f2.8 AT-X PRO Macro is an excellent lens in itself that gets even better thanks to the unbeatable $400ish price tag. The build, AF capability, and optics are all pretty much top-notch and the focal length and fast aperture combine to turn the macro into a great all-around lens, too. The bad, well, there really isn't any. The addition of a metal barrel and sonic motor are really the only things this lens could use, but, these additions would undoubtedly jack up the price a bit, though. In conclusion, this lens is proof that it is still possible to get more than what you pay for. So, for anyone considering a macro lens, I would highly encourage you to look at this one first!



Tokina 100mm 2f2.8 ATX-PO Macro + Camera = Loads of Fun!




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Wednesday, December 29, 2010

November 2010 Astrophotography

Well, it's been a long time coming, but here, finally, are Novembner's astrophotos. The month was actually pretty good at the start and, thanks to a clear October, I've managed to get pretty much all of the winter biggies I had yet to shoot over the years. As always, enjoy.

Orion's Sword


 The Crab Nebula in Taurus


 M37 in Auriga


 M41 in Canis Major


 The Moon and a giant "star"



 The Moon, hand-held!


Venus in the morning, nearly -5 magnitude!




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Saturday, December 25, 2010

The Planet of Bethlehem?

The Star of Bethlehem was probably a planet.

One of the greatest mysteries of the Bible and astronomy is the Star of Bethlehem, which guided the Magi on their journey to the baby Jesus. The description of the star in the Bible leaves a lot of questions, and just as many possible answers to its true identity.


One problem, by far the biggest, must be confronted right before we can even start to narrow down the possible identities of the star: no one knows exactly when Jesus was born. Our current calendar is based on the birth of Christ. Unfortunately, this is wrong. It is now thought that Christ was actually born in the span of 8 to 4 B.C. In the Bible, the Holy Family fled into Egypt to avoid the wrath of King Herod, who died in 4 B.C. Thus, that year is the last possible year in which Jesus could have been born.

Now that our time frame has been narrowed down, we can start looking to the sky. There are two schools of thought about the Star of Bethlehem: it was either astronomical or astrological.Astronomical possibilities include supernova, planets, comets, and conjunctions. In the year 7 B.C., there was a conjunction of Jupiter and Saturn. However, this is very unlikely as the planets were about a degree (little finger at arm's length) apart. Unless the Magi had very poor eyesight, there is no way that two planets this far apart could be mistaken for a single object. Comets have been suggested, especially since they were often described as “hanging” in the sky. This is exactly as the Star was described in the Bible. A last possible interpretation is a supernova. A bright object was seen for about 70 days in 5 B.C. By Chinese and Korean astronomers. This may just be it, but there's a problem: the star was described as moving, which leads into the other school of thought: astrology.

People at this time were almost universal believers in astrology. A notable exception here were the Jews, who were forbidden to practice astrology at numerous spots in the Old Testament. As far as everyone else was concerned, heavenly bodies had special meaning.

One thing we know was that the Magi came from the East. Considering the geographical location of Judea, “East” almost certainly meant Persia. In Persian language, the word “magi” referred to Zoroastrian priests, who practiced medicine and magic (“magic” comes from “magi”), which could also include astrology, at which the Persians were very sophisticated.

One particular passage in Matthew can greatly narrow down possible candidates for the true Star of Bethlehem. According to the Gospel, “the star which they had seen in the East went before them till it came and stood over where the young Child was.” If this is to be believed, the Star was a planet. Over the course of months, a star's position will change as it rises about four minutes earlier each night. Stars don't stand still, but planets do.

Observe a planet over the course of a year, noting where it is in the constellations. For most of the time, it moves forward. However, there are times where it stops, reverses course, stops again, then continues forward. This apparent change in direction called retrograde motion is an optical illusion caused by the Earth passing the slower planet as both orbit the Sun. A comparison can be made to passing cars on the highway. As you pass, the slower car seems to travel backwards. The same is true of planets.

Besides retrograde motion, there is more. Planets and constellations had different significances. Jupiter was widely considered to be associated with kingship. The constellation of Aires the ram was often associated with Israel/Judea. Putting this information together with the knowledge that the Star of Bethlehem was almost certainly a planet allows one to start putting the puzzle together.

In 6 B.C., an astronomical/astrological event that fits the bill very nicely occurred. In that year, the planet Jupiter (planet of kingship) moved into the constellation of Aires (the constellation for Israel/Judea). Thus, this could be interpreted as a sign that a new king of Israel was born. To add even more weight to the hypothesis, Jupiter first appeared as a morning object in the East. At this time, the Sun was also in Aires (Jupiter was rising just ahead of the Sun). In astrology, any constellation is at its most influential when the Sun is in it. Also, it was believed at the time that planets were at their most powerful as they emerged in the East after a period of invisibility in the Sun's glare.

As it would have taken the Magi months to reach Bethlehem from Persia, this also explains the motion of the Star. As time progressed, the Magi could have observed Jupiter slow down and stop before going into retrograde motion. The stoppage could have coincided with the arrival of the Magi in Bethlehem after stopping in Jerusalem and being told of the prophecy predicting the Messiah's birth there.
This is by no means more than a hypothesis. The Star of Bethlehem will probably never be conclusively explained. Either way, Merry Christmas!




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Tuesday, December 21, 2010

Do We Have Exactly 2 Years To Live?

The Caracol: ancient Maya observatory.

Do you realize what day it it? If you didn't, it's December 21, and according to some, we all have exactly 2 years to live as, come this date in 2012, the world will be destroyed by some as yet unknown worldwide cataclysm.

Ah, yes, the 2012 doomsday fears arise again, but are they founded in fact or fantasy?

Okay, before we start examining where the fear came from and whether we should even worry at all, let's run through the 2012 doomsday scenario first. On December 21, 2012, the Maya Long Count calendar runs out. Now, while no one has used the Classic Maya calendar in hundreds of years (the great Maya civilization in Southern Mexico/Central America collapsed around 1000 A.D.), some people read some ominous overtones into this whole idea of time just running out, which has lead some to believe that, since they were the only civilization with a calendar that ever ended at a fixed point in time, the Maya knew something that no one else did: the exact date the world would end.

Now, that's 2012 as told by the fear mongers, what about 2012 told by science and history?

Understanding the whole 2012 doomsday fear requires a mix of Maya history and religion, which will then come together quite elegantly in the end. First off, Maya religion was in itself quite a convoluted mix of mythology, the most important of which was the myth of the Hero Twins, as this story told of the triumph of life over death that just may be the basis for 2012.

The Maya, so far as we know, were the first people to possess rubber, which they used for, among other things, molding into giant balls (about 10-12 inches in diameter) that were used in a ceremonial ballgame that represented the triumph of life over death by recreating the myth of the Hero Twins. As for the story, it went as follows.

A Maya ritual ballcourt. Note how high the hoop is on the wall.
Way back when, perhaps at a time when the game was more about fun, a Maya king and his brother liked to play the ballgame, the object of which was to knock the ball through a hoop high on a wall without using one's hands or feet. Obviously, with the useful appendages out of play, the game could go on for days, with the first team to score winning. Unfortunately for the king and his brother, their ball court was just over an entrance to the underworld and the sound of the heavy ball bouncing all over the place started to irritate the Lords of Death, who also just happened to be ball players. Getting fed up, the Lords of Death invited the king and his brother to the underworld for a game. Accepting the challenge, the king and his brother entered the realm of the dead and squared off against, and lost to the Lords of Death. The king and his brother were then sacrificed. However, the story wasn't done: the king had twin sons of his own, who also liked to play the ballgame. In time, just like their father and uncle, the twins ball playing annoyed the Lords of Death, who then decided that they were going to try and go 2-0 against the humans. Long story short, the twins beat the Lords of Death, sacrificed them, and then resurrected their father and uncle as the Sun and Moon, respectively, thus, life triumphed over death.

A highly stylized representation of the Milky Way void as a monster swallowing the souls of the dead. A copy of the coffin lid for king Pacal the Great.

Onto the astronomy, the Maya were perhaps the greatest astronomers in history until the Renaissance, with achievements to their credit that still stun modern scientists. However, like the Greeks, the Maya were an interesting people in that they made the most accurate astronomical measurements of their day, yet still clung to mythologies characteristic of far more primitive peoples. For the Maya, one facet of this mythology was the idea that the Milky Way was the road to the underworld and a dark rift in the Milky Way itself right above the famous Teapot asterism was the actual gateway. Okay, fine, so what?


Back to the Hero Twins myth. Remember that the Twins resurrected their father and uncle a the Sun and Moon. In releasing their father (now the Sun) from the underworld, the twins were creating, according to the Maya, a “new Sun,” or cycle of life. Now, back to the ballgame. While no one knows the exact symbolism involved, there is agreement on the idea that the ball represented the Sun. So, if the ball represented the Sun and the players the Hero Twins and Lords of Death, it only makes sense that, by the winning team knocking the ball (Sun) through the hoop, they were thus representing the Hero Twins resurrection of their father as the Sun by shooting the Sun out of the underworld through the gateway, represented by the hoop on the wall. Now, back to astronomy. It just so happens that, due to precession of the equinoxes, the location of the Sun on any given day against the background sky changes over time. Now, perhaps one of the Maya's most remarkable astronomical achievements: on December 21, 2012, the Winter Solstice Sun will rise exactly in the center of the dark rift in the Milky Way, symbolically rising out of the underworld and representing a new cycle of creation, at least according to the Maya.

So, does this mean the world will end?

Ironically, for all the fear their calendar has created, according to the Maya, one cycle running out and another starting meant that the world could end, not that it would end. For a really interesting cosmology, one only has to look at the history of Maya timekeeping. The Maya (and other Mesoamericans before them) were interesting in that they believed that time was cyclical, not linear. So, being obsessed with cycles, it was only natural that that Mesoamericans started looking for them in nature. Being farmers, it was important for these early people to ascertain the length of the year to better ensure successful harvests. So, as every other primitive farming culture did, the Mesoamericans found the year to be about 365 days long. Now, for reasons unknown, the Mesoamericans used not one, but two calendars, the other being a 260 ritual one that was used for divination purposes. Now, here's the big unknown: which came first, the two calendars or the realization that they would line up exactly every 52 years? While the answer to that question will never be known (the Olmecs who developed it left no writing), the impact of the calendar would last for centuries, with the Maya taking it to new levels of sophistication.

As with some people today, the Mesoamericans found the notion of time running out to be a little unnerving. However, unlike today, this fear was held by the entire population. So, as the 52-year calendar round entered its final days, the priests would up the prayers and demand greater sacrifices in the hope that the gods would let the world continue to exist. Well, by looking at the fact that we're still here, those Maya priests must have been pretty good! Now, despite the fact that the end of the world had been successfully averted every time in the past, the thought of confronting doomsday every 52 years left the Maya rulers/priesthood (on whom the continued existence of the world hinged) uneasy. So, some unknown genius came up with a big idea: why not postpone the end of the world by finding a longer cycle of time so that we don't have to worry about it anymore? Well, the idea took off and, in time, the Long Count, which ran 5,125.25 years, was created.


The Maya were so obsessed with timekeeping that they even built calendars into their pyramids. This one has 91 steps on each side plus a temple on top (94 x 4 = 364 + 1 = 365).


By looking at the cycles contained within the Long Count, it quickly becomes apparent that the Maya had a true love of numbers and/or had too much free time on their hands. The breakdown of the units of time contained within the Long Count is a follows:

1 day = 1 K'in
20 days = 20 K'ins = 1 Winal
360 days = 18 Winals = 1 Tun
7200 days = 20 Tuns = 1 K'atun
144,000 days = 20 K'atun = 1 B'ak'tun
1,872,000 days = 13 B'ak'tuns = 1 Great Cycle (completion of Long Count)

Obviously, with the 5,125.25 year Long Count complete, the Maya must have felt more than secure in the knowledge that they would never have to worry about the world coming to an end in their lifetimes ever again, as if the gods somehow had to obey the will of man now that a longer time cycle had been created. Pretty funny, isn't it?

Okay, back to the present.

If you have made it this far, you (hopefully) have come to the logical conclusion that there was no way that the Maya could have predicted the end of the world as the Long Count is a human construction that has absolutely no basis in nature. Simply put, the Maya hated the prospect of having to worry about doomsday every 52 years, so they decided to create a longer cycle (the Long Count) so that they wouldn't have to worry about it anymore. So, come 2012 and the end of the Long Count, why worry? The world never ended at any of those 52 year calendar rounds, so why would it end now at the end of a Great Cycle? Answer: it won't, the Long Count means nothing and desperately needs to be confined to the realm of pseudoscience junk like astrology, tarot cards, and all other forms of divination, not a single one of which has stood up rigorous scientific scrutiny.

 
Oh, yes, here's the eclipse (or at least what the clouds allowed me to see of it . . . )



 
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Monday, December 20, 2010

Total Lunar Eclipse Tonight

Tonight, sky watchers all across North America will get treated to a total lunar eclipse that will be visible from beginning to end, no matter what time zone you live in! As a trivial note, this is the first time an eclipse has also occurred on a solstice since 1638, which also brought a lunar eclipse, and is only the second solstice eclipse in the last 2,000 years! With this being such a rare event, anyone who has a clear sky (or even a chance of a few clear breaks) should head out and take a look up at the Moon. So, instead of going on and on typing away about what you will be able to see, I'll just show you.


Below is the complete sequence of the October 27, 2004 total lunar eclipse, the lat one visible fro start to finish in Ohio that wasn't clouded out for part of the time. By the way, I took these pictures with a primitive Sony Mavica, circa 2000. Obviously, if this (even for it's day) digital dinosaur (it ised floppy discs for storage) could take pictures of the eclipse just by me aiming and shooting, a modern day digital camera should be able to do much better.
 
 










 
 
 
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