Pentax DSLR : Pentax DA17-70 F4 AL [IF] SDM Review

Pentax SMC DA 17-70mm F4 AL [IF] SDM offers the most attractive combination of range, speed, technology and price - on paper at least. It is a dedicated APS-C format lens with a field-of-view equivalent to 26-107mm (full format).

The DA 17-70mm f/4 features the new near-silent Supersonic (ultrasonic) Dynamic Motor (SDM) AF. Unlike the DA* 16-50mm f/2.8 SDM it does not offer the old AF drive screw for legacy DSLR support but that's forgivable by now.

This lens is using KAF3 mount which means only can AF with SDM support body. With non-SDM body, only manual focus available.

Specifications

Image Circle	: APS-C
Focal Length	: 17-70mm
35mm Equivalent	: 25.5-105mm
Max Aperture	: F4
Min Aperture	: F22
Diaphragm Blades	: 7 Blades
Lens Construction	: 17 Elements in 12 Groups
Angle of View	: 79 to 23 degree
Focus Details	: Internal, SDM with quick-shift focus
Front Element Rotation	: No
Zoom System	: Rotary
Closest Focus	: 0.28m/0.92ft.
Magnification Ratio	: 0.31x/1:3.2
Filter Size	: 67mm
Dimensions	: 93.5mm x 75mm / 3.7 in. x 3.0 in.
Weight	: 485g / 17.1 oz (without hood)

1. Build Quality
The build quality is really good and comparable with DA* series. It feel very solid in my hand. The weight is on the average side which is not too heavy and not too light. Zoom ring is quite bigger(approx 35mm long) and it is very comfortable. It is also tight and this prevent lens slip off or extend when camera facing down.

This lens extend when zooming. It is feature with Internal Focus[IF] which means the lens not extend and rotating while focusing. The picture below show the size comparasion of the lens when extend.

2. AF Mechanism
AF respond is very fast as expected since it use SDM focusing. But the AF speed not much different with non-SDM lenses. About the accuracy, this lens focus accuracy is good but sometimes it give up when no proper contrast detect and need to refocus.

This lens also feature a quick-shift focusing mechanism means it can give you fully manual control and you can easily manual focusing without changing focusing mode.

During the focusing, this lens does not making any noise like screw dirven AF lenses. Thank you for the SDM feature which make this lens silent during focusing.


3. Image Quality(IQ)
IQ is comparable with DA* series. This lens reported use the same glass as the DA* series. Flare and CA control are very good and seems better than DA*16-50. This lens also quite good at macro at 70mm. Minimum focus 28cm at the whole facal range give this lens maximum magnification around 1:3.2 at 70mm. This sharpeness is good at whole range. Quite soft wide open at 70mm but good if increase 1 or 2 stop.

4. Distortion and Vignetting
Distortion is quite visible at 17mm but stil acceptable. At 24mm and above, distortion is nearly zero. At 17mm wide open, this lens show around -1EV vignetting but not really noticeble. It can be correct by using F5.6 and above.

5. Chromatic Abberations(CA)
This lens control CA quite well and it is acceptable. The weakest point is at 17mm which pronouced CA especially in wide open aperture. But it can be correct by step down one stop exposure. Beyond 24mm and above, the CA is very well control.

6. Conclusion
For overall this lens is very good for a daily use. The focal cover from 17mm to 70mm is very usefull for street shooting or travel.

Pros :
1. Better build quality, solid
2. Better CA control
3. Better accuracy
4. Fast respond and silent AF
5. IQ comparable with DA* series
6. Very good zoom ring

Cons :
1. Can only AF with SDM support body
2. Easy to give up(AF)
3. Max aperture F4
4. Price

7. Rating

1. Optical Quality	★★★★
2. Build Quality	★★★★☆
3. Value for Money	★★★☆

RECOMMENDED

Pentax DSLR : Tamron SP AF 17-35mm F2.8-4 Di LD Aspherical [IF] Review

This Tamron's ultra wide-angle zoom lens starts at 17mm when used with a conventional 35mm SLR camera. When mounted on an APS-size digital SLR camera, it provides a focal length coverage equivalent to a 28-55mm (on a 35mm format camera), covering the desirable wide-angle to standard range.

It has maximum aperture F2.8 at 17mm and F4.0 at 35mm. Being F2.8 at wide end is an advantage for this lens compare to other wide angle lenses. It has 77mm filter which is very usefull for a wide angle lens to prevent vignetting at wide end. The spherical front element will cause some flare but can be correct easily by using a petal type lens hood that come with the lens.

Specifications

Image Circle	: 35mm
Focal Length	: 17-35mm
35mm Equivalent	: 25.5-52.5mm
Max Aperture	: F2.8-4
Min Aperture	: F22
Diaphragm Blades	: 7 Blades
Lens Construction	: 14 elements in 11 groups
Angle of View	: 104 to 63 degrees
Focus Details	: Internal
Front Element Rotation	: No
Zoom System	: Rotary
Closest Focus	: 0.3m / 0.98 ft.
Magnification Ratio	: 0.19x / 1:5.4
Filter Size	: 77mm
Dimensions	: 86.5mm x 83.2mm / 3.4 in. x 3.3 in.
Weight	: 440g / 14.4 oz

1. Build Quality
The build quality is satisfied me and feel solid in my hands. The build seem better than other tamron lens and not feel plasticky. The weight and the size is quite acceptable for the wide angle lens. This lens come with a huge petal type 77mm hood to prevent flare.

This lens extend when zooming but it just extend around 1cm and not really noticable. This lens feature Internal Focus[IF] which prevent it extend or rotating while focusing. The picture below show the size comparasion of the lens when extend.

2. AF Mechanism
This lens AF is quite faster. The AF sound is a little bit noisy but still acceptable and not annoying me. The accuracy is good for a close range object at all focal length but sometimes it missfocus when the subject range is too far especially at 17mm and wide open.







3. Image Quality(IQ)
This lens is very sharp even at wide open and extreme sharp if you add 1 or 2 stop exposure. The center sharpness was really impressive but the corner sharpness is drop drastically but still acceptable.

Sharpness at 17mm F2.8 [Click for full resolution] Handheld 1/4s ISO400

4. Distortion and Vignetting
At 17mm, this lens show visible distortion but there is no distortion from 24mm and above.

Brickwall test at 17mm [Click for full resolution]

5. Chromatic Abberations(CA)

6. Conclusion
For the conclusion, overall I found that this lens is very worth for the money I paid. Here are some samples that I took with this lens. I will add some sharpness and resolution test in the future for reference.

7. Rating

1. Optical Quality	★★★★
2. Build Quality	★★★★
3. Value for Money	★★★★☆

HIGHLY RECOMMENDED

Pentax DSLR : Pentax K-X Brief Introduction

Pentax DSLR : Pentax K-X Info

Pentax has announced their new entry-level DSLR known as K-X on September 17, 2009. It has a lot of feature from the Pentax's current high-end DSLR, K-7. It used the same body used on the previous K-M model but with the latest Pentax's technology adopted from the K-7. It also features a live view mode and ability to shot 720p HD movie. Different from other pentax DSLR, it featured a new high resolution 12.4 megapixel CMOS image sensor from Sony.

There is something interesting about this new camera from Pentax. I available in a choice of colors. There is black and white plus limited edition of red and navy. Also there is another 100 choice of customize colors.

Here are some new additional features added in this K-7
• High resolution 12.4 megapixel CMOS image sensor features sensor-shift Shake Reduction.
• PENTAX PRIME II image processing engine.
• Large 2.7 inch LCD features Live View with contrast, phase difference, and Face Detection autofocus (up to 16 faces).
• Capture widescreen HD video in full 720p resolution (1280x720) at 24 FPS cinematic framerate.
• Highly compact DSLR body design allows for 1 handed operation and comfort when travelling.
• Powerful automatic modes, including PENTAX Auto Picture and scene modes.
• Creative processing and filter modes produce high quality finished images.
• True HDR image capture blends 3 bracketed images into a single picture with outstanding shadow, highlight, and detail.
• Fast 4.7 FPS capture speed and 1/6000 second maximum shutter speeds.
• Responsive 11 point wide angle SAFOX VIII autofocus system focuses quickly and accurately.
• Capture up to 1900 shots with universally available, easy-to-find AA lithium batteries.
• Expanded ISO range covers sensitivities from 100-12800 for extreme low light photography.

Now Pentaxians or other photographers can have Pentax K-7 features in this new K-X with a smaller and lighter body, and more important with a very affordable price.

Pentax DSLR : Pentax K-7 Brochure

Pentax DSLR : R3-UT Wired/Wireless Remote Review

This is another accessories that I have in my bag. A wired and wireless remote for dslr. Since I am more into landscaping, I found that this remote is very usefull for me. Very convenience and easy to use.

Below are the specs of this remote :
• More than triple the operational range of other IR transmitters.
• Multiple compatibility - Nikon, Canon, Pentax and Samsung Cameras.
• Includes Cable Release for wired shutter release function.
• Can be used with B settings for convenient and accurate time exposure control.
• Battery power saving design - provides longer operation time.(battery is easy to replace)
• One center button fires the camera shutter.
• Supports instant and half shutter, AE/AF functions
• Bright white LED can also be used as a flashlight(both blinker and constant lighting modes)
• Maximum range up to 50m(Pentax, Samsung, Nikon) and 25m(Canon)
• 19g, 26mm X 88mm X 17mm

Pentax DSLR : Pentax K-7 Brief Introduction

Pentax DSLR : Pentax K-7 Info

It has been around a month after Pentax launched their new semi-pro DSLR know as K-7 on May 21, 2009. It is the first Pentax DSLR to have a magnesium-alloy body making it smaller than the K20D it replaces, while still offering reassuring build quality. The body is weather sealed and features a 920,000 dot LCD and 100% viewfinder and the ability to shoot 720p HD movies. Like the models before it, the K-7 has image stabilization built into the body, stabilizing all lenses. It offers the high level of exterior control you'd expect on a camera at this level and its operation can be customized to a high degree.

Here are some new additional features added in this K-7
• 720p/1080i HD video recording
• Smaller magnesium/steel alloy body
• Revised viewfinder (less magnified but with greater coverage)
• Updated sensor with four-channel readout
• 3.0" VGA (920,000 dot) LCD
• New shutter mechanism with 1/8000th shutter speed
• Faster continuous shooting (up to 5.2 fps)
• 77 segment exposure metering sensor
• Revised autofocus algorithms
• AF illumination lamp
• New dust removal system
• HDMI output
• New dedicated ISO button
• Adjustable dynamic range highlight and shadow correction
• Three-shot in-camera HDR capture
• Electronic level indicator
• Composition adjustment (Uses the SR system to reposition the sensor to fine-tune composition)
• Distortion and chromatic aberration correction for DA and DFA lenses (also available in RAW conversion)

What I really likes about the features are in body distortion and CA correction, electronic level indicator, AF assist lamp, 3" VGA 9200000 dots LCD, HD video recording and 100% coverage of viewfinder. Other than that, I am not really interested.

The body design is more to entry level design with some missing button and I dont really like the design and the smaller size. I more prefer the larger size with solid build and higher density.