Next logical lens for beginner

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Moab Man

Senior Member
That's going to be more of an outdoors lens at 50mm. Not many rooms have the working area. Just so you know what you're getting set your kit lens to 50mm and see if that works for you.
 
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DraganDL

Senior Member
"it doesn't say dx in the name. Is that an issue?" It sure doesn't say - for the time being, there is NO prime 50mm that would be "DX only''. So, it will not be an issue***. Relax and take a lot of good shots with this excellent lens:cool:!

"Is it that much better than the 50mm 1.8". No, it is not - the difference in price comes as a result of an additional aperture value (this lens is a notch "brighter" or "faster" than 50mm f/1.8 AF-S) . The construction had to be more carefully devised as to avoid degradation of the photos taken at f/1.4.


edited: *** like it's been said before, within this post - with the 50mm mounted on a DX camera (like D3100) you will have an angle of view which equals a 75mm lens mounted on a full frame (or a 35mm film) camera. Instead of "standard" lens, you will have a "portrait lens" or a "mild telephoto lens", so to speak.
 
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Eob

Senior Member
DraganDL said:
"it doesn't say dx in the name. Is that an issue?" It sure doesn't say - for the time being, there is NO prime 50mm that would be "DX only''. So, it will not be an issue***. Relax and take a lot of good shots with this excellent lens:cool:!

"Is it that much better than the 50mm 1.8". No, it is not - the difference in price comes as a result of an additional aperture value. The construction had to be more carefully devised as to avoid degradation of the photos taken at f/1.4.

Read more: http://nikonites.com/d3100/18488-next-logical-lens-beginner-5.html#ixzz2otLQ9h3b

edited: *** like it's been said before, within this post - with the 50mm mounted on a DX camera (like D3100) you will have an angle of view which equals a 70mm lens mounted on a full frame (or a 35mm film camera). Instead of "standard" lens, you will have a "portrait lens" or a "mild telephoto lens", so to speak.
Click to expand...

I wish I knew about the cropping with the 3100 before I got it. I just looked at the 35mm f/1.4... $1600 refurb. Gulp!
 
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DraganDL

Senior Member
You don't have to buy 35mm f/1.4. There is also a "DX" 35mm f/1.8, at very, very affordable price, even if it's a brand new one. And don't let this "cropping" confuse you: IT IS NOT true that this is (only) a disadvantage. Take exactly this 50mm lens for example: for a 200$ (50mm 1.8) you get the lens which can be used for taking EXCELLENT portraits, whereas for the full frame you would have to buy much more expensive lens, say, 85mm 1.8...
In real life it means that the "DX cropping" is advantage at the telephoto end of the lens line-up, so to speak, though can be a disadvantage at the wide end of the line... All depends on your needs, all is a matter of your perspective...

http://goo.gl/15LKM
 
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Eob

Senior Member
So, with lenses that are dx, are the focal lengths accurate on the d3100? As was suggested, I put on my kit lens and put it at 50mm and took some shots to see if that was a good length for me to take indoor photos. But, my kit lens is a dx lens, so does that mean to test what the non dx 55 1.4 or 1.8 would look like, Id have to use my telephoto at 75mm? I love taking pictures, hate math! :p
 
Horoscope Fish

Horoscope Fish

Senior Member
Evacares said:
So, with lenses that are dx, are the focal lengths accurate on the d3100?
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Yes, they will be accurate. 35mm or 50mm, or whatever focal length, is just that and it will never change.

Field of view changes based on the sensor size (DX or FX) with the DX having a smaller field of view but that's all.

Personally I think the whole DX crop factor is waaaay over-thought. It's a simple change is FOV, that's all.

.....
 
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DraganDL

Senior Member
Agree with what stated by Horoscope Fish . The value of focal length is a value of focal length. DX or FF means only that the lens either covers both formats or not. Thus, whatever lens's focal length you find suitable for your needs in terms of "what-you-see-is-what-you-get" (field of view) will do on D3100, no matter is it a DX designated or not - if you found it to be around 50mm (using your kit-lens as a reference), then go for a prime 50mm...
 
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nickt

Senior Member
I find fx vs dx much easier to explain to old film guys... you take your 35mm negative. With your scissors, cut roughly a 1/4" off the top, bottom, and each side, then print that cropped negative at 4x6 as usual. That's dx.
 
Whiskeyman

Whiskeyman

Senior Member
The difference between an f/1.4 lens and a 1.8 lens is about one-half a stop (.65 is closer to it). So, all other things being equal, you can use a shutter speed about 65% faster with the f/1.4 than the f/1.8 at max aperture.

And, with all else equal, the depth of field of the f/1.4 is less than the f/1.8.

When I purchased my 50mm and 85 mm lenses, I went with the f/1.8 versions, and will do the same when I purchase a 35 mm prime, because the above trade-offs weren't worth the greater lens prices to me. Even though I shoot a lot in low-light situations, the loss of depth of field isn't worth the extra speed that I get with the f/1.4. I just raise my ISO a stop and use a monopod.

If you go with FX (full-frame) lenses, there is another supposed advantage over DX: the DX sensor utilizes the center of the lenses projected image, which is sometimes call the "sweet spot" due to its superior image qualities.
 
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Eob

Senior Member
nickt said:
I find fx vs dx much easier to explain to old film guys... you take your 35mm negative. With your scissors, cut roughly a 1/4" off the top, bottom, and each side, then print that cropped negative at 4x6 as usual. That's dx.
Click to expand...

That doesn't sound good at all!
 
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Eob

Senior Member
DraganDL said:
Agree with what stated by Horoscope Fish . The value of focal length is a value of focal length. DX or FF means only that the lens either covers both formats or not. Thus, whatever lens's focal length you find suitable for your needs in terms of "what-you-see-is-what-you-get" (field of view) will do on D3100, no matter is it a DX designated or not - if you found it to be around 50mm (using your kit-lens as a reference), then go for a prime 50mm...
Click to expand...


So, to simplify, my dx kit lens at 50mm looks like 75mm because its cropped... And a non dx 50mm fixed lens will look cropped in the same way when put on my d3100?

To get in closer for indoor shots, I should get the 35mm not the 50?
 
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Eob

Senior Member
Whiskeyman said:
The difference between an f/1.4 lens and a 1.8 lens is about one-half a stop (.65 is closer to it). So, all other things being equal, you can use a shutter speed about 65% faster with the f/1.4 than the f/1.8 at max aperture.

And, with all else equal, the depth of field of the f/1.4 is less than the f/1.8.

When I purchased my 50mm and 85 mm lenses, I went with the f/1.8 versions, and will do the same when I purchase a 35 mm prime, because the above trade-offs weren't worth the greater lens prices to me. Even though I shoot a lot in low-light situations, the loss of depth of field isn't worth the extra speed that I get with the f/1.4. I just raise my ISO a stop and use a monopod.

If you go with FX (full-frame) lenses, there is another supposed advantage over DX: the DX sensor utilizes the center of the lenses projected image, which is sometimes call the "sweet spot" due to its superior image qualities.
Click to expand...

Thanks, that explanation helped a lot. 65% faster for twice the price sounds reasonable. Does the 1.8 still work well for kids moving around indoors? I have a birthday party to shoot soon with twin little boys.
 
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DraganDL

Senior Member
"So, to simplify, my dx kit lens at 50mm looks like 75mm because its cropped... And a non dx 50mm fixed lens will look cropped in the same way when put on my d3100?"


Yes: you put a 50mm full frame lens on a D3100 and your angle of view (or: width and height of the scenery viewed through the camera) equals what you would have with a 75mm full frame lens mounted on a full frame camera...

"Does the 1.8 still work well for kids moving around indoors?"

Yes, granted. But, with the 50mm you will probably mostly be able to take photos of the upper parts of their "postures" (head, down to the waist) within the room as large as 5x6 metres, with the furniture and all... You would be better off with a 35mm 1.8 DX, - cheap, yet GOOD lens - (or wider, though pricier full frames of 24mm or 28mm)...

 
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Whiskeyman

Whiskeyman

Senior Member
Evacares said:
Thanks, that explanation helped a lot. 65% faster for twice the price sounds reasonable. Does the 1.8 still work well for kids moving around indoors? I have a birthday party to shoot soon with twin little boys.
Click to expand...

Of course, the answer depends upon the scene lighting. Were it me, I'd buy the f/1.8 and a good flash instead of the f/1.4; the f/1.8 should be fine for this. At maximum aperture, chances are that you're not going to get both twins in good focus without stopping the aperture down some, and with a good flash you'll get enough light onto the scene.

In this instance, you likely can successfully use your kit lens with an additional flash, if you don't like the on-camera flash on your camera.

Good luck.

WM
 
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