f**s
发帖数: 968 | 1 链接在此：
http://www.kenrockwell.com/tech/8mm-f35.htm
8mm f/3.5 Fisheye
Pro-Optic, Samyang, Rokinon, Bower &c. (2009-)
© 2010 KenRockwell.com. All rights reserved.
Intro Specs Performance Compared Recommendations
8mm f/3.5 Fisheye, Pro-Optic Nikon AI-s version. enlarge. ($290, Korean, no
filters, 13.8 oz./391g). This one came from this link to it at Adorama (also
specifically in Nikon, Canon EOS, Pentax/Samsung and Minolta Maxxum/Sony
mounts). It also comes branded as Bower, also specifically in Nikon, Canon
EOS, Pentax/Samsung and Minolta Maxxum/Sony mounts. It helps me keep adding
to this site when you get yours from these links, too. Thanks! Ken.
April 2010 More Nikon Reviews Nikon Lens Reviews
Introduction top
Intro Specs Performance Compared Recommendations
Compatibility
I personally buy from Adorama, Amazon, Ritz, B&H, Calumet and J&R. I can't
vouch for ads below.
This is the least expensive fisheye lens on the market, and one of the best
for DX, Rebel, 7D and other non full-frame cameras. At just $290, it's a
steal.
It fills the entire rectangular frame with your curvy image. It's not just a
small circle, as with the Sunex 5.6mm.
Tubes. (Nikon D300 at f/11 and ISO 200). tubier.
This 8mm f/3.5 is softer wide-open in the center at f/3.5 than Nikon's
fisheyes, but by f/5.6, it's as sharp or sharper, and hs less lateral color
fringes than the exotic Nikon 8mm f/2.8 or Nikon 10.5mm 2.8 G.
This $290 lens is much sharper along the periphery than Nikon's exotic 8mm f
/2.8, which sells for ten times as much.
I prefer the projection of this Pro-Optic fisheye over the Nikon Nikon 10.
5mm f/2.8 G and 8mm f/2.8.
Unlike Nikon's Nikon 10.5mm f/2.8 G, this Pro-Optic lens has a dedicated
aperture ring to make exposure setting a breeze.
This 8mm f/3.5 lens is made in Korea and sold under many brand names.
This Pro-Optic lens comes in mounts for Nikon, Canon EOS, Pentax and Minolta
Maxxum/Sony. I will be discussing the Nikon mount as tested here, unless
otherwise called out.
Under the Bower brand name, it also comes in mounts for Nikon, Canon EOS,
Pentax and Minolta Maxxum/Sony. The Bower name costs more, and it's the same
thing, so we'll forget about it.
Compatibility back to intro back to top
General
The focus ring goes in the correct direction for each camera brand.
Focus is manual-only, which is the best for fisheyes.
On film or FX, you only get a smaller rectangle in the middle of the frame.
As shot on FX. enlarge.
If you cut-off the four front petals for FX, you'll get a mostly circular
image with the tops and bottoms cut off by your frame. Look carefully at the
image above, and you can see the ribs on the top and bottom which are the
lens looking at the inside of the hood petals. Have them chopped off, and
you'll get a big circle with the diameter as defined by the little rounded
corners above.
The petals do not come off, except via cutting or by force. They are very
solid and permanently attached.
If you remove the petals, there is no longer any way to attach the cap, or
then to protect the front glass element from anything.
This lens works swell on Nikon, whose cameras are designed to be backwards-
compatible with Nikon's own 1950s manual-focus lenses, but might not be to
your taste for Canon, Minolta or Sony.
On Nikon top
The manual-focus 8mm f/3.5 works great with most Nikon cameras. On the D200
and up, just set the "non-CPU lens data" menu to 8mm and f/3.5 for full
metering and EXIF. You'll get manual and aperture-preferred auto modes.
The meters of cheaper digital (D90, D5000 and below) and cheaper film
cameras (N80 and below) will not couple (or work at all) with this lens, so
you'll be on your own guessing exposure using the rear LCD or an external
meter, or get a tiny Gossen Digisix meter and hotshoe adapter to meter
manually.
Image size and cutting off the hood aside, it works flawlessly with every
manual focus Nikon ever made, from the F of 1959 through the FM3a and today'
s FM-10.
On the D3X, D3, D700, D300/s, D200, D2 and F6, use the "Non-CPU Lens Data"
menu option to set 8mm and f/3.5 to get full color matrix metering, EXIF
data and finder read-out of set aperture. It works great in aperture-
preferred as well as manual modes on these cameras.
It works perfectly on every professional film camera (F, F2, F3, F4, F5, F6)
, and even adds Matrix metering on the FA, F4 and F6.
See Nikon Lens Compatibility for details on your camera. Read down the "AI,
AI-s" column for this lens.
On Pentax and Samsung top
You can get Av (aperture-priority auto) if you set the lens' ring to A,
after which you control the aperture from the camera's control dial.
This description sounds sideways to me, but I'm presuming that this is the
same as using any other SMC-A lens on a digital Pentax.
On Canon top
The Canon EOS version mounts on every Canon autofocus camera made since 1987
, including all Canon's DSLRs.
The diaphragm is manual on these cameras. This means that you have to turn
the aperture ring to 3.5 to focus, and back to f/8 or whatever to shoot.
Since you focus by scale rather than through the lens, this means you can
leave it set to your shooting aperture and simply suffer a dark finder image.
There are no electronic contacts, so it doesn't really work well on Canon.
The AF sensors won't light for manual focus confirmation. Bonne chance!
I have no idea if auto exposure works properly on Canon. I doubt it; Canon's
cameras really need to talk to the lens to get consistent results.
This lens will be about as much fun on Canon as a Ukrainian 16mm fisheye,
meaning mostly for contortionists.
On Sony and Minolta Maxxum AF top
The diaphragm is manual on these cameras. This means that you have to turn
the aperture ring to 3.5 to focus, and back to f/8 or whatever to shoot.
Since you focus by scale rather than through the lens, this means you can
leave it set to your shooting aperture and simply suffer a dark finder image.
There is some gobbledygook in the manual about how to deal with the "release
lock," whatever that may be.
The instructions list specifics for many models of Minolta and Sony cameras,
but only with foreign model names and numbers.
Pro-Optic 8mm f/3.5. enlarge.
Specifications top
Intro Specs Performance Compared Recommendations
Optics
Diagram. bigger.
10 elements in 7 groups.
Something is aspherical, probably the magenta blob above.
Multicoated.
Angle of View top
Film and FX: slightly over 180.º
DX: 180.º
1.6x (Canon): 167.º
Close Focus top
1 foot (0.3m) from the image plane (the back of the camera).
Hard Infinity Focus Stop? top
Yes.
Too bad the factory doesn't calibrate it: I got best infinity focus set to 1
.5 feet.
Focus Scale top
Yes.
Depth-of-Field Scale top
No.
Infra-Red Focus Index top
No.
Diaphragm top
Pro-Optic 8mm fisheye set to f/5.6. enlarge.
6 straight blades.
Stops down to f/22.
Aperture Ring top
Yes.
Plastic.
Annoying arbitrary half and full-stop clicks.
Nikon version has no click at f/4, just f/3.5 and then f/5.6.
Filter Thread top
None.
Size (specified) top
75mm diameter.
Lengths, extension from flange:
Nikon: 74.8mm.
Canon: 77.3mm.
Minolta AF/Maxxum/Sony: 76.8mm.
Pentax: 75.8mm.
Weight top
13.800 oz. (391.3g), measured naked.
With caps: 14.815 oz. (420.0g).
Rated:
Nikon: 417g.
Canon: 443g.
Minolta AF/Maxxum/Sony: 424g.
Pentax: 414g.
Hood top
None, just the solid plastic things that poke out mostly to protect the lens
from physical damage.
There is so little flare that it doesn't matter.
Caps top
8/3.5 with caps. enlarge.
The front cap is plastic. It clamps over the petals, grabbing them from the
inside with two spring catches.
This is nowhere near as nice as a solid-metal, felt-lined cap, but it's what
you get today.
It's exactly like the cap that comes with the $2,100 Canon 14mm f/2.8 L II.
It comes with a rear cap for the appropriate mount; I've shown it here with
a real Nikon cap.
Case top
Fuzzy black velvet cloth drawstring pouch, included.
Made in top
Korea, the home of all those child geniuses with IQs of 232.
Warranty top
1 year, USA.
Packaging top
Single-wall cardboard box.
Glossy halftone graphics on exterior.
Dull white-coated box interior.
White plastic lens holder inside; similar to the molded plastic that holds
candies inside boxes of candy.
Pouch and instructions sit on top of plastic lens holder in box; lens sits
inside in a plastic bag.
Introduced top
December 2009.
Performance top
Intro Specs Performance Compared Recommendations
Overall Focus Ergonomics Falloff Filters Ghosts
Color Fringes Mechanics Projection Sharpness Sunstars
Overall back to Performance back to top
The 8mm f/3.5 works GREAT!
At f/5.6 and smaller the image is super-sharp.
I love the projection; it's less distorted than other fisheyes.
Focus back to Performance back to top
Manual focus is much nicer than expected. It's smooth enough to glide with
one fingertip.
Forget trying to focus through the finder. Depth of field is so great that
the most effective way to focus is to guess the distance, set it on the lens
, and then leave it alone.
My sample had a manufacturing defect where I got the best infinity focus
when set to 1.4 feet. There is so much depth of field that you'd probably
never notice.
This made it easy to use: I set it to 1 foot (0.3m) and never touched it
again.
Ergonomics back to Performance back to top
Pro-Optic 8mm f/3.5. enlarge.
Ergonomics are the same as any other manual-focus Nikon AI-s lens.
Ergonomics are great: just shoot. Nothing gets in your way, and the aperture
and focus rings are always where you need them.
My worst whine is that the aperture ring has inappropriate half-stop clicks
between f/5.6 and f/16, confusing real Nikon shooters who expect full-stop
clicks. Likewise, the f/4 click is missing, but I can figure it out, and it
indicates properly in the finders of better Nikon cameras like the D300, in
spite of the lack of a click.
Falloff (darkened corners) back to performance back to top
Falloff is negligible.
There is a tiny bit in the very farthest corner of DX at f/3.5, and it's
gone at f/5.6.
I doubt this would even be visible on 1.6x cameras.
Filters, use with back to Performance back to top
Forget it: there is no provision for a rear filter.
You could tape a gel over the small rear element if you insist.
Ghosts back to Performance back to top
Ghosting is negligible. Most people might prefer more!
Ghosts, typical. Disk of Sun in upper right. (f/11, D300). bigger.
I can't get ghosts, even with the sun in the image.
If I really try, and set everything up so that I do get a blob right where I
can see it, this is the worst I can do. The sun is in the image in the
middle of the white area.
Ghost, worst case. (f/16, D300). bigger.
Lateral Color Fringes back to Performance back to top
There are no lateral color fringes on the D300 or D3, which corrects for
them automatically.
On the D40, which can't correct these, there are some green-magenta lateral
color fringes, but much less than with Nikon's own 10.5mm f/2.8!
Mechanics back to Performance back to top
Rear, Pro-Optic 8mm f/3.5. enlarge.
The 8mm f/3.5 is built better than I expected. It's tough, solid and precise
.
Hood Flaps: Tough plastic; 2mm thick.
Focus Ring: Metal, rubber covered. Engraved markings
Barrel: Metal, painted markings.
Focus Helicoids: Feel great: smooth and silky with no play.
Aperture Ring: Plastic; painted markings.
Mount: Some sort of slightly warm-toned metal.
Serial Number: None found.
Ass-Gasket (dust seal at mount): No.
Noises When Shaken: Almost none; this is one of the quietist lenses I've
ever shaken.
Made in: Korea.
Projection back to Performance back to top
Projection is where objects are rendered in an image, or how a lens "
projects" each subject onto the film. For example, I share Nikon's
projection data for its 8mm lens in its review.
In a perfect fisheye, the distance of an object away from the center of the
image, measured in millimeters, is directly related to the distance of the
subject from the center, measured in degrees.
In a perfect fisheye, if you have things spaced 10º from each other,
they'll stay equally spaced in the image.
If you're looking at a brick wall, bricks in the middle subtend a greater
angle in degrees than the bricks at the sides, which you're seeing at an
angle. Fisheyes are supposed to give curvy looks to things and make objects
on the sides look smaller, but not if they occupy the same angle.
If you photograph a bunch of spheres arranged in a circle around you, your
image should show a bunch of equal-sized circles with a fisheye.
If you photograph a line of spheres in a line, say outdoor lighting, then
the circles in your image should get smaller towards the sides, but remain
circles and not get squished into ovals.
Most fisheye lenses cheat, and push objects closer together at the edges of
the image. I find this makes the edges fairly useless, since everything gets
so squashed.
This Pro-Optic lens does a much better job of keeping things from getting
too small at the periphery than the Nikons. In fact, this Pro-Optic lens
does the best job of any fisheye at keeping balls round at the sides of the
image. It's about twice as good as the Nikon lenses.
This is why Nikon needs 10.5mm to cover the frame, while Pro-Optic uses 8mm.
This makes the center of the image smaller with the 8mm Pro-Optic (it
matches the center of the Nikon 8mm), but since the sides don't get so
squished, they fill out to the corners of the DX image with the Pro-Optic
8mm, but not the Nikon 8mm. The Nikon 8mm squeezes the sides so much that
instead of getting the entire DX frame filled, all you get with the Nikon
8mm is a circle in the middle with the top and bottom cut off (example below
).
Here now are two comparisons. Roll your mouse over to compare.
Roll over to compare to 8mm f/3.5.
Comparing the 8mm f/3.5 Pro-Optic to Nikon's 10.5mm, the center of the 10.
5mm is bloated, while its corners are squished.
Mousing-over to reveal the Pro-Optic lens, notice how it both shows a larger
overall angle, and squishes the corners much less! Look at the tiles in the
lower right: they are bigger and straighter in the Pro-Optic shot!
Roll over to compare to 8mm f/3.5.
The very center is identical between both 8mm lenses, as we'd expect.
The Nikon 8mm circular fisheye shows a larger angle by squashing-in the
corners.
The difference is that the Nikon lens squishes the sides too far, while the
Pro-Optic leaves them as they should be. If you had to crop the image from
the Nikon 8mm into a rectangle without black corners, it can't cover as much
as the Pro-Optic, because the Nikon pulls-in the black corners too much.
I kid you not: even as-shot, the Pro-Optic covers more than the Nikon 10.5mm
, and almost as much as the exotic Nikon 8mm that costs ten times as much,
and the Pro-Optic fits it all into a rectangle.
What I really love about the projection of the Pro-Optic is how the sides
and corners render the subject much larger than the other fisheyes. I find
this much more useful than squashing the sides into useless mush.
The Pro-Optic 8mm squashes the sides much less and is as sharp or sharper
there than the Nikon lenses.
If you use software to stretch it all back to flat, results from the Pro-
Optic lens should give much sharper results than Nikon lenses used this way.
Ha!
Sharpness back to Performance back to top
Warning 1: Image sharpness depends more on you than your lens.
Warning 2: Lens sharpness doesn't mean much to good photographers.
With those caveats, the 8mm f/3.5 is as sharp a lens as I've used, from f/5.
6.
Here's how it looks, hand-held at 1/8 second!:
Interior. (f/8, 1/8 sec., hand-held D300). original file (2.2MB).
Not only is this image sharp, and is it sharp hand-held at 1/8, the depth-of
-field is all-encompassing from a few inches to infinity.
Note also the tight contrast. Even with a window shining in, there are no
ghosts or veiling flare.
The excellent projection keeps the objects on the sides a useful size,
instead of squashing them into mush as does every other fisheye.
As seen on a 12MP D300:
At f/3.5 and f/4
There is a sharp core to the image, but contrast is lower from what looks
like spherical aberration. It's the same all over the image from center to
edge.
This is quite different from Nikon's own 8mm f/2.8, which at f/2.8 and f/4
is super-sharp in the center (better than this lens), but the Nikon is a
blurry mess in the periphery, much worse than this Pro-Optic.
At f/5.6
It's sharp and contrasty all over.
This Pro-Optic is much better than Nikon's 8/2.8, which is blurry on the
sides.
At f/8
It's the same as at f/5.6: excellent all over.
At f/11
It's the same as at f/5.6 and f/8: excellent all over.
I find f/11 optimum, since depth of field is always helpful since I never
bother to focus this lens.
At f/16 and f/22
Diffraction limits performance, so it's softer than f/5.6 ~ f/11.
Sunstars back to Performance back to top
With its straight 6-bladed diaphragm, the 8/3.5 makes 6-pointed sunstars on
bright points of light.
On digital cameras, these are usually hidden by a blown-out sky around the
sun unless you deliberately underexpose. You'll see them on bright
highlights, like reflections of the sun in chrome bumpers.
Compared top
Intro Specs Performance Compared Recommendations
Nikon 8mm f/2.8, Nikon 10.5mm f/2.8 and Pro-Optic 8mm f/3.5. enlarge.
Nikon 8mm f/2.8 Nikon 10.5mm f/2.8 Pro-Optic 8mm f/3.5
Weight 38.1 oz./1,081g 10.7 oz./303g 13.8 oz./391g
Front cap Screw-on billet aluminum with rubber bumper crappy plastic push-on
crappier plastic snap-over
Diameter 4.8"/123mm 2.5"/63mm 3"/75mm
Length 5.5"/139mm 2.5"/64mm 3"/75mm
Filters Internal turret Rear gel None
Use on FX? Yes Not really Not really
AF? No Yes, on better cameras No
Price $2,900 (used) $700 $290
Performance
I compared the Pro-Optic 8mm f/3.5 directly to the exotic Nikon 8mm f/2.8
and the common Nikon 10.5mm 2.8 G.
I've covered the large differences in projection above. I greatly prefer the
projection and look of this Pro-Optic lens; the Nikons make the periphery
too small, while objects seem optimally rendered throughout the entire frame
of the Pro-Optic lens.
I much prefer the look from the Pro-Optic lens because it doesn't squash the
sides beyond all recognition. It is a much less distorting fisheye.
If used on a Nikon Gen 1 camera like a D1X or a D40, the Pro-Optic lens has
much less lateral color fringes than the Nikon lenses.
In the center, both Nikons are sharp wide-open, while the Pro-Optic is soft.
Stop the Pro-Optic down a stop, and all three are as sharp as each other in
the center.
Wide-open on the periphery, the Nikon 10.5mm is the best. The Nikon 8mm is
horribly blurry, like a cheap motel door viewer. The Pro-Optic is as sharp
along its periphery as its center; the Pro-Optic's periphery is softer only
at f/3.5 and then much better than the Nikon 8mm.
Stopped down a stop, both the Pro-Optic and the Nikon 10.5mm are superb all
over, while the Nikon 8mm is still blurry along its periphery until you get
to f/11.
Recommendations top
Intro Specs Performance Compared Recommendations
This Pro-Optic 8mm f/3.5 is among the best fisheyes I've used. I especially
love it's much improved projection compared to other fisheyes, and from f/5.
6 and on, it's sharper and/or more free from lateral color fringes than
either the exotic Nikon 8mm f/2.8 or Nikon 10.5mm 2.8 G.
As a manual-focus only lens with almost unlimited depth-of-field, set it and
forget it.
My sample was out of adjustment, so best infinity focus was had by setting
it to 1.4 feet. Therefore, I set it to 1 foot and shot everything at f/11,
and everything was perfect.
A reader suggests that you may try to screw-up your focus yourself by
rolling back the focus ring rubber grip. Note 3 set-screws. Set the lens to
what is actually infinity focus. Unscrew these set-screws, rotate the focus
ring to infinity mark, tighten the set-screws. The lens should now focus at
infinity when set to infinity. GOod luck; I haven't tried this.
I've bought a lot of fisheyes over thirty years, starting with a screw-on
converter, then the Minolta MD 16mm in the 1970s, and eventually Nikon's AF
and manual-focus 16mm fisheyes.
There really isn't anything useful you can do with a fisheye, other than use
the images as a basis for tweaking back to straight with software.
If you're going to buy a fisheye, it doesn't make much sense to spend much
money on it, since you'll probably get tired of it in a few days.
Everything points to getting this lens over the Nikon or Canon lenses. Heck,
Canon doesn't even make a fisheye for its small-sensor cameras.
This Pro-Optic lens is optically excellent, and works great, at least on
better Nikon bodies. I'd be careful on Canon or other brands, where it will
be less compatible. No problem; Adorama usually offers a complete money-back
refund if you don't like it, and return it unaltered.
If I wanted another fisheye, I'd get this instead of the Nikon 10.5mm for a
DX camera. I prefer its projection.
Help me help you top
I support my growing family through this website, as crazy as it might seem.
If you find this as helpful as a book you might have had to buy or a
workshop you may have had to take, feel free to help me continue helping
everyone.
If you've gotten your gear through one of my links or helped otherwise, you'
re family. It's great people like you who allow me to keep adding to this
site full-time. Thanks!
If you haven't helped yet, please do, and consider helping me with a gift of
$5.00.
The biggest help is to use these links to Adorama, Amazon, B&H, Calumet,
Ritz, J&R and eBay when you get your goodies. It costs you nothing and is a
huge help to me. eBay is always a gamble, but all the other places have the
best prices and service, which is why I've used them since before this
website existed. I recommend them all personally.
Thanks for reading!
Ken
Home Donate New Search Gallery How-To Books Links Workshops
About Contact | M******3
发帖数: 1173 | |
|
