Thursday, December 25, 2008

Pentax A* 300mm f2.8 Review

This is A* lens and it has been one of my "walk around" lenses ever since it has arrived in my posession. Believe it or not. This lens is addictive... I bought it as a demo item from US.


Construction
This lens is definitely short, sturdy and compact. It weighs 3.2 kg (apparently same as Fa 600mm f4 - how come??) and is attached with a tripod mount. There is a built-in lens hood, sliding back and forth with a small screw to lock in. Apparently over-use of the lens hood sliding back and forth would produce inevitable scratch to contribute paint loss...
It accompanies a aluminium silver box that I left it at home most of the time. A UV filter of 49mm can be inserted into a drawer close to lens mount - I had not yet bothered that at all.

Specifications
Mount: Bayonet Lens Construction: 8 groups 8 elements Angle of View: 8.2 degrees Diaphragm: Fully Automatic Min Aperture: 32 Min Focus Distance: 9.8 ft. Filter Diameter: 49mm (rear) Size Max Diameter Length: 5.2 x 9.3" Weight: 104.8 oz. Filter Size: 49mm (rear) Lens Hood: Built-in Lens Case: Trunk Case



Image Quality
With this lens, I have been using it in very dark environment. Aperture wide open has such a narrow depth of field, the subject needs to have the whole plane exactly parallel to the camera sensor in order to have sharp image all over. Using this lens wide open really requires a lot of technique as many of you maye be aware of how poor lighting can really give you little details in an image.
The images are sharp at all apertures (if i could focus accurately with my clumpsy hands). Image is really sharp after f4.
The bokeh quality does vary! Sometimes it shows up sigma style tubular matrix type bokeh sometimes it shows up 31mm style bokeh. It does not have 77mm bokeh CA - luckily. I personally like its bokeh most of the time.
Here are a few examples of images: (Forgive my lack of talent)

1/1000s f/3.5 at 300.0mm iso400 full exif
1/1000s f/4.0 at 300.0mm iso400 full exif
1/350s f/6.7 at 300.0mm iso400 full exif


1/180s f/4.0 at 300.0mm iso400 full exif


Handibility
Thanks to k10d VR feature, I could use this lens just with a monopod attached (with the tripod head loosely tightened). This definitely improves my ability to maneuvre camera together with the lens for various angles at ease. While using this lens to track agile birds, the monopod can be easily adjusted with its height and move around easily locating spot for the monopod. I know using this lens is quite tough but this has been quite an addictive thing for me now. While I hike, I could use the monopod as a stick to frighten away the snakes. Tom Lusk might get annoyed with this as he wanted me to photograph these snakes if I saw them...
Tripod is a no no for this lens. It kills the whole purpose of getting this lens as the weight is just unbearable. Hard to go through the bushes up and down with branches coming out of everywhere. The height adjustment of the tripod would take decades to accomplish and miss million of shots altogether.

Conclusion
Great lens (too bad that I already bought it; I had to like it anyway). The only issue would be its weight and price. I think manual focus is not that bad once you got the hang of it. If you can find this lens, I would go and get it to do protraits and other low light environment shots.
I am getting my Pentax Rear converter 2X very soon and hopefully it would give me 600mm f5.6 to play around with. I will post my humble opinions regarding this combination later on.


James

3 comments:

JM December 30, 2008 at 2:23 PM  

Fantastic bird shots!

roentarre December 31, 2008 at 11:03 PM  

Hi JM. Thanks for the drop in. This is a blog that I co-write with a friend of mine :)

Jon Woo January 1, 2009 at 9:06 AM  

wow! makes me extra proud to use pentax:D nice blog btw.