Sorry, I'm a bit puzzled. What's the difference between -4.0 and -4? I'm from China and 400 degrees of myopia. Should I choose -4.0 or -4 or 4?
82129
I think -4.0 and -4 are the same. If you are near-sighted, you should choose negative.
40105
The 1.4 is going to give you better bokeh (that beautiful blurry light) and a shallower depth of field. It also lets more light in. Hope that helps!
678605
In my opinion it depends on what your main reason for using the lens is. If you don't NEED the 2.8 then go with the 4, I don't think IQ is dramatically better or worse. Unless there was ever a time while you were using the f/4 that you were like "man I wish I could stop down to 2.8," I would just stick to the f/4.Edit: Just saw on another reply you said something about portraits, if you are going to use the lens for portraits at all the 2.8 is amazing, the bokeh is simply stunning.
678606
Well, the f/2.8 is a much newer lens and is superior to the f/4 in many performance aspects (AF speed, accuracy, etc). Don't get me wrong, though. The f/4 is still a solid performer. Sometimes, the f/4 captures better photos in the f/4-f/5.6 range than the f/2.8 does in that range.Now, since you stated that weight is a concern for you, I'd point out that the f/2.8 is a whole two times heavier than the f/4. The f/4 is also half the price of the f/2.8.If you shoot in low-light or indoor, then the f/2.8 is for you. If you shoot outdoor and have plenty of light, then the f/4 is just as good. Well, the f/2.8 is a much newer lens and is superior to the f/4 in many performance aspects (AF speed, accuracy, etc). Don't get me wrong, though. The f/4 is still a solid performer. Sometimes, the f/4 captures better photos in the f/4-f/5.6 range than the f/2.8 does in that range.Now, since you stated that weight is a concern for you, I'd point out that the f/2.8 is a whole two times heavier than the f/4. The f/4 is also half the price of the f/2.8.If you shoot in low-light or indoor, then the f/2.8 is for you. If you shoot outdoor and have plenty of light, then the f/4 is just... » Read More Well, the f/2.8 is a much newer lens and is superior to the f/4 in many performance aspects (AF speed, accuracy, etc). Don't get me wrong, though. The f/4 is still a solid performer. Sometimes, the f/4 captures better photos in the f/4-f/5.6 range than the f/2.8 does in that range.Now, since you stated that weight is a concern for you, I'd point out that the f/2.8 is a whole two times heavier than the f/4. The f/4 is also half the price of the f/2.8.If you shoot in low-light or indoor, then the f/2.8 is for you. If you shoot outdoor and have plenty of light, then the f/4 is just as good. « Show Less
47633
So you have the option to have a different strength for each eye? I did not when getting swim goggles and went with something in the middle, so in your case, either 2 or 2.5. I have one eye too strong, one not enough, but that does not seem to be a problem.
1177291
Depends on what your prescription is. The camera has a built in -3.0 to +1.0 diopter adjustment. You want to buy the one that will allow you to match your prescription.E.g. If you wear +2 prescription, get the +2 and dial it down by 1. You would only need the - if you have to go further than the -3 that is built in. However, I have found that I do not use the diopter. When I have my glasses off, the images on the LCD are blurry. So I shoot with my glasses or contacts, so I can still view the images on the LCD.Hope this helps you decide.Chris
2041779
There is at least one good comparison of the two lenses on youtube. Check out the videos and determine for yourself which lens fits your needs better. The f/1.4 is my first non-L lens; the add'l cost and weight made the f/1.2 less of a good fit for me.
2166157
The 1.4 on the lens refers to how low the aperture goes. Aperture is how large or small the opening in the lens is and you can change it to control depth of field. This lens goes down to a 1.4 which is a really low number meaning a really LARGE opening in the lens allowing for a super shallow depth of field which can create those dreamy "blurry" backgrounds that people love.
2004640
Which one did you finish up with? I'm interested because you said that you shoot mainly lanscapes, so why would you part with the 17-40mm? If your option had been for the 16-35mm f2.8L, I could have understood the reason, but a 24mm lens on any new camera (assuming it's not a film body, 5D or 1Ds) is only going to give you 31mm (1D) or 38mm (the rest). Not much good for landscape work.BTW, the 24-70mm eats the 24-105mm alive when it comes to contrast and sharpness, IS or not!
1372697
Dennis, It depends on what you deem effective. � I've shot mine wide open at f/4 but it may be a little soft in the corners for your liking, doesn't bug me. As long as you have plenty of light f/5.6 is pretty amazing with your subject at about 40-60 feet. f/8 is great as long as you have either the sun or if you don't mind pushing the ISO to keep you shutter speed above at least 1.5x the focal length. I find 1/500th-1/800th ish is plenty, and I don't have the hands of a surgeon by any means. Some of my sharpest images have come from this lens.On Full Frame I use it with the Tamron 1.4x TC to achieve the length you have already with the D7100 beinng DX. Dennis, It depends on what you deem effective. � I've shot mine wide open at f/4 but it may be a little soft in the corners for your liking, doesn't bug me. As long as you have plenty of light f/5.6 is pretty amazing with your subject at about 40-60 feet. f/8 is great as long as you have either the sun or if you don't mind pushing the ISO to keep you shutter speed above at least 1.5x the focal length. I find 1/500th-1/800th ish is plenty, and I don't have the hands of a surgeon by any means. Some of my sharpest images have come from this lens.On Full Frame I... » Read More Dennis, It depends on what you deem effective. � I've shot mine wide open at f/4 but it may be a little soft in the corners for your liking, doesn't bug me. As long as you have plenty of light f/5.6 is pretty amazing with your subject at about 40-60 feet. f/8 is great as long as you have either the sun or if you don't mind pushing the ISO to keep you shutter speed above at least 1.5x the focal length. I find 1/500th-1/800th ish is plenty, and I don't have the hands of a surgeon by any means. Some of my sharpest images have come from this lens.On Full Frame I use it with the Tamron 1.4x TC to achieve the length you have already with the D7100 beinng DX. « Show Less
21263
i would get the -3 that way you don't cause disorientation, because water as is does have refraction, so i would go with the lowest diopter.
1420442
I use the 1.4X as well as the 2.0X between my Nikon D-200 and the 80-400 f4.5 Nikor D lens. The optical quality is very good for the price. Plan on using a tripod more often because you will loose a stop and end up shooting with a slower shutter speed. Happy Shooting!
382298
The 2.8 gives you slightly better VR and one more stop over the f4. You could always take advantage of Amazon's 30 day return policy and try the f4. If it works well for you, keep it. If not, return it for the f2.8 model. Your current lens has NO VR, so either lens would be a big improvement.
77652
Yes, somebody here said +.2 or something like that.It is minor but present; makes screen seem just a little bit bigger.You can get them as prescription lenses if you need more.
1509181
I recently had cataract surgery and I am now farsighted. Standard 5X magnification didn't help at all, so I went for the highest one I could find. If a 5X doesn't work at all for you, go for the highest magnification.
766794
Blue lenses are excellent for all types of light. We currently have the +2.5 in stock but not the +3. Hope that helps.
107885
Go higher! under water there is less visibility, so anything that gives you the edge, I would go for... Anyway there is some eye adjustment at any point and at that level half a Dioptric is almost negligible (my unprofessional opinion)