Great glass, horrible focus mechanism.
937208
Okay, I was super skeptical of this lens before purchase and took a chance because of price. I have been pleasantly surprised by the quality of photos taken with it and dare say the glass is as good as the Canon brand 50mm. However, the focus motor and whatever gear system inside this thing are absolutely terrible. It's super slow, loud, and I can hear the poor under powered motor struggling to move what might be a system of unlubricated gears during focus. I point this lens down or straight up, sometimes the motor can't even move the glass at all. It has to be somewhat parallel to the ground to operate well for what it is. 3 stars because the photos are so dang good and manual focus works great. If you're on a budget this thing is perfect. If not just get the Canon one
2821877
If it wasn't for the focus problem this would be a great camera for the price. The image gets really blurry when the camera is zoomed out (1X/2X zoom).  When zoomed in (3X) the image is great. Until the focus problem is fixed stay away from this one - I'm returning mine.
2390553
I researched this quite a bit before I ordered it and everybody raved about the optics but hated the focuser and complained of nicked or scratched tubes.
When I recieved mine the scope itself was immaculate - still an extremely ugly scope but it was not beat up - the focuser on mine works fine with no troubles but that is where the good news ended.
The supplied 2 inch diagonal mirror was broken - the mirror is held in place by a cheap , thin plastic ring that is so brittle if you look at it wrong it breaks - there is absolutely no way this would hold collimation or stay  collimated for long.
Also, the optics on the one I recieved are no better than my ST80 as far as quality or sharpness of the image is concerned. I tried several diagonals , 2" , 1 1/4", prism and mirrors but to no avail.
Star testing showed that any brighter stars will not focus to a pinpoint - they all have terrible flares - in focus and out focus images show horrible optics or alignment - since this is a triplet it is almost impossible for the average person to collimate it.
If you are looking for a relatively less expensive short tube get a Williams Optics or Astro Tech - for $100 more you can have a real  telescope. Triplet or not this telescope is a no-go.
930058
The Canon EF 28mm f/1.8 lens focuses quickly and accurately, and can produce nice pictures as long as you keep your subjects away from the edges of the frame. The center is sharp, but even on an APS-C (cropped frame) camera such as a Digital Rebel or 50D, the edges are quite soft at f/1.8 and remain noticeably soft no matter how far you stop it down. On a full-frame camera such as the 5D Mark II, the edges are unspeakably bad. The lens also shows strong chromatic aberrations and heavy purple fringing around specular highlights. Stopping down does not reduce these effects significantly, but it is usually not a problem on indoor shots as long as sunny windows and unshaded lamps (including flourescent tubes) are kept out of the frame.

My goal in purchasing this lens was to improve my indoor martial arts photography, but its optical defects were so frustrating that I found myself taking any excuse not to use it. I simply couldn't trust it to produce usable images. I ended up selling it. Now when I need a fast lens in about this focal length, I usually reach for the less-expensive but optically superior&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/Canon-EF-35mm-f-2-Wide-Angle-Lens/dp/B00009XVCU/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Canon EF 35mm f/2 Wide Angle Lens</a>. The 35mm f/2 does not have USM, so it does not focus quite as quickly or silently as the 28mm f/1.8, but it produces good pictures without weird color artifacts.

The EF 28mm f/1.8 USM is the worst prime SLR lens in Canon's product line as far as I know. It is the only such lens that I recommend avoiding.
1490617
I had this lens on a camera last year. It performed pretty good. It was pretty fast and good in low light. Good build, Auto-focus was pretty good and overall i was happy. It quickly became my everyday walk-around lens.
So, when i upgraded my camera body (7D MII), i ordered another one as it is several hundred dollars cheaper than the Canon L version. However, i clearly got a lemon. The auto-focus would work for a couple of minutes and then would just make a grinding noise and would not focus on anything.
So, i returned it and went with the Canon L glass.
3924157
I'm a full-time professional photographer with 30 years experience. I added videography about four years ago and have been creating advertising material for clients in the beauty industry. I bought this Canon 85 to record a series of interviews with celebrity hair stylists. I tested the lens at home and found that it was not sharp wide open at f1.8, mediocre at f2.8, and good at f4. So I shot all my interviews at f4. I'm sad that I can't use it at 2.8, like the rest of my other Canon lenses. However the rest of my Canon lenses are all "L's", with the exception of my 50mm f1.4 - which is one of the finest lenses I have ever owned.

Robert Marcos
496817
Great except for the focusing ring. There is way to much play in it.
377134
After laughing about the absurd looking device I adjusted it to my face, nose and eyes and gave it a try. Its obvious that you cant focus both of the eyepieces toward a single object 3 inches from your face, (that's the focal length for such a powerful eyepiece). Simply roll one of the eyepieces up out of the way for viewing your work space for reference and use the device for very close viewing of small features. The eyejpiecescan be removed and you have two single very strong viewers.
874077
I have been using this lens for about a month, so I think that I have a good feel for it.

PROS
1- It has one of the best optical stabilization systems that I have ever used.

2 - Its range of 18mm-200mm is amazing.

3 - It feels firm and solidly built.

4 - It produces crisp and sharp pictures when the light is good.

CONS
1- The control ring is strictly "by wire" and does not inherently control anything.  Therefore it forces you to go into the camera's god-awful menus and submenus before you can manually control anything.  I found this to be so much of a pain that when I want to slip into a manual operation I find it easier to simply remove the Sony lens and put on a third party manual lens.

2 - It is very slow.  It does not work well in low light conditions.

BOTTOM LINE
You should definitely have this in your kit.  But do not expect it to do everything that you want.  Make sure you have a few good, fast, manual prime lenses to cover the situations where this will fail.

Peace

David Courtney
2604405
After reading the absolutely wonderful reviews across most of Gunnar's products, I decided to give these a shot.  I chose these specific glasses because unlike the rest of the Gunnar lineup, the lenses on these didn't have the yellow tint which would have made it a deal breaker as I need color accuracy in my work.

First, the overall finish on these is honestly subpar at best.  The frame feels like something that you would expect to find on glasses costing a quarter of what these cost.

Second, the lenses are absolutely horrendous fingerprint magnets! I can't even begin to describe just how bad it got.  But just to put into perspective.  I wash my hands, I wash my face, no oil anywhere, everything is clean.  I put the glasses on, and within 15 minutes I have to take them off to get rid of a smear from either my eyelashes touching them, or an eyebrow hair falling past them.  I honestly spent more time cleaning these than wearing them.

But maybe even all that I could tolerate... What ended up being the absolute deal breaker for me and what caused me to return these was that I use 2 displays.  A 27" iMac, with an older 20" display next to it.

When I tried using these while using a small laptop screen, I did notice they do somewhat help.  When I tried them while sitting in front of my usual setup, the 27" iMac screen was scaled up so much that I felt like I was sitting too close to the screen in a theater.  The second screen, which stands next to the 27" one, not only kept on making the exposed edges of the lenses give off a weird glare into my eyes.

On top of that, what you need to understand is that these are good only for staring into one point without moving at all.  If you're used to using multiple screens you know it's easier to just move your eyeballs instead of your whole head.  While wearing these if I just looked at the second screen without moving my entire head I was always ending up looking past over the bridge of my nose in the tiny gap left by the frame - and since one eye is looking though a lens and the other isn't, that alone gave me a horrible headache.

And to top it all off, my work requires plenty of jumping between the screen and paper - ie look at the screen, look at a notebook on the table.  Again going back to just moving my eyes, I kept on glancing under the glasses which resulted in my eyes having to refocus much more than they would have otherwise, again giving me a headache.

So to summarize, if your work includes sitting for 8 hours inputting numbers into a spreadsheet without looking away from your screen, and as long as the screen is no more than 20" away, and if it's your only screen, then these may help you.  If you work with big and multiple screens and do something other than just staring at your screen without even glancing to the side for a second, then I really really would not be able to recommend these.  Shame, was honestly expecting more of these...
3497195
It a nice lens. It's very sharp and the craftsmanship is solid. Feels great to use. If it were priced at 500 dollars it would be a great lens.

There is a flaw with this lens when used with video. The specs claim it's a constant 2.8 aperture.. and this is true and works for still photography. However when you use this lens for video and zoom with it on a subject, there is a flicker that is apparently caused by the aperture readjusting as you zoom. I would not recommend using this lens for video use.
4143991
When I first started shooting video and photos with this lens it truly made me believe that the quality of glass will make or break your captured moments. My clients and future clients have been truly amazed by the shots I've captured with this lens. Although their is one drawback I noticed and it maybe just the copy that I received. The problem I noticed is with the auto focus. When in video mode or photo the lens has a hard time focusing in on subjects closeby. The problem is apparent even if their is bright light and the shutter us pressed half way. I missed so many important moments because of this. Having one or 2 blurry shots of the same scene or moment being captured is pretty acceptable but not 6 or 7 of them in a row.  It's like the lens gives up and doesn't want to focus anymore. I'm wondering how the 5 star reviewers are posting that the auto focus is great? Maybe they just haven't had time to come back and update. Don't get me wrong I LOVE THIS LENS but looks like I may have to return it if the exchanged one coming my way soon does the same exact thing.  By the way I have a gh2 and gh3 both have the 14mm and 12-35mm and they focus much faster. I even double made sure the AF switch wasn't being switched to manual by accident as well as on the camera body. I stay away from the 23 area focus and stick with only single point or one area. I shoot with manual focus as well but sometimes I need to be in AF mode. But for now it looks like the lens wants to go against focusing instead of going with it and just cooperating. This is a really frustrating experience with this lens especially when I start to realize the steep price I paid and the AF has a mind of its own.
3142465
This lens is extremely sharp and been my main lens for over a year now. However, upon receiving focus was way off. I had to purchase separate sigma dock to make adjustments. It took me almost a week to get focus corrected. Lens was way off. Out of the box it was unusable. 3 stars for that. For almost $1000 it shouldnt be having such a poor quality.
246227
I love everything about the glasses except for the lenses. They produce a glare which make them inadequate for driving. I would gladly pay three times as much if it had better lenses.
3242823
I have a Vortex...but this thing defies all logic about chiness made scopes. The glass is so clear...up in par with Vortex if not better than the lower models.  This thing is amazingly Sharp. I will test out the zero holding and the tracking, but so far it looks very good. Installing on a DMR 20" wydle AR 15- shooting 75GR , 500 Yards.

However, it is not a 40MOA scope on the elevation. The complete travel on it is barely 33MOA  and after you zero in, you won't be able to adjust past 23MOA...that means  this scope us useless it you want to shoot past 700 yards.  THIS SUCKS and the description is very misleading.
3906993
The riflescope has a wonderful visual quality, looks great mounted on my long gun. I notice the following issues with the functionality: the level bubble is very slow to react and you cannot rely on it for a fast set up. The right / left turret is very sloppy to adjust and when locked it still is able to operate a few MOA. Finally, the clairity at long range sighting it not very good. Even with carefully trying to adjust the focus and parallax I still could not get a clear sight picture until the power was reduced to around 20X.
2077404
First of all, I know that if you're interested in this lens you'll end up buying it anyway cause it has raving reviews anywhere you look and it's cheap.

Anyways, I wanna give my 2c about it because I don't agree with much that I've read here.

I'm using it with a brand new Canon T2I that takes amazing pictures with the kit lens (18-55mm). I bought this lens hoping to take some nice portraits and for it's ability to blur nicely the background, since it has a very wide aperture (f 1.8).

I can say that at least 70% of my pictures are off focus. I'm using single manual focus point in the t2i (center point) and even tough I always focus on my subject's eyes, their entire face seems WAY off focus in 70% of my shots. This doesn't happen at all with the kit lens. I don't know if I got a defective unit, it doesnt seem to be the case, but that's just the way it is.

People say it's not sharp at 1.8 and they are NOT kidding. Its really, really, really soft. For the pictures to be usable I have to use at least 2.8, wider than this you get a very soft picture. And I'm not even a pro, they're really unusable.

It does have a nice ability to blur the background, but FORGET about taking any landscapes shots with this glass, because 50mm on a t2i or similar is very "zoomed in" if you know that I mean ...

If you just bought a DSLR and its your first lens after your kit lens, PLEASE keep in mind that this is a FIXED focal lenght lens, wich means it doesnt zoom in or out like your kit lens (wich goes from 18 to 55 mm). AND remember that on cropped bodies like the T2i, T1I, etc, you have to multiply the focal lenght by 1.6, so this actually means you're buying a 80mm mens. In my experience it's VERY hard to take indoor pictures with this lens because it always seem it's "zommed in" ...

If you really wanna know how it behaves, get your kit lens, zoom it to 50mm and pretend you can't zoom out. Try to take pictures with it for a day like that and see if you find your shots usable ...