Most photographers with really long lenses and top-line cameras (DSLRs) will tell you that you still need to get in closer to a bird, especially smaller species, to get a very good image quality.
We can look at what on the surface are two camera outfits that can zoom in very close...............
- The latest 'winner' in the superzoom race for long range is the Nikon P510. It has a zoom range to an amazing 1000mm. This camera costs under $500. and weighs 19.6 oz.
- To get that telephoto reach we could go to the Nikon D300S with the Nikon 600mm lens. With its sensor factor of 1.5 this gives a range (close to the P 510) of 900mm. This camera and lens outfit costs over $11,000.and weighs about 15 lbs.
The fact is that if you were to photograph a Robin which is 200ft away, neither camera is likely to give you a superb image quality. The DSLR will definitely do 'better', but that is a relative term. Both cameras should be supported by a tripod since at near-1000mm it is almost impossible to eliminate camera shake.
The Nikon D300S/600mm will do better because it has a bigger sensor, and that 600mm prime has very few compromises such as are inherent in the 'superzoom' lenses. And in this case the competing P 510 has no RAW capability.
But, and here is the biggie..................
If the DSLR is left shooting the Robin from 200ft and the person with the P 510 moves in to say 30ft, the gap between the quality of the images will narrow. And, that gap will narrow even more if the superzoom is backed off from 1000mm to perhaps about 500mm or less.
The Nikon 600mm just loves being at 600mm (it's all it has!) but superzooms drop off in quality the longer they go.
So, if you have a superzoom, and perhaps not the longest (unless you 'just' want an image) and are able to get close, you can get pretty good images................
- remember that photography is all about light, and the quality of light is what can make the difference between very good and superb images.
- whether using a DSLR or not, take care in holding and supporting your camera (and look into a tripod or monopod as an option for greater support)
- if you can, shoot RAW, but regardless, if you want better images you must invest time into image editing
I've seen superb bird images taken with superzooms, and on the other side I have seen very poor images from some very expensive gear. The common factor was the operator skills.
Don't assume that good (bird) photos will suddenly happen with the purchase of that 'better' superzoom or even with a high-end DSLR.
Paint artists don't produce masterpieces as a result of buying the latest-and-greatest brushes