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Old Jun 7, 2011, 1:18 AM   #1
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Question Lenses + adapters

Just got a good deal for a NEX-3 camera with the 18-55mm lenses. I am not a Sony fan but I really liked the high ISO performance of the camera so I thought it would be a good replacement for my Canon S5 IS P&S camera...

Now I have a few questions with lenses. As far as I have read, the focal length equivalence is still 1.5x as with most DSLRs. So the included lense would be like a 27-83?

Talking about adapters. If I buy the original Sony Alpha mount adapter, will the ratio still be 1.5x for alpha lenses as it is with the E-Mount ones? Any tests with AF on SAM and SSM lenses? Have seen some complaints at Amazon reviews that AF is slow.

At last, I've seen adapters for other lenses (Nikon, Canon, etc) that will allow only manual focus. Any experiences with some of them? Are they worth the 20-30 bucks they cost? Is the focal length ratio then still 1.5x?

Thank you and regards...
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Old Jun 7, 2011, 8:35 AM   #2
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The focal length equivalent ("Crop Factor") is a function of the size of the image sensor, and so varies with the body not the lens. The adapters are so that lenses that were designed to focus on image sensors that are farther away, can be the appropriate distance to focus on the image sensor on the very thin NEX body. The Sony A-Mount to E-Mount adapter does that one better by adding autoexposure and autofocus as well. But since the NEX bodies don't have AF motors like the Alphas, the lenses must have their own AF motors, like Sony's SAM lenses, Sony's and Minolta's SSM lenses, Sigma's HSM lenses and Tamron's USD and PZD lenses.

Another difference that comes into play is that dSLRs like Sony's Alphas, use a Phase Detection Autofocus System, but the NEX use the slower and less accurate Contrast Measurement Autofocus System. Also, the NEX bodies use a smaller, less powerful battery than most of the Alphas, plus the adapter uses some, so less power gets to an A-Mount lens on a NEX than it would on an Alpha. The result is that an A-Mount lens will not focus as quickly on a NEX as it does on an Alpha.

Lastly, Alphas use Sensor Shift Image Stabilization, which was left out of the NEX bodies to make them smaller and less expensive. So if you want image stabilization you can only get it in the lens. Currently, Sony's 18-55 and 18-200 lenses are the only stabilized E-Mount lenses available, and most A-Mount lenses aren't stabilized. But Sigma's A-Mount OS lenses will be stabilized on NEX bodies.

There are some reports that some Sigma HSM lenses won't AF on the A-Mount to E-Mount adapter, but there doesn't appear to be a pattern, so you should try it before you buy it.
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Old Jun 7, 2011, 9:21 PM   #3
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Wow, thank you for such a precise answer. Seems that Sigma or Tamron will be a good way to go.

Now, I am interested in buying the 16mm E-Mount lense as it's small and seems good for taking good pictures at parties and have the camera look like a compact P&S. Is this lense a good choice? I was considering some fixed Sigma or Tamron but they all are 50mm, but was looking for a shorter focal lenght. Is it worth buying some Alpha lense or is the E-Mount 16mm ok?

About zomm lenses, I'm interested in buying something like 50-200 or 50-300 (or similar, I know they are not exactly these ranges), but it would be a lense for special pictures, not the most used one. Not sure if IS is really needed, I have used a Sigma 70-300 on a non IS Pentax and it is really useable.

Will have to see the Sigma OS, but they sound to be expensive, will have to see what's a better deal. The 18-200 E-Mount lense has a prohibitive price.
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Old Jun 7, 2011, 9:31 PM   #4
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I've seen some good results from the 16mm E-Mount lens, and the people that have it seem to be pleased with it.

Sony will be releasing some E-Mount lenses sometime in the near future, and I suspect that one of them will be a 55-200, so you might want to wait.
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Old Jun 8, 2011, 3:59 PM   #5
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OK, for the meantime I will look for the 16mm one; too bad I got a good deal but will get the camera delivered until next week.

Will have to see how expensive these lenses are, i am not quite a fan of paying 800USD for a lense for a 500USD camera.
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Old Jun 8, 2011, 4:16 PM   #6
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Quote:
Originally Posted by schmiedel View Post
Will have to see how expensive these lenses are, i am not quite a fan of paying 800USD for a lense for a 500USD camera.
You ain't seen nothin' yet.

If you're not in a rush, you might want to wait for the new 30mm f/3.5 Macro ($250, just like the 16/2.8) that was just announced. 30mm is a good focal length on an APS-C sensor, and macro lenses tend to be very sharp. Plus, f/3.5 isn't a lot different from the f/2.8 maximum aperture of 16mm lens. And there's the "macro" thing in case you ever need it.
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Old Jun 13, 2011, 10:42 PM   #7
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AFAIK, that lense was announced by Sigma, or will Sony release one with these specs too?

I received my camera this Friday and it is awesome, really happy with what I got. However, the 55mm max range is a bit short for my use. However, I rarely use a bigger zoom lense. Is there some cheap zoom lense (any brand, without AF is OK) that could be used with the camera with some cheaper adapter?
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Old Jun 13, 2011, 11:11 PM   #8
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Quote:
Originally Posted by schmiedel View Post
AFAIK, that lense was announced by Sigma, or will Sony release one with these specs too?
That lens was announced by Sony.
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Old Jun 14, 2011, 10:54 PM   #9
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OK, thank you. However, the Sony lense is a macro lense and its previews don't seem too promising, I see myself more excited about the Sigma 30mm f/2.8...

Now one question, let's say I had bought this lense:
http://cgi.ebay.com/ws/eBayISAPI.dll...3#ht_537wt_901

How could I know if it will autofocus or not on my camera with the Sony alpha adapter? I really want a bigger lense but without having to spend too much, I would rather spend 200 bucks on a 30mm lense that I will use very often than on a telephoto which I will use but wouldn't be a daily lense.
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Old Jun 15, 2011, 6:08 AM   #10
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Only lenses with their own AF motors will AF on a NEX. For Sigma, that means only HSM (Hyper-Sonic Motor) lenses will AF. And, unfortunately, not all Sigma HSM A-Mount lenses will AF. As I wrote in the last paragraph in my post above, some Sigma HSM lenses don't work, and since there doesn't seem to be a pattern, you can only know by trying it first.
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