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01/06/2006 03:26:03 PM · #1 |
Do the new 'optimised for digital' lenses actually give better picture quality than the previous 'standard' lenses?
I understand that they are designed to project on to the smaller size sensors in some cases (ie Nikon lenses) but is there anything else and do they have any discernable impact on picture quality.
I'm asking because I'm looking to buy a top quality Nikon zoom and I'm not yet convincced that the new optimised for digital 17-55mm f2.8 gives as good a picture quality as the previous lenses (17-35mm f2.8 or 28-70mm f2.8)
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01/06/2006 03:46:57 PM · #2 |
There maybe two things you may have heard.
First, for camera like the D100 that thave APS-C sized sensors, they have lenses that have a smaller rear element. This mainly results in smaller and lighter lenses. They will vingette if you put it on a camera with a full sized sensor.
Second, some lenses are coming up with coating made specifically for dSLR sensor, since they are more reflective than films. They are said to reduce CA, ghosting/flaring. My personal feeling is that they do work.
Sigma's have DG to denote Digtal Coating and DC to denote smaller size for cropped sensor, Tamron has Di to denote Digital coating with Dii which has the coating and a smaller rear element for cropped sensors. If I remember correctly, Nikon uses DX for use in cropped sensors but I don't know if they have a coating specific for dSLR's.
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01/06/2006 03:54:32 PM · #3 |
"Optimized" does not necessarily mean a good thing quality-wise.
As Yido mentioned, (the DC portion, not the DG portion), the lens is optimized to produce a good image in the central area of the lens. It is therefore cheaper (or should be) than the equivalent full-frame lens.
If you do not plan on upgrading to the full-frame camera (Nikon does not have one yet?) then you should be fine with it.
-Serge |
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01/06/2006 04:54:20 PM · #4 |
A lot of it has to do with specific coatings, etc. for the reduction of chromatic abherrations when using lenses on digital SLRs.
I imagine we will likely reach a point in the near future where it will be moot. ALL lenses will have the digital optimizations. |
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01/06/2006 05:54:02 PM · #5 |
Originally posted by theSaj:
A lot of it has to do with specific coatings, etc. for the reduction of chromatic abherrations when using lenses on digital SLRs.
I imagine we will likely reach a point in the near future where it will be moot. ALL lenses will have the digital optimizations. |
No, that's not the main point with this lens he is asking about. In fact, the lens projects a smaller image circle, designed to work specifically with Nikon's "cropped" sensors.
Anyway, to respond to the original poster, the Nikon shooters at Fred Miranda consider this to be Nikon's best zoom. They rave about its sharpness and its build quality.
R. |
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01/06/2006 06:23:52 PM · #6 |
I think digitally optimized, in Nikon's case, is all about DX.
If you read a bit you will discover that 17-55mm is as good as the other two 'legends' you have mentioned.
If you keep on reading, you will also notice some people having a problem with the motor of 17-55mm. I was doing some research a while ago and read a few posts that mentioned the motor getting really loud and not being able to track moving objects when it happens.
People who tested the same process after reading the initial post reported the same problem. I don't know if they all had bad copies, but if that's the case, then there would be a lot of bad copies around. |
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01/07/2006 12:24:48 AM · #7 |
Well, I don't think the rear element being smaller for cropped sensors neither helps nor hurts optics, if that's the question. Gotta look at each design on it's own. I don't think you can say all DX lenses are better or worse based solely on the size of the rear element.
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01/07/2006 01:13:05 AM · #8 |
Lenses designed for use with 35mm should not be as good for digital sensors, even when used with a full frame sensor, as the light towards the edges and corners hit the sensor at an angle, reducing light that reaches deep within the pixel well, and may also cause vignetting.
A made for digital lense should hit the sensor perpendicularly straight on so there should be no loss of light at the corners and edges. The reason the legacy lenses (made for 35mm film) performs well on a cropped digital sensor is that the light hits it at the lense's sweet spot, where you get the best image quality.
A legacy lens used on a full frame digital sensor has to have some degradation at the edges and corners, unless you are using the very best, most expensive lenses available. This may not be so noticeable depending on the focal length used and since full frame sensors have very a narrow DOF. |
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02/08/2006 05:30:07 AM · #9 |
I'm also musing on this topic after recently buying an EOS 350D. I want to get a macro lens, but Canon are reticent to release anything other than a 60mm macro in EF-S form.
The one thing I can't find is an actual comparison between digital and non-digital lenses on a digital body. Ignoring for now the discussion over whether to get Canon or Sigma or Tamron macros, is there a specific, demonstrable advantage to having an EF-S lens over an EF?
I've also heard the various statements as echoed by Olyuzi, but have yet to find any evidence of these. Is it overplayed for marketing purposes?
I'll keep hunting, and add any new info if I find it. |
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02/08/2006 05:58:01 AM · #10 |
| I'm probably wrong, but I thought EF-S lenses were cheaper to produce because of the rear lense being further back in the camera. Certainly when you look at the prices EF-S's are cheaper than EF's. |
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02/08/2006 06:05:54 AM · #11 |
I think technically they are since they use less glass and all, but the difference is minimal. I think Canon keeps all the saving for their profits though. It's also a nice way for them to create a new market for lenses.
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