Though my optical design knowledge is rudimentary, but looking at the two designs above, they would have different light collecting properties.
The middle element in the Sigma design is thicker. Unless Sigma decided to use ED or Super ED glass, the refraction of that lens will be significantly larger, and light traveling pattern after that would be different. The front element of Sigma's is over-engineered compared with m.Zuiko's. Don't know how much those etches around the edge of m.Zuiko lenses would affect the optical quality.
So yes, different proportion of element's size and glass used will change the final IQ. They're still of the similar design, but IQs would be different. And production costs would be very different due to whether ED elements are used or not (and Olympus's production technology is higher than Sigmas's).
citizenlouie: Most lenses are based on Zeiss formulas, so it's not surprising many lenses designs are similar (but not identical, because that would patent fringing). This is especially true for telephoto lenses (not super telephoto) where elements are smaller in number.
Actually that's not true, dbateman.... I remember reading a little history about that. Nikon became a well-known brand in the U.S. because many soldiers brought back Nikon products from WWII. The story was about a soldier first discovered Nikon because he went on board of a Japanese submarine and noticed how bright the scope for looking at the surface (whatever that is called) is. And it was designed by Nihon Kogaku (now Nikon). I am pretty sure they designed the lens before Japan surrendered.
Same for Olympus. From OM Lens manual, Olympus said many of their 35mm ambitions were destroyed during the war, so they had to restart 35mm camera designs from ground up. But before that, they had a lot of good blue prints already.
@Marty Because many people dwell on their laurels. So a little hardship is actually good motivation for innovations. Once a person thinks he's the king of the hill, he has no motivation to become better. Romans fell the same way.
Here, lens design diagrams. As you can see, many lenses from different manufacturers use similar designs, just different element sizes or switch around certain elements from the basic design, but most of them are stemmed from Zeiss designs. http://taunusreiter.de/Cameras/Biotar_en.html
Before CAD, design your own lens from ground up without following Zeiss formula is just too difficult. Now with CAD, even zoom lenses can be designed with high quality. And Olympus is the pioneer of using CAD for optical designs.
Ferling: Third party OEM is nothing new, so long as they have the tools and talent to meet the clients specs and stick to them. Who cares what the origination address is?
In my search for vintage lenses, I remember an article (for which I can't find the link), that the majority of early Japanese lens manufacturers were all based a stones throw from one another, and consequently, copied each other.
In the 80's Sear's had a few good lenses made by Tokina, and it requires some research to know which ones were gems hiding under the name. Vivitar was well known for utilizing many different OEMs for their lens designs. There were several different OEM's for a given lens (i.e. 4 different 70-200 series 1), and their serial numbers were all telling of those of whom made them, (Tokina, Komine and Kino are regarded as the worthy versions).
It all basically boils down to a great design, supported by a vendor with solid capability. Sigma sells some very decent lenses, so it's no surprise.
The Sears/JC Penny/Vivitar don't make their own lenses, so they contract OEM makers and rebrand lenses. That's a very different business model than manufacturing lenses using other people's lens formula.
It's true most early Japanese lenses makers were copying each other's lenses. Olympus, wasn't one of them. Olympus was and still is a microscope company, and their "original" intention to make camera lenses was to create some lenses for their microscopic division, so they had the incentive to create lenses in house from ground-up. Many OM lenses are not copying or a modified version of Zeiss formula, which was not the norm at the time. OM 135mm f/2.8 is one of those original designs. I think the legendary OM 50mm f/2 is also another fine example.
I've used Sigma 19mm f/2.8 for m4/3 though.... RAW performance (i.e., non-software corrected performance) is not impressive. Contrast is very low, CA is very high, but geometric distortion control was good.
Joseph S Wisniewski: Makes a lot of sense to me. The thing I don't get is why Oly?
75mm is a bit of an odd duck on four thirds, 3.5x the "normal" focal length for four thirds (a 150mm equivalent). The classic portrait lenses are 85, 105, and 135mm, 2x, 2.5x, and 3x normal.
75mm is the portrait lens that everyone wants on APS-C, where it's 2.5x normal, but quite awkward on four thirds.
150mm equiv makes sense on 4/3 format. I have one. You have to remember 4/3 sensors have squarish aspect ratio, so the extra reach actually makes up to feel like a 135mm, and I love that FL.
And your 2.5x normal and 3.5x normal doesn't make sense to me. 135mm and beyond is telephoto. Telephoto has a very different feel to them (compression). It has nothing to do with how many times of "normal" focal length (which is actually 43mm).
yabokkie: I'm also (and more) interested in 12-60/2.8-4 for the SLR 4/3". Oly didn't have much know-how of modern lens design but this lens was very different.
Olympus was the first company to use computer aid design to make lenses..., when all other companies were still using trial-and-error method back in the 80's.... Not knowing how to make modern lenses? Enough said.
Most lenses are based on Zeiss formulas, so it's not surprising many lenses designs are similar (but not identical, because that would patent fringing). This is especially true for telephoto lenses (not super telephoto) where elements are smaller in number.
citizenlouie: These are the killers.... Very good move, Pentax. But what I don't understand is why Canon Red on Pentax lenses.... What happened to green?
I think it makes more marketing sense if big players stick with their distinctive color so when people spot the lens, they know which brand it is.
Canon = RedNikon = YellowOlympus = BluePentax = Green
These colors are very established, if Pentax changed it, that means it now has to start from ground zero to rebuild its brand recognition.
These are the killers.... Very good move, Pentax. But what I don't understand is why Canon Red on Pentax lenses.... What happened to green?
I feel the pain for web masters. The idea is wading through constructive criticisms and destructive criticism. Censorship isn't a solution, because censorship really turns people off, sometimes creative people with genuine ideas. Spams have no place whatsoever, however.
mckracken88: not convinced.
not a fan of overdone hdr and filters. (and foam water)
It's not HDR. It's exactly what you get if you shot in overcast, gloomy lighting, you exposed right. No HDR required to get the color.
Mr Fartleberry: I learned a long time ago not to waste my time and film on these sort of shots. Even today very few RAWs from trips get processed afterwards shooting in cloudy/rain conditions. I use my time better running into town and getting a real meal.
Then again maybe you can buy those zillion bags and rain covers thru Amazon if you think someone wants to buy your pictures of occluded misery.
Perhaps you exposed them improperly. Under cloudy/overcast days, you can get very saturated color in your photos without photoshop. I think use a slide film probably works better under such lighting.
Benarm: Interesting, but many of them look staged.
Yes, they're staged, like graybalanced explained already. And I'm going to add a little art history here. In the beginning of photography, it's considered as an inferior art form than painting, so many photographs were mimicking paintings in term of aestheticism. The trend of "straight photography," that is, shoot photos as photos, instead as a subjugate form of painting is a relatively modern notion (IIRC, it was under people like Edward Weston and Stieglitz who made people realized photography is a separate art form).
Isn't it ironic that pioneers of photography took so many decades to establish the photography as a legitimate art form only to be reduced by people who shoots rubbishes due to the wide availability of easy-to-use cameras and smart phones?
The purpose of art is to promote thinking. If even the artist himself doesn't think when he creates, what kind of art could you expect?
The simplest way to appreciate arts is to take an art class, and put your own hands on the project from beginning to finish. Some of people here who don't appreciate them because they've taken things for granted by their easy-to-use DSLRs. Once they understand the whole film taking/develop process, they'll know even the smallest things like metering, focusing, selecting the direction of light, select correct focal length to use (e.g., something like do you want to use a 50mm and stand 3 feet away from the subject or a 75mm and stand 6 feet away), and choosing the correct films for correct lighting/effect are distinctions between a skilled photographer and an unskilled one. Some immature people just like to put down other people's effort in order to hide their inner insecurity or lack of aptitude to learn.
clicstudio: Gorgeous and amazing photos! They almost look recent.Makes u realize the "real" photographers were those, 70 to 80 years ago, who shot manual and film and without an LCD screen to help and no photoshop.I really admire them and the glimpse of Americana their photos show. Color makes the whole difference. Thanx for sharing!
@ Scott Easton
Yes, some of the older photographers, if were given a new DSLR of today, would definitely use the newer format. But they won't use it as a point and shoot and hoping one shot would come out right. Beautiful photos like these were not achieved by coincidence, because you need to know your lighting theories inside out. Back then, because of the limitation of their equipments, pro photographers were actually considered skilled workers.
Hobbit13: These (amazing) photos have been online for ages (Wikipedia uses them in many articles). So what's the "news"?
I'm still deeply impressed by the image quality of the "Turret lathe operator ", even for today's standards, that's a very high resolution picture. see full image at:http://upload.wikimedia.org/wikipedia/commons/1/1a/WomanFactory1940s.jpg (uploaded in 2005!)
Ansel Adams is known for his painstakingly made post-processing skill. Back in the days, post-processing was done in dark room, not Lightroom. That's the only difference. However, when he shot them, he already knew what he was going to do in dark room, how to crop, how to meter so the photo would be underexposed/overexposed to save highlight/shadow detail. Post-processing, is as old as photography itself. Though some of us are minimalists, but I don't deny the usefulness of PP, especially when your medium has limitation. I find it repulsive only when it's abused. An experienced photographer should integrate PP (if needed) as part of the process, rather than as a fix of a badly shot photo.
Good new test method! I like it. I see no surprise with the test result though. RX100 II's IQ is the worst, the other three cameras shows similar results, with NEX 6 slightly better at base ISO. Olympus shows best color (no surprise), but the big surprise here is Panasonic's JPEG engine has improved to be fairly acceptable now. Great achievement.
peevee1: Correction data for a lens should be stored in a lens. Every lens has some NVRAM anyway (so body can read its identifier). Nikon and Canon got the protocol wrong.
@Just a Photographer. Nikon can do it like what Olympus does. Hook the lens to the camera body and run the update program. Both my 4/3 and m4/3 cameras/lenses are updated the same way. I think the reason Nikon does it this way though is because there are many legacy lenses in their library, whereas 4/3 and m4/3 are made for digital format from ground up (and distortion data was already embedded in the lens when they released). So what Nikon did was the only feasible way.
Just use common sense when reading reviews. If the review contains a lot of hyperboles and lack of objectivity, then I usually discount it more than the one that's more impartial and honest. Another thing I find is, some people are so happy about their purchase, which is nice they rave about their purchase, but please let us know what's the reference point. For example, some people say "it's the sharpest lens I have ever used." Which is nice, but how many lenses you have used is a very important criteria when people judge the quality of your review. Same can be said about negative reviews. I don't know if they're still teaching this in college, but when we do research (reading reviews is kind of like a purchase research), we need to know the credential of the person who wrote the article. An industry expert's words weigh more than someone who's merely very enthusiastic about the subject.
Well deserved first place. Not only the subject is nice, but the attention to the backdrop is just excellent with meaningful use of shallow DoF. Amour means "love" in Spanish, and the other word in focus is rapport. Both show what a marriage should mean.