Sigma 8-16 f/4.5-5.6 DC HSM

Preface

I was looking to a wider addition to my TAMRON SP17-50/2.

After studying the web pages I came to a conclusion that the SIGMA 8-16/4.5-5.6 was the more tempting piece. First of all it is the widest ultra-wide lens available for the half-frame digital SLR and secondly the reviews of the lens were rather positive (especially the “highly recommended” conclusion at “photozone.de”).

Finally I bought the SIGMA.

I comes with a nice and very well protecting neoprem semi-soft case.

At the first glace you can see the lens is a big mama.

Since the SIGMA is slow, heavy weight and rigid, it is almost sure it must be a real optical performer.

Below I present my review of the SIGMA 8-16/4.5-5.6.

All the findings and comments are my own, individual and independent.

I’am telling only about what I have checked personally (nothing is told, overheard or read elswhere).

Please note that I have checked not a population of several lenses but just one single piece and all the article refers to that specific piece only.

Anyhow I am disappointed with the statement of the SIGMA engineers who told me any other copy of the lens would be exactly the same – please read it at the end of the article.

For a better reference I put a scale where each feature of the lens is scored in points.

According to my own hierarchy of priorities not all features are of the same importance hence you will find a three step scale as well as a ten step scale.

Chapter One: OPTICAL QUALITY

1/ Speed (2 of 5)

The SIGMA is slow, very slow. I can’t stop saying welcome to the large format lenses.

F4.5 at the wide end and F5.6 at the “tele’ end is to my taste at least one F-stop too slow.

What’s the fuss about since it’s a very wide lens so permitting for much slower shutter speed without the risk of blur?

With the SIMGA the viewfinder is a bit dim and when you shoot a low light interior (the focal length range tells it is an ideal lens for the interior photography), the picture in the viewfinder becomes really dark so you have to take your eye off the viewfinder to compare the real world with what you are actually going to photograph.

1/ Distortion (10 of 10)

When you attach the lens and look through the viewfinder you simply cannot believe what you see. Straight lines are straight. It is absolutely unbelievable that such a wide lens has so small distortion. Do note that in terms of 35mm photography the SIGMA has the angle of view equal to a 12mm lens at its wide setting!

(Of course when you hold the camera not vertically but play with it trying various angry angles, the lens will give you the typical wide angle distortion.)

This is definitely perfect lens for that purpose. Bravo!

3/ Resolution (11/30)

Let me refer the resolution of the sharpest lens I ever had i.e. the PENTAX DA 100/2.8macro and then to the commonly known and very popular zoom i.e. TAMRON SP 17-50/2.8.

Given that the center resolution of the a.m. Pentax is 100% and the Tamron’s is 60%, the SIGMA’s 8-12/4.5-5.6 falls around 80% in this comparision.

We have to admit the center resolution is not far from being excellent but it is only a one story.

The big problem, in fact a disaster, is that the resolution is extremely uneven across the frame and very poor everywhere outside the center.

I would classify the resolution of the SIGMA as follows.

a/ center of the frame: 8 of 10

b/ edges: 2 of 10

c/ corners: 1 of 10

To learn the sharpness of the lens I made a series of shots at wide opening and repeated the scenery at F8 (the mosct tempting focal length), exposed at ISO 200 and 1/250s.

As you can see the resolution characteristics of the lens is quite peculiar: it performs very good in the very center of the frame only; next, when stopped down, it performs much better in the area close to the longitudinal axis while it performs very bad at the edges and what we have in the corners I repeat it is a real disaster.

I’ve never had a lens with such poor edge and corner sharpness.

Additionally, the lens was evidently de-centered with the left edge of the frame performed worse than the right one.

Please imagine that the total area covered with numbers represent the frame.

Each number represent approximated sharpness of that part of the frame, expressed in percent.

People acquainted with the charts presented at “slr gear” should find themselves at home after a while.

Simplified resolution chart in percent of quality @8mm F4.5

6 6 12 12 12 12 12

6 6 25 25 25 15 12

6 25 50 50 50 25 12

6 25 75 100 75 25 12

12 50 100 100 100 50 25

6 25 75 100 75 25 12

6 25 50 50 50 25 12

6 6 25 25 25 12 12

6 6 12 12 12 12 12

Simplified resolution chart in percent of quality @8mm F8.0

6 6 12 12 12 12 12

6 6 25 25 25 15 12

6 25 50 50 50 25 12

6 25 75 100 75 25 12

12 50 100 100 100 50 25

6 25 75 100 75 25 12

6 25 50 50 50 25 12

6 6 25 25 25 12 12

6 6 12 12 12 12 12

It seems the resolution at the „tele” setting of the SIGMA is about 15-20% worse in general terms when compared with its wider setting, yet it is slightly more evenly distributed across the frame.

Obviously there must be something wrong with the lens.

4/ Vignetting (4 of 5)

The lens has shown some corner shading when checked while shooting a white wall of my house but in all the other photos the vignetting had almost no real effect even when shooting with the lens wide open.

5/ Chromatic Aberration (3 of 5)

Again I would compare the SIGMA to the TAMRON SP 17-50/2.8 and to my eyes the purple fringing of both lenses are on par. Of course there is a purple fringing on the extremely contrasty edges but it’s not so heavy. Could be better though especially at the wide end.

6/ Flare and Ghosting (1 of 5)

The SIGMA does not like direct sunlight and its too bad as with the lens that wide it’s not rare that you caught the sun somewhere in the frame. The lens produces not only typical lighting spots and “echoes” of the “iris eye” but it gives unpleasant strong smears that look like enormous sun beams. Having my highly positive experience with the SIGMA fisheye lens I’ve been very disappointed with such a poor performance of the SIGMA 8-16/4.5-5.6 when shooting against the light.

7/ Close focusing (2 of 3)

With is 24cm Minimal Object Distance the SIGMA is not bad yet some 5cm closer would help much to create stunning wide angle close up photos.

Chapter Two: MECHANICAL QUALITY

1/ Built Quality (5 of 5).

The lens is sturdy and rigid (appears to be all metal construction?). It gives you very solid feel. The tolerances are tight.

Personally I don’t like the coal dust like matt finish but it’s a matter of one’s taste rather than an argument to blame.

2/ Size and Weight (2 of 5)

With its 550 gram the SIGMA is a heavy piece of equipment. The front lens element seems to be very heavy and when the lens is attached you can feel the tandem camera-and-lens is unbalanced with the tendency towards turning the front of the lens down. After a 15 minutes hand held photo session you really feel very discomfortable.

3/ Filter size (no score)

Unfortunately, due to almost spherical shape of the front lens element no filter can be attached to the SIGMA.

4/ Autofocus (1 of 5)

Equipped with an ultrasonic drive the SIGMA produces very delicate bass-like sound during focusing.

The autofocus system performs well only in extremely contrasty scenery and with close subject, closer than 5m; otherwise it focuses the lens every time at a wrong point, one time showing strong Front Focus fault and strong Back Focus fault the other time.

Unfortunately the autofocus system is totally unreliable.

5/ Manual Focusing (5 of 5)

First of all I need to say that for me only Canon made lenses both zooms and focuses in the right way(I mean intuitive/natural way) i.e. you turn the zoom ring left towards the telephoto end and you turn it right towards the wide end; you turn the focus ring right towards the close distance and you turn it left toward infinity. The SIGMA at least focuses the right way.

You have full time manual focus override provision with this lens without prior switching its mode from AF to MF. That’s great.

The focusing ring operates very positively with nice heavy dumping preventing from accidental shifting the focus when your fingers touch the ring unintentionally.

My only remark is that both zoom and focus ring have the same texture – I’d prefer them to differ.

6/ Focusing Aids

a/ Distance marks (2 of 3)

The SIGMA has distance marks in both “m” and “ft” easily visible through a polycarbonate window but for me there are too less distances marks painted.

b/ DOF scale (0 of 3)

The SIGMA does not have any Depth-Of-Field scale marked on the lens. When photographing with an extremely wide angle lens everything looks sharp in the viewfinder but after you check the photo on your computer you will see not everything is sharp; you will notice there are subjects you would have them to be sharp while they are in the out of focus area or vice versa. When photographing landscapes/cityscapes and especially interiors the autofocus won’t tell you anything. Manual focusing, distance mark and DOF scale are the right tools. Without DOF scale you loose the control of the DOF and in most cases you only can guess what you’re doing.

Please don’t tell me it’s impossible or complicated to mark a DOF scale on the SIGMA 8-16/4.5-5.6.

...

After two days testing of the lens I returned the thing to the shop, reported all my complaints and requested another copy of the lens. The good fellow and a photographer at that (he understands a lot) passed the lens to the nearest SIGMA center. After ten days of investigation the SIGMA engineers come out with:

“We found no fault in the lens.”

“We can only adjust the AF system.”

“Any other copy of the lens would be exactly the same.”

Hearing the above I left the faulty SIGMA 8-16/4.5-5.6 and took my money back.

Chapter Three: CONCLUSION

To cut the long story short, rather than repeating the headlines let’s just check the score of the lens.

Optical Quality: 33 out of 63 equals 52%.

Mechanical quality: 15 out of 26 equals 58%.

Now it is a matter of the individual preferences but if you ask me if a USD one thou is the right price for a lens of the above score I would definitely say NO.