30mm f/1.4 EX DC HSM Lens for Nikon Digital SLR Cameras

Update: 23 Aug 2016-----------------------------After shooting some more with my lens, I noticed several instances (about 20%) of auto-focus misses. Reading a review of this lens on lenstip.com, I found out that auto-focus miss with this lens is known issue.After a little more testing with this lens, I found that auto-focus is most consistent and accurate when the surface focus target is perpendicular to the center of the lens. When focusing on a target that is angled, AF accuracy gets thrown off and the lens tends to back focus. AF accuracy can also be thrown off when focusing on objects with smooth, curved or shiny surfaces.When using a measuring tape to measure focus accuracy, make sure you don't focus directly on the measuring tape, which will be at an angle. Instead focus on a target that is at right angles with the lens. The measuring tape should be placed to the right or the left of the target.I am attaching a link to a youtube video that explains how to properly measure focus accuracy using a measuring tape and a target. You will find the link in the Comments section.Original review--------------------I bought this lens for my Sigma SD15 DSLR, where it has an equivalent focal length of 51mm, thus making it a "standard" lens. (The Sigma SD15 system has a crop factor of 1.7. On the SD1 Merrill, which has a crop factor of 1.5, the equivalent focal length will be 45mm.)It is reasonably sharp in the center wide open, and thus can be used for low light photography including portraits, albeit the depth of field is pretty narrow. It becomes tack sharp when stopping down to F2.8. On the SD15, the edge sharpness is also very good by F4.0. It can certainly be used for landscape photography when stopped down to F5.6, when the edge sharpness is almost as good as the center.The bokeh in this lens is smooth and pleasing, although not quite as "buttery" as the bokeh on the Fuji XF 35mm F1.4 lens. The lens has good contrast and generally good control over lens flare. Having "only" 7 glass elements, I love the way this lens renders tonal nuances and micro-contrast.Based on other reviews of Sigma 30mm F1.4 lens, it appears that there have been some bad copies of this lens. For example, some have experienced calibration issues resulting in a "back focus" or "front focus" problems. Thankfully the copy of the lens I received was calibrated perfectly, and I had no issues focusing accurately with it.There is a caveat, though, that there is field curvature present with this lens. When focusing on an object in the center, off center objects will need to be slightly nearer to the camera than the plane of focus in order to achieve sharp focus. This is not an issue if one knows how to deal with it, including stopping down in group shots if necessary.There is slight CA of the cyan/magenta variety, but this is easily corrected in post processing.Overall this lens is able to deliver pretty stunning results on my SD15 camera.

This is one of the most controversial lenses ever, it seems. why all the fuss over this little guy? Simple, it cleverly exploits a hole in nikon's product lineup as a wide aperture (f/1.4) prime lens with HSM (hypersonic motor) at a price point just above nikon's older, slower 35/2 prime.Therefore nikon purists hate it with a passion, while 3rd party aficionados tend to have a more open mind.First off, if you're looking for something razor sharp at f/1.4 try zeiss or get over it. it's no fillet chef wide open, but that's not the point. the point is that you CAN use it at 1.4, which means it can shoot in light a 2.8 would be challenged by. also you can stop it down a few clicks and still be at 2.8, or shoot at f/2 or 2.2 and not be completely wide open.Second, while i'm sure there are sample variations out there, don't be put off by doomsayers on internet forums. opinions of actual users are one thing, but i dont know how people who have never used the lens can qualify it whatsoever.(but if you do order this lens, make sure its from a vendor with a good return policy. check for front focus issues when you get it; if you have a problem, sigma will recalibrate the lens. saves them money in the QC department, but at least they have good customer service.)for the record, i own three sigma lenses, all EX series, all bought online, and they all worked perfectly fine from day one.There are two categories of folks who will be looking at this lens: d40/d40x/d60 users and everybody else.for a d40/60 kinda person who wants to take no-flash, low light pics, there are no other options in this focal length and aperture class with an internal motor. period. you'd have to go to the micro-nikkor 60mm or 105VR to get an AF-S prime. sigma is coming out with a 50/1.4 HSM, but the 30's "normal" perspective is better suited for DX camera sensors with their 1.5 crop.nikon d80/200/300/700 owners can use any of nikon's (or sigma's) primes with full AF capability. unless you absolutely need f/1.4, the nikon 35/2 is cheaper and probably sharper. it doesn't have an internal motor, though, so for low-light action shots, the sigma is better suited for that application. but if you just need something inobtrusive for street shooting, candids, or a lower-profile lens, and arent worried about max aperture or AF speed, go for the 35/2.okay, how about some pros and cons:Pros:--not a small lens but lightweight.--low profile and normal perspective perfect for street/doc and candids.-- 1.4 maximum aperture makes this perfect for extreme low-light shooting.-- shallow dof at wide apertures results in creamy bokeh (out of focus elements)--HSM ensures fast AF; will work on D-series cameras without internal motors.-- takes 67mm filters.--sharp in the center at all apertures.--contrasty IQ--using fixed focal length lens forces you to focus on composition.-- EX build is better than sigma's bottom-barrel lenses, plus EX lenses have add'l 3-year warranty.--makes a good low-light solution for folks with slow variable-aperture kit lenses (i.e., 18-55, 18-70, 18-135, 18-200)Cons:--1.4 aperture gives extremely narrow depth of field. this makes this lens extremely tricky when shooting wide open, as shallow depth of field can be mistaken for focus issues.-- focal range is not as versatile as a zoom-- how much are you really gonna shoot at 1.4?--IQ not as impressive as cheaper nikkor 50/1.8--soft corners at almost all apertures (this matters less than you might think in low-light situations)--some known QC issues (which may be somewhat exaggerated)--more expensive than nikon 50/1.8, 50/1.4, and 35/2 primes.overall: recommended for d40/d60 users, low-light/available-light fanatics, street/doc shooters, people who will stay with DX for a while. not recommended for nikon nazis, or folks who may eventually migrate to FX.in practical use, this lens is probably more essential on an entry-level or mid level DSLR than a d300, d700, or D3. those cameras' improved high ISO performance means you can often stop down a 2.8 lens to f/4 in low light, lessening the need for a 1.4 aperture. on a d/40/50/60/80/200, however, you can keep the noise down in low light situations by shooting at wide apertures and not going above ISO 800.also, this is a DC lens, meaning that it is designed for DX sensors. FX-curious folks should probably get the nikkor 35/2 instead.while the 30/1.4 lens sees a lot of low-light use, its normal perspective and wide max aperture make it versatile in many conditions. i've stopped it down to f/8-f/11 and found it takes good landscape shots too. you never know when you might run into a situation where 1.4 is needed. it's a good one to have in the bag, just in case.