Tokina 12-24mm f/4 AT-X AF Pro DX
Nikon 12-24mm f/4 G AF-S ED
Nikon 20mm f/2.8 MF AI-S
Technical Specifications of All Lenses:
|
|
Sigma 10-20mm f/4-5.6 D EX DC HSM |
Tokina 12-24mm f/4 AT-X AF Pro DX |
Nikon 12-24mm f/4 G ED-IF AF-S DX |
Nikon 20mm f/2.8 MF AI-S |
|
Filter Size: |
77mm |
77mm |
77mm |
62mm |
|
|
4-22 |
4-22 |
4-22 |
2.8-22 |
|
Minimum Focus Distance: |
24 cm (9.4”) |
30 cm (11.8”) |
30 cm (11.8”) |
25cm (9.8”) |
|
Magnification: |
1:6.7 |
1:8.3 |
1:8.3 |
1:8.3 |
|
Angle of View: |
102.4 - 63.8° |
99° - 61° |
99° - 61° |
94° |
|
Groups/Elements: |
10/14 |
11/13 |
7/11 |
9/12 |
|
Number of Aperture Blades: |
6 |
9 |
7 |
7 |
|
Length: |
81mm (3.2”) |
90mm (3.5”) |
90mm (3.5”) |
42.5mm (1.7”) |
|
Maximum Diameter: |
83.5mm (3.3”) |
84mm (3.3”) |
82.5mm (3.2”) |
65mm (2.6”) |
|
Non Rotating Front Lens Element: |
+ |
+ |
+ |
+ |
|
Internal Focus: |
+ |
+ |
+ |
- |
|
Internal Zoom: |
- |
+ |
+ |
N.A. |
|
|
- |
- |
- |
+ |
|
Weight: |
470g (1.0 lb) |
570 g (1.2 lb) |
485 g (1.1 lb) |
269g (0.6 lb) |
Introduction:
Demand for the ultra wide angle to wide angle zooms on the market for the small sized sensor SLR cameras has induced the production of the models at this range. Most of these lenses are DX or DC type that can only be used on the APS-C sized sensor cameras at full range.
For a digital Nikon SLR user, the choices can be narrowed between 3 models: Sigma 10-20mm f/4-5.6 D EX DC HSM , Tokina 12-24mm f/4 AT-X AF Pro DX and Nikon 12-24mm f/4 G AF-S ED.
I have included the manual focus Nikon 20mm f/2.8 Ai-S (produced in 1984) to the test because I want to see if the modern ultra wide angle zooms can beat this classic lens.
On a digital Nikon body with a 1.5 crop factor these lenses becomes 15-30mm, 18-36mm and 30mm respectively.
Please keep in mind that this test can not be taken as a definite conclusion just because I have tested only one lens from the each brand. Since I knew (from my previous experiences) that there may be sample to sample variation even on the lenses from the same production batch, making this test with other samples may vary the results.
Test Procedure:
For all the shots a Nikon D200 camera body attached with the Nikon MC-30 cable release were used. Camera was resting on a Benbo B1 tripod. All attempts were make to prevent the camera shake. A standard test target were used for the shots.
Camera modes were as follows: ISO: 100, WB: 5000K, JPEG Fine, Single Shot, AF-On, Mode: A, Matrix metering. Before every shot AF were carefully monitored for the focus shifts. If any shifts occured then AF were initiated again.
First View:
All the lenses handle very well on a Nikon D200 body. However the most balanced one was the Tokina because of its weight and length.
Both Nikon and Sigma zooms have inside the lens AF motors. Thus, the AF operation is very quiet on these lenses. Since, the AF/MF ring doesn’t have much turn because of the short focusing range, in my opinion AF-S or HSM is not a necessity at these focal lengths. I have noticed that being a non HSM or AF-S lens Tokina focuses nearly as fast as the others. Being a little noisier than the other zooms on the test Tokina is not a noisy lens as well. I love the focus clutch mechanism on the Tokina. By pulling the manual focus ring you can instantly reach the MF mode. You don’t have to change the mode on the camera body once you change it on the lens. Since Sigma and Nikon zooms have the HSM and AF-S motors you may always manually focus the lens by the focusing ring. You may manually fine tune your AF once the lens focuses on the target.
All the lenses have non rotating front lens elements. So using graduated and polarizer filters are not an issue. I have tested thin and thick polarizers on the Tokina at its 12mm setting and thick polarizers do vignette on the corners. I suggest you to use thin ones like the Hoya Pro1 series of polarizers. I love the paint finish on the outer barrel of the Tokina and Nikon. Since Sigma has an appealing paint it seemed to me less durable. Every lens has good grippable focus and zoom rings. The most solid feeling zoom lens on the hand is Tokina.
The photo on the below shows the front lens elements and coatings of the zooms. Color of the coatings seems different for the 3 zoom lenses.
Focusing distance indications are shown under a transparent plastic window for the 3 zooms. I have set all the lenses to their minimum focus distances before the shot on the below.
On the manual focus Nikon 20mm f/2.8 Ai-S focusing indication is not hidden under a plastic. I love the retro depth of field indicator on this lens. Each color corresponds a different aperture setting.
Tokina and Nikon zooms doesn’t change their physical length while focusing or zooming. Since Sigma has an internal focus mechanism this lens changes its physical length while zooming (note the small extension of the front element).
AF Accuracy:
While making AF on the test target I have noticed that sometimes Nikon zoom does not focus properly (before the tests I have encountered exactly the same problem with another Nikon 12-24mm zoom sample). On the other zooms AF operation is more reliable.
Resolution and Chromatic Aberration (CA):
Chromatic aberration is caused by the camera lens not focusing different wavelengths of light onto the exact same focal plane. In digital cameras micro lenses in front of the digital sensors (CCD or CMOS) may cause this problem as well. Resolution can be reffered as the sharpness or the ability of a lens to show the details of a scene.
Resolution of all the lenses in the test were generally well. All of them produced acceptable results. Sigma’s weakest point shows itself at its closest focusing range on the corners.
I have made different tests using the three zooms at their 12mm and all 4 lenses at the 20mm focal length settings. I have tried 2 different apertures: wide open and f/11. Wide open is one of the weakest point of nearly all modern zooms and we usually use this setting especially in low light handhold situations. f/11 is generally known as the aperture setting that these kind of zooms can perform at their best.
Photo on the below shows the test area with the lenses at their 12mm settings and white rectangles shows the cropped areas (360x250 px).
Now lets check the lenses at their 12mm settings. The test photos on the below clearly indicates that the results are different at f/4 (wide open). Tokina is sharpest followed by Sigma and Nikon. However CA (purple) becomes an issue on the corner and extreme corner samples of Tokina lens. Nikon and Sigma zooms showed some CA on the extreme corners (purple) as well.
When stopped down to f/11 resolution characteristics changed a little. Sigma is slightly sharper at this aperture setting at 12mm while it is very difficult to distinguish Tokina from Nikon. At this setting CA is better controlled by the Tokina than wide open. But it seemed to me that it is still higher than Sigma and Nikon.
Photo on the below shows the test area with the lenses at their 20mm settings and white rectangles shows the cropped areas (360x250 px).
For the 20mm setting I have added the results of the Nikon 20mm f/2.8 MF Ai-S to the sample images. At the f/4 aperture settings of the lenses, resolution results of the Tokina is very close to Nikon 20mm f/2.8 MF Ai-S. These two lenses are slightly sharper then the other two. Especially extreme corner sharpness of the Tokina is noticeably better. But corner sharpness of Nikon 20mm and Sigma is slightly better than others. Tokina still suffers from CA at 20mm wide open but CA is less visible at this focal length setting.
Stopping down to f/11 at the 20mm setting shines the Tokina. Its center and extreme corner sharpness is better than the other 3 at this setting. CA is nearly not an issue at this setting as well. The resolution and CA characteristics of the lenses other than Tokina are very close to each other.
For the close focusing corner performance I have used a little bell. All the lenses were set at their f/8. I have compared the 12mm setting, and added Nikon 20mm f/2.8 MF Ai-S to the test to see its performance. Since this lens has the Close Range Correction (CRC) mechanism of Nikon it is supposed to show equally well optical performance at its closest focusing range as at infinity. CRC can also be called as floating lens element mechanism on the other brands. Bell test gives us information about Bokeh and CA as well. On the below I have included a shot taken with the Sigma at its 10mm setting to show the different view angle of 10mm.
You can check the different view angles of 10mm and 12mm, and 20mm and 24mm from the photos on the below.
Bokeh:
Bokeh is the aesthetic quality (or pleasant look) of the out of focus (blur) areas. The word ‘bokeh’ is derived from the Japanese word ‘boke’ (pronounced as bo-keh) which means fuzziness. Bokeh is affected by the focusing distance, optical design and number and shape of the aperture blades of a lens. My out of focus area shots have shown that Nikon 20mm f/2.8 MF Ai-S lens produce the most pleasant Bokeh’s. This lens is followed by Tokina and Nikon zooms. The less pleasant Bokeh were produced by Sigma zoom.
Contrast:
Nikon lenses produced nearly the same contrats values. Nikon 20mm f/2.8 MF Ai-S have shown slightly less saturated colors. Their results were slightly more contrast than the other lenses. Tokina were the second next to the Nikon’s in terms of contrast. Color rendition is very close to Nikon’s as well. Sigma produces the less pleasant colors (a little on the unsaturated side) and slightly less contrast than the others.
Vignetting:
My sky test shots have shown that Sigma lens has slight vignetting on the corners. On the other lenses it is very difficult to detect vignetting.
Distortion:
Distortion of the Sigma at 10mm setting was unfavorable for me. Its correction with the Photoshop is difficult because of non linear characteristics. At the 12mm setting Sigma showed less distortion. Distortion characteristics of the Tokina and Nikon zooms were near equal at this setting. At 20mm distortion were less evident for all lenses.
CONCLUSION:
Modern ultra wide angle to wide angle zooms on the test are capable of producing high quality images. They cannot beat a classic Nikon 20mm f/2.8 Ai-S if we compare every aspect other than resolution. For the resolution tests it is easy to say that Tokina at its 20mm setting can beat the Nikon 20mm f/2.8 MF Ai-S on the extreme corners and can compete well on the corner and center resolution at the tested aperture settings.
While overall contrast and saturation is less pleasant with the Sigma, Sigma offers slightly better resolution at its 12mm setting at f/11. Close range corner sharpness is unacceptable with the Sigma as well.
In terms of resolution Tokina outperforms other zooms at 12mm f/4 and 20mm f/4 settings. CA values of Tokina sometimes make me wonder. But if you shoot RAW and use CA correction in photoshop, CA wouldn’t be an issue.
Nikon zoom can compete but cannot outperform the others in terms of resolution. Its overall performance is close to Tokina. However Tokina is better at the corner and extreme corner sharpness. Nikon is slightly better than Tokina in the contrast and CA areas.
Finally I can say that if you have much money to spend on a super wide to wide angle zoom for the DX type and love to have a lens bearing the Nikon name then go with the Nikon. But if you think twice you may find yourself choosing between Tokina and Sigma. Both of these lenses are great competitors. They have equal or even better resolution than the Nikon zoom.
If you like to experiment fantastic zoom ranges like 10mm and don’t want to handle CA than go with the Sigma, if you need a more durable lens with equally well sharpness at the whole aperture and zoom settings on the whole focus area and if you can handle the CA in Photoshop than go with the Tokina. Without the CA factor Tokina is a beauty in all the ways. An idiom in Turkish came to my mind right here: Every beauty has an imperfection.
Photographs, Turkish and English Text by Baybars SAĞLAMTİMUR
Tüm Hakları Saklıdır © All Rights Reserved www.fotoritim.com Sitesinde Bulunan Yazılı ve Görsel Eserlerin Bütün Hakları ve Sorumluluğu Eser Sahiplerine Aittir. All Images and Text Published in www.fotoritim.com are Copyright © Protected by The Author, All Rights Reserved. Use By Author Permission Only.
Thanks!
hmm.. do you think AF is really needed when working that wide? Thanks!
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