SUMMARY
To sum it up, I believe the new SP 150-600mm Generation 2 or simply G2 is a very significant upgrade over the first generation. The following are my observations in my field test using the lens extensively handheld for several days in an actual Bird Photography race and also in a post event birding tour in the mountains and forests of Palawan.
1. It is definitely sharper as a result because of the upgraded optical performance which means the lens has a higher resolution and more contrast to produce images with great clarity in details.
2. Lens sharpness makes long distance captures usable because details are decent enough despite the distance where aggressive cropping is necessary. This is very common practice in bird photography as the birds are not going to stay in-front of you for close up portraits.
3. The AF System is substantially faster and more accurate. Focusing in low light is definitely a lot quicker faster too. AF works even at F/9.0 using a 1.4X Teleconverter. This is the upgrade that I noticed immediately in my earlier field tests. Birds-in-flight photography is no longer a big challenge for me with this new AF capability.
4. The G2 is no longer susceptible to Chromatic Aberration, Ghosting and flare even when shooting against the light. Shooting against the light is no longer a big problem.
5. Boheh is also softer and more pleasing to the eyes. The lens also creates more accurate colors. It is very useful in creating bird images with accurate plumage colors which is very important in Natural History Photography.
6. A new feature I found very useful during treks is the FLEX ZOOM LOCK mechanism which quickly locks or unlocks the zoom at any position by sliding the zoom ring. Very convenient as we start trekking where I always lock the lens at 150mm to shorten the barrel. A lot easier to walk without the long dangling lens at your side. No more lens creep too.
7. VC (Vibration Control) is more effective and powerful. I was able to create very sharp images at 1/40th sec. equivalent to 4.5 stops of light in a moving paddle boat with two other photographers scrambling to create their images. Proves that VC works very well in low light situations. Very big advantage for Bird Photographers because inadequate light is the norm in forest birding, our favorite birding habitat.
Final verdict, the new Tamron SP 150-600mm G2 is significantly better than the older model in many ways. It is well worth the upgrade and is highly recommended.
