Skiver '76: sigma

Showing posts with label sigma. Show all posts

Monday, June 30, 2008

Sigma 50-150mm f/2.8

Sigma 50-150mm f/2.8 is my main lens when shooting sports. It is a handy reach for a gym (Roller Darby) or a dirtjump/BMX track. Aperture of f/2.8 means that shooting at ISO800 in a badly-lit gym will often enough give me acceptably short times to freeze action with shutter speed and/or use flashes at lower power (so they recycle quicker).

The focal range of 50-150mm on a Nikon DX camera is the same as a 75-225mm on a full-frame (35mm), which is pretty much the standard sports telephoto range all the way from film times - but with this lens it comes in a surprisingly compact package! The price you pay for weight savings is that the lens is DX-only (Sigma call it DC). The HSM version auto-focuses even on Nikon D40/x/60 cameras.

When buying this lens I was replacing the Nikon AF-S 55-200mm f/4.5-5.6 VR which I was disappointed with for a number of reasons. You get what you pay for with that lens, at least in build and physical construction. I dunno why I was expecting a pro lens at a hundred'n'fiddy squid. Aperture of 5.6 is useless for trying to freeze fast moving people with low shutter speed (VR or no-VR has no effect on that). I needed something with a tough build and f/2.8 or faster.

Looking at the options that I could afford and was willing to carry around, I chose this Sigma lens above the more expensive and heavier options. I played with the idea of one of the AF-S 70/80-200mm f/2.8 Nikons or Sigma's version of the same range. I haven't regretted this choice since I got the lens about 6 months ago.

Nothing external moves on this lens - it has internal focusing and zoom. The whole thing feels very solid; lot of the exterior seems to be metal - the two rings each have their own rubber pattern and turn very smoothly. The lens is not sealed against weather, but it does have a lot fewer "entry points" for dirt/moisture than other lenses in this price range. It is also affordable compared to (supposedly much better, but much larger/heavier) Nikon f/2.8 glass which costs 2-3 times as much.

The only thing I mind is no optical stabilization. It would have been useful in a telephoto lens combined with f/2.8 aperture. Focusing from 1m is OK but not great.

I also feel a lot of wrist strain (biking injuries catch up) when using a telephoto with the D40's small grip - although that's something that would be even more of an issue with the Nikon AF-S 70-200mm f/2.8 VR that I was thinking of as my first choice until I found this sturdy little thing at 50% of what I was about to spend.

There are some reviews at:
Pop Photo, ePhoto Zine,
and a Flickr Group

Sunday, April 13, 2008

Sigma 30 mm F1.4 EX DC HSM

If you own a Nikon D4o(x) or D60 there is no other lens like this one. Nikon is being a bit slow catching up with itself and are only very few AF-S prime lenses available at this point. Since the above bodies will not focus with lenses without an internal motor, one gets no choice when choosing a 'normal' lens for a D40.

The lens was launched by sigma in February 2005. A lot has been written on various forums about Sigma's quality control, good samples, bad samples and corner softness of this lens. I don't know much about these things. I picked my lens from Jessops and never bothered photographing a chart or even a brick wall. In real-life use I haven't noticed any problems. At f/1.4 the depth of field is really shallow, to the extent that focusing on the tip of somebody's nose will render their ears/eyes soft, but that's the price that has to be paid for being able to take pictures at reasonable shutter speeds in very dark places.

Shallow depth of field: shot at 1/40s at f/1.4

Optically speaking it is excellent for my purposes. There is no distortion; there is no CA to speak of (anyway you don't really have to deal with CA in low-light shots). The colours are nice and when you stop the lens down a bit it is sharp and crisp. It has more than enough definition for my camera's chip and the bokeh is very acceptable. I haven't noticed much flare even with light sources in the frame; bright lights get a nice eight-pointed star.

CA: 1/250 at f/5.6 - some (out of focus) CA is noticeable in the top part of the picture.

The lens belongs to Sigma's EX range - supposedly that means better quality. Personally, I can't say anything about non-EX Sigma lenses - however compared to the kit lens or to the Nikon 55-200mm VR, this lens is much better built. The barrel and the petal-shaped hood are both finishes in nice satin paint, the lens comes in a very good box-shaped cordura case with a belt loop. Although the lens thread is made of plastic, the bayonet and most of the outer barrel is metal and the lens has a reassuringly solid feel. I have knocked mine around a little bit (dropped it with the camera from about waist high on concrete, shot with it in mild rain) and it seems to be holding up very well, except for a few small places where I actually managed to scratch the paint and realized that the outer barrel is indeed made of metal.

This is the second lens I bought for my Nikon D40. It quickly became my every-day lens and I really love it. I would highly recommend it to anyone with a Nikon D40/x or D60 over the kit lens (which is slow and plastic) or the Nikon 50mm f/1.8 which won't auto-focus on those bodies. It is affordable (just about), fast, solidly built and compact. Don't let yourself be put off by a few vocal nit-pickers on certain forums, or look for a different lens if you do take pictures of well lit brick walls. There is no reason you'd want this lens for a Nikon D3 or a Canon 5D (in fact you could not even use it on a full-frame body - because it is a DC lens that does not cover bigger than APS-C size sensors). There is one fewer reason why get this over the cheaper 50mm f/1.8 if your body can auto-focus with non-HSM or non-AF-S lenses (Nikon D80 upwards), except HSM offers reportedly faster focusing. Ken Rockwell says :-) that if you shoot Canon the Canon 28mm f/1.8 EF is a better choice for less money. I don't know about Canon. I know that for entry-level Nikon SLRs it has no competition in its class, but it is very far from a "one-eyed king of the blind"; it is actually a really good lens.

Focal Length: 30 mm
Maximum Aperture: F1.4
Minimum Aperture: F16
Lens Construction: 7 Elements in 7 Groups, 2 ED elements
Angle of View: 45°
Diaphragm: 8 blades
Minimum Focus Distance: 40cm
Maximum Magnification: 1:10.4
Filter Size: 62mm
Dimensions (diameter x length): 76mm x 59mm
Weight: 406.7g

Links to other reviews:

Flickr groups:

Wednesday, April 09, 2008

Sigma: 10-20mm f/4-5.6, 1.4/30mm & 50-150mm f/2.8

I have been thinking about posting my own experience on these three lenses by Sigma for some time:

There are some good reviews out there already, but the rest seems to deal with distortion when photographing graphs, chromatic aberration when shooting trees against bright sky or finding "a good copy" of the lens through shooting a brick wall - retuning the lens to the shop - shooting a brick wall... Not the kind of stuff that I like to do. Other thing that bugs me is that most of these reviews are written by people who only just got the lens, tested it over a weekend and did a write-up. Do their opinions still hold months after using the lens in real life? Who knows? Did they have to please the shop/importer of the gear? Not me - I paid for all my equipment.

Over the next three days I will post some real-life experience with the above three babies. I don't have a lab, charts or methodology. I have months/weeks spent taking pictures with the above three instead.