Panoramic Heads by Nodal Ninja

Tuesday, March 2, 2010

Sigma 30mm f/1.4 Review

(updated 4/27/10 with Infrared information)

The Sigma 30mm f/1.4 is an interesting character.  It is the only lens of its kind for any of the common mounts.  For APS-C sensors it is very close to a standard lens with a focal length about the same as the sensor diagonal (28mm), and the f/1.4 max aperture is handy for those low light situations.

Construction quality is good.  On the Pentax mount it uses the screw drive focus instead of HSM used for other mounts.  It has a nice heft to it and everything works smoothly.

Size wise, it is a fairly large prime, but smaller than most zooms.  It has about the same physical dimensions as the kit 18-55mm zoom lens, but weighs significantly more.  However, given the f/1.4 aperture it is reasonably sized, and is noticeably smaller and lighter than most mid-level standard zooms like the Pentax DA 16-45m 17-70, or Sigma 17-70.  It is more compact than many of Sigma's other primes (like the 28mm f/1.8 and 50mm f/1.4) or zooms, as it doesn't use their standard 77mm filter thread body, and instead uses a 62mm thread size.  It doesn't have all the wasted space in the lens body like Sigma's other lenses.

Handling

The lens is a joy to use.  Focus is quick and accurate with my K-7 with no focus adjustment.  It locks quickly and accurately in all lighting situations.  Occasionally it will focus confirm on an object completely out of focus, but this behavior can happen with any lens, and it is easily visible in the viewfinder.  Usually this only happens with a strong back light or low contrast object.  I usually just point the focus indicator to higher contrast edge or reduce the back light in the image and it focuses immediately.

My only complaint with the handling is the focus ring turns during auto focus operation.  The lens doesn't have manual override and it lacks a switch on the lens to disengage the focus ring.  The user needs to be aware of this and never grip the focus ring tightly during operation.  Manual focus is well damped, but a tad light.  However, it is above average for an AF lens.

Performance

Optically this lens is bi-polar.  It has a fair amount of barrel distortion (1.7% barrel) for a standard field of view lens, that can easily be viewed in field situations with straight lines.  However, the lens has a strong emphasis on center sharpness that the design leaves the corners very weak at all apertures making the lens not so useful for architecture shots.  Performance at f/1.4 near the center of the frame is also excellent, with good contrast even wide open.
Mtf50Plot

There is a bit of focus shift at f/2 to f/4 or so and there is a bit of a trade off between corner sharpness and center sharpness depending on where you focus. The "Partway" graph shows best performance focus and was from a separate focus set as the center data. If you are using the 11 pt focus system, be sure to select the focus point closest to where you are focusing. Focus and recompose will give poor results near wide open with this lens due to the field curvature. The corners and extreme left and right borders are always soft and don't sharpen much beyond f/2.8.

Corner performance drops due to astigmatism and field curvature at f/1.4, but the lens is still usable at the corners for people and portraiture, and other work where high sharpness is not required, see the test picture of the cat with the eyes in the corner of the frame following the conclusion.

However, the images near the corners are not quite as pleasing, as the astigmatism leads to some less than pleasing blur and the chromatic aberration (CA) is higher near the corners, and the CA increases while stepped down.

LateralCA

Flare resistance is excellent.  In contra light (a strong light that is shining at the lens) the lens rarely produces any flare spots from internal elements or the aperture, and if it does they are faint octagons.  It also has little veiling glare, the reduction in contrast frequently seen in contra light. 

Specular highlights are pleasant, but octagon when stepped down. They are fairly uniform in most situations and don't have strong rings around the highlights. See some samples in following the conclusion.

The lens has a strong hot spot if standing in bright light while taking infrared pictures using a Hoya R72 filter (hood was attached). See sample in images following. It helps standing in a shaded area to kill off any flare causing the hot spot.

Conclusion

The Sigma 30mm f/1.4 is a unique beast.  It is the only lens of its aperture and focal length, and is relatively low price compared to similar offerings.  It is a full f/stop larger aperture than the SMC Pentax FA 35mm f/2, and significantly wider field of view.  It offers 1/2 an f/stop over the SMC Pentax FA 31 f/1.8 Limited, and Sigma 28mm f/1.8, and 2 f/stops over the SMC Pentax FA 28mm f/2.8, and none of these lenses surpasses the Sigma 30mm f/1.4 for center sharpness.

However, corner performance on the test charts is dismal, and it is unfortunate they don't improve much stepping down the aperture.  That being said, I find in real world applications I don't notice the corners being soft, as my subject matter is not usually architecture where the soft corners or barrel distortion become noticeable.

Strengths

  • General Purpose (standard field of view)
  • Available Light
  • Portraiture
  • Night (produces nice star bursts)

Weaknesses

  • Architecture
  • Cityscapes
  • Panoramas
  • Infrared
I think some other reviews are overly harsh on this lens, as they look primarily at the test chart data and don't show how the lens can be effectively used to produce great results.  The characteristics of this lens are much like the poorly reviewed SMCP FA* 24mm f/2, which has stunning results in the center, and so-so at the edges, but in the right hands it can deliver amazing photographs.

Let's face it: how many standard field of view lenses have an f/1.4 aperture for APS-C sensors?  None.  The SMC Pentax FA 31mm f/1.8 Limited is certainly an excellent lens, but costs nearly three times as much in the US and is 1/2 an f/stop smaller aperture.  So even with the weaknesses of the Sigma 30mm f/1.4, I recommend it as a great available light portraiture and all purpose lens.

Test Images

(click on image for full size)
Real world center performance at f/1.4
IMGP3071
f/1.4, 1/125, ISO 400, K-7

Real world center performance at f/1.4 (image 2)
IMGP3057
f/1.4, 1/80, ISO 400, K-7

Real world corner performance at f/1.4
IMGP3751
f/1.4, 1/250, ISO 100, K-7

Scene showing soft left and right edges when stopped down
IMGP2843
f/6.3, 10", ISO 100, K-7

Scene showing star bursts at f/5.6 (star bursts are natural, but image has other processing for curves, saturation, etc).
IMGP2863
f/5.6, 0.8", ISO 100, K-7

Specular Highlights f/1.4
IMGP2497

Specular Highlights f/2.8
IMGP2502

Center focus shot with distracting background at f/1.4
IMGP3768
f/1.4, 1/160, ISO 100, K-7

Center focus shot with distracting background at f/4
IMGP3770
f/4, 1/80, ISO 400, K-7

Infrared image showing hot-spot, Hoya R72 filter on lens.
ERIC1519
f/5.6, 5s, ISO 200, K-7

Infrared image without hot spot (was standing in the shade).
Swing
f/1.4, 1/30, ISO 3200, K-7 with Hoya R72, processed in camera

And a bunch more from my flickr photostream.

Sigma 30mm in the center with the Rokinon 85mm f/1.4 on the left and the SMCP A 50mm f/1.4 on the right. A great set of lenses for wedding photography.
IMGP3961

Wednesday, January 6, 2010

Metz 58 AF-1 Flash Update for Windows 7

The beautiful thing about the Metz 58 AF-1 flash is that you can do firmware updates via your computer's USB port. The downside is this doesn't work with a Mac, and it requires driver updates that don't work well with Windows 7. These directions detail how to install the drivers for Windows 7.

















UPDATE: Apparently the drivers can be auto updated if you have an internet connection and you have Windows 7 set to pull drivers from the internet.  The following directions would still work for a computer not connected to the internet.

Warning:  These instructions are not endorsed by Metz.  Proceed at your own risk.

The first step is to download the Metz update for your system from Metz: Metz 58 Firmware Update.
or Metz 48 Firmware Update

After that has completed, open the Windows executable.















Type the desired location and click "Unzip"











The screen should pop up with a confirmation:










Click OK and remove the batteries from your Metz flash and turn it off.  Attach it to your computers' USB port using a mini USB cable.  Windows will pop up with a message saying it found an unrecognized device.

An error pops up saying the device driver was not successfully installed, click here for details.  This is where the instructions differ significantly from what Metz provides for Windows XP or 2000.


Go to "Start"-> "Control Panels"
Click View Devices and Printers


















You will see a warning symbol under a device called "MB58 AF1 Pentax"


















Double click on the device and click the "hardware" tab.




















Make sure the device is highlighted and click "Properties".




















Click "Change Settings".




















Click "Update Driver"



















Click "Browse My Computer for driver software"



















Browse to the files you just unzipped, in the sub directory "58AF1 Pentax V1.1 GB\Driver"

It should say it is installing device and it was successfully installed, but there is a second device that needs to be installed as well.




















Close ALL windows.  I found I must close the control panel for view devices and printers or information wouldn't refresh correctly.

Open the Control Panel, open the View Devices and Printers control panel again.  In the View Devices and Printers window, double click on the MB58 AF1 Pentax device again:

It still has a warning symbol on part of the device




















Highlight the device with the warning, and click Properties (it doesn't show on mine as I can't do a fresh install since I already installed it once).




















Repeat the procedure above for the second device with the warning. Click on "Properties", and then click on "Change Settings" and then on the "Driver" Tab click "Update Driver" and browse to that same folder you did for the first part.

After the driver install is complete run the file:
In the C:\Users\Eric\AppData\Local\Temp\58AF1 Pentax V1.1 GB\FirmwareUpdateGB.exe
(where ever you unzipped the files, in the folder \58AF1 Pentax V1.1 GB\)















After that there is a two part process.  Downloading the data and updating the flash.  It might take 1 minute total.  Halfway through a window pops up saying "All datas are download successfully".  The bad grammar adds to the experience :)  Wait a minute or two to be safe once everything is done and unplug the flash.  Put the batteries back in and start it.  It should say version 1.1 when it boots.

I hope that helps someone!

Eric

Monday, January 4, 2010

WD My Book Studio Review

IMGP1898
WD My Book Studio
My review for this week is the Western Digital My Book Studio hard disk drive.  Featuring Firewire 800 and USB 2.0 interfaces, an E-Ink display for volume information, WD GreenPower HDD for power and heat savings, and all packaged in an elegant silver box.

Initial impressions of the drive:
1. Product lighter and smaller than expected.  Bottom Heavy.
2. E-Ink display still showed Videos 09, at first I thought it was a sticker to protect the screen.  Neat to see it holds state that long
3. Includes Firewire 800, 800-400 adapter, USB cable standard mini type, and small AC power adapter, but the plug is part of the adapter so it takes more surge protector space.
4. Looks aluminum but it is plastic.
5. AC Power Adapter supplemental instructions had many typos and were poorly translated.

Setting up the Drive
Easy, but not totally as per the directions.  The software tried to get me to use it to backup using there software instead of time machine at first.  Don't recall exactly what I did to make it work, I don't think I had to do anything.  The first thing to do is install the WD SmartWare software.  There is no getting rid of the icon on the desktop or opting out of using the software.  However, the drive seems reliable with no random disconnects as of yet.  My other external HDD would randomly disconnect.

Once the software is installed be sure to open the SmartWare program and go to "Settings" -> "Setup my Software" -> "Preferences" -> uncheck "Open WD SmartWare when Drive is Connected" or it will get really annoying every time the Time Machine backup runs and it opens the WD SmartWare window saying it is categorizing your files.

Run "System Preferences" -> "Time Machine" and select the volume mounted on the desktop as the time machine backup.  There is two volumes, one for the WD SmartWare and one for My Book (or whatever your volume is named).  Be sure to select the actual hard drive, My Book.

Right click on the WD SmartWare CD icon (which WD claims is a "virtual CD", or VCD) and eject it.  It might come back later though.  If it does, you are stuck with the extra icon until WD decides to release the update for My Book users.

Using the Drive
My 260 GB Time Machine full backup took maybe 2 hours, which is fairly reasonable.  This wasn't as fast as the peak performance of the drive, but I was doing other operations on the computer while it was running.  I decided to test out the Firewire 800 v. USB 2.0 performance to see if it was worthwhile to use the FW800, and the answer is most definitely "YES!".

FW800 Write Performance
Large File: 1,493,332,688 bytes
Transfer Time: 23 seconds
Transfer Rate: 62 MB/s

Medium Files: 4,715,060,789 bytes
385 items
Transfer Time: 69 seconds
Transfer Rate: 65 MB/s

USB2.0 Write Performance
Large File: 1,493,332,688 bytes
Transfer Time: 42 seconds
Transfer Rate: 34 MB/s

Medium Files: 4,715,060,789 bytes
385 items
Transfer Time: 130 seconds
Transfer Rate: 35 MB/s

After using the drive for a while, there were a few things I noticed:
1: The drive automatically mounts when firewire plugged in
2: The WD SmartWare is too intrusive
3: The E-Ink screen is hard to read in a dark corner
4: The drive is quiet but audible.  No jet engine taking off, but it makes your standard hard drive noises.  Enclosure well ventilated, with vents on three edges.
5: Nice that disk utilization and label remains after you shut off the power

Verdict
A nice external hard drive with some unique features, but the intrusive software might bother some users.  There aren't a lot of choices for Firewire 800 drives for mac users, and this is certainly a sound offering with about twice the performance of the USB 2.0 connection.  For the 1 TB FW800 drives, the LaCie d2 Quadra might also be worth a look.