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.
2075035
You can choose between 60, 90 and 120 deg angles in the menu. Even the 120 isn't really fish eyed where as normal fish eye lenses distort around the edges. Hope this helps.
1818947
good question. the iris in this unit is theoretically F1.0 and should pass 100% of whatever the lens is giving you to begin with with w/o loss until you close it down.. just not something I ever worried about.
107802
That equation is correct... it is called spherical equivalent. With a -3.00 sphere and -3.25 cylinder, your spherical equivalent is -4.50. Keep in mind this will give you pretty decent vision - good enough to see at a reasonable distance, but this will not be equal to a full spectacle prescription. I am an optometrist.
759247
Even better. The 1.4 is rock solid compared to the flimsy 1.8, and slightly faster. Ten times as expensive, but may be worth it. If you're still thinking of adding a new zoom to your arsenal, look at the 24-105L, as well. It's pretty much a coin toss, as far as IQ, with the 24-70L, but it adds IS. So, it's one stop slower, but it gains about 3 stops due to the IS, so it's actually better for low-light than the "faster" lens. And longer, too.
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.
41418
That is a very broad question. Everyone has different sensitivity. I can personally say I bought the .5 instead of 1.0 because I read it is best to work up to 1.0 because it is powerful. If you don't have sensitive skin then try 1.0. I did what was best for me when I purchased it. When I run out of .5 May up it to 1.0.
123475
Good question. The difference is better optics at 1.4f stop, or wide open. If you shoot wide open all the time, then you might want to consider that extra expense. On the other hand, if you shoot occasionally wide open, this lens (400) is great and I have liked shooting with it.
49300
You need to know your glasses prescription. If you're nearsighted, (need correction for distance sight your rx will be a negative number. The lenses come in 0.5 increments. For example I have a -3.75 correction. Since it is in between correction options I ordered a -3.50. (If your in between order the lesser strength). If you are far sighted the correction will be a +.(ie reading glasses). Hope that helps.
1796673
I'd put it in the 1.4 group... I love this lens. Tact sharp and can focus up close to your subject.
851241
I tried both side-by-side. F/3.5 model focused noticeably faster in low light. It also has a better build. On the other hand it is larger, heavier and uses more expensive 82mm filters (F/4-5.6 uses 77mm filters). Plus at the time I purchased it, the 4-5.6 model cost $407$ at my local store and the 3.5 model cost $649, which is $250 difference. At that price difference you might as well get excellently reviewed Tokina 11-16 constant F/2.8. Some food for thought
2121873
I did mine at least 4 months ago. I noticed the lenses started to have a haze/showing sign of yellow already. Understand, I live in Houston, Texas, where we got sunshine most of the time, including winter.
523655
I would say EF-S 17-55mm f/2.8 USM IS. You get greater bokeh at f/2.8. Although the weather sealing and better construction of the 24-105 is pretty sweet too.Edit: I forgot to mention that f/2.8 is better than f/4 in low light. But I think you know that already =)
1228149
I do not have this problem. Some say it works above 4, but it works on my lens, which goes all the way to 1.8. I don't know why some people experience this, though.
1276663
I've been using the 14-24mm f2.8 for a year now. Tack sharp! No lens creep. I was worried about no filters to protect glass also. Built in lens hood protects front element well enough. Lens cap fits OVER hood when not in use. I am comfortable with that. No VR doesn't seem to be an issue, as a lot of light comes through the glass and allows higher shutter speeds I feel. I generally shoot with a standard ISO of 400 to kick it up the speed a bit. Great lens. I also use the 24-70mm and 70-200mm lenses, both at f2.8 as well. Throw any pic from these three lenses on you monitor and you could cut yourself on the sharpness. LOL. I've been using the 14-24mm f2.8 for a year now. Tack sharp! No lens creep. I was worried about no filters to protect glass also. Built in lens hood protects front element well enough. Lens cap fits OVER hood when not in use. I am comfortable with that. No VR doesn't seem to be an issue, as a lot of light comes through the glass and allows higher shutter speeds I feel. I generally shoot with a standard ISO of 400 to kick it up the speed a bit. Great lens. I also use the 24-70mm and 70-200mm lenses, both at f2.8 as well. Throw any pic from these three lenses on you monitor and you could cut... » Read More I've been using the 14-24mm f2.8 for a year now. Tack sharp! No lens creep. I was worried about no filters to protect glass also. Built in lens hood protects front element well enough. Lens cap fits OVER hood when not in use. I am comfortable with that. No VR doesn't seem to be an issue, as a lot of light comes through the glass and allows higher shutter speeds I feel. I generally shoot with a standard ISO of 400 to kick it up the speed a bit. Great lens. I also use the 24-70mm and 70-200mm lenses, both at f2.8 as well. Throw any pic from these three lenses on you monitor and you could cut yourself on the sharpness. LOL. « Show Less
1216096
I have different sizes for different areas. I have been using the 1.0 for my face, 0.5 for around the eyes and 2.0 for body areas. I hope this helps. I actually did my face last night.
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!