Nikon Reviews in a Nutshell

Sigma APO HSM 100-300 mm f/4D IF EX

In spite of the widespread clamor among Nikon wildlife photographers for semi professional long lenses in the USD 1.000-3.000 price bracket, the mayor manufacturers are still unwilling to listen.
A sad example is the recent discontinuation of the excellent APO HSM 100-300 mm f/4D EX Sigma, which - at the time of writing - continues to sell for about USD 1.200 on Amazon. For current pricing, click here, for my review here.

In combination with the APO 1.4x EX Sigma tele-converter (± USD 235) it turns into a 420 mm lens on FX, with a 630 mm equivalent FoV on APS-C (DX) cameras, maintaining full AF capability at the loss of only one stop (f/4 becomes f/5.6).
In line with the general trend to introduce ever faster long lenses combined with VR/OS, which also adds considerably to price, Sigma's official recommendation for replacement is the APO HSM 120-300 mm f/2.8 EX OS.

However, given this lens' MSRP of USD 4.700, such a so-called "recommendation" is outright preposterous.
That said - unlike most other Sigmas - this lens does not only autofocus with the 1.4x EX teleconverter, but also with the 2x EX TC at the loss of two stops (f/2.8 becomes f/5.6), which would make it an interesting option, if it were not for its elevated price.

It is extremely unfortunate that the big manufacturers keep churning out very expensive f/2.8 to f/4 long zooms and primes, instead of offering Nikon wildlife lovers quality 400 and 500 mm f/5.6 lenses that are more or less affordable.
Canon, at least, gives its users two lenses in this focal- and price range, the EF 400 mm f/5.6 L USM and the EF 100-400 f/4.5-5.6 L IS USM.
The first streets for ± USD 1.350, the second for ± USD 1.700 and both get high notes at photozone.de, especially the fixed focal.
It would be really nice if DxO Mark would test these types of lenses too, but apparently they are too much of a niche to be worth considering.

...

100-300 f/4D Sigma @ 300 mm. D200, 1/350 - f/6.3 - ISO 400 - handheld.

What are the alternatives we're left with?
With the 100-300 f/4 Sigma virtually out of the way, Nikon now has the 200-mm-plus constant aperture mid-price segment to its own, with the outstanding AF-S 300 mm. f/4D IF-ED Nikkor (± USD 1.500).
There is nothing else left for us to choose from in the 1-3K price bracket, and if you are in the market, you'd better hurry if you want a fairly cheap constant aperture IF lens other than Nikkor in this focal range.

After that it's variable aperture, such as the average AF VR 80-400 mm f/4.5-5.6D ED Nikkor (± USD 1.700), the mediocre and heavy 50-500 mm f/4.5-6.3 "Bigma" (± USD 1.700) or something in the "aficionado" segment, like the AF-S VR 70-300 mm f/4.5-5.6G IF-ED Nikkor (± USD 500).
Although many on the Flickr D90 group coincide that this lens is probably Nikon's best bang-for-the-buck in the category, none of these lenses are even close in IQ to the 100-300 f/4 Sigma or the 300 f/4 Nikkor.

The only lens that - according to the photozone.de user survey - may still be worth considering is the AF 200-500 mm f/5-6.3 SP Di Tamron (± USD 960), only slightly outscored in the user survey by the afore mentioned 80-400 mm Nikkor, which the site's expert review calls "a decent performer with a few glitches".
Meanwhile, an expert review on the same site concludes that the 200-500 mm Tamron is "an interesting representative of it's (rare) species" and that "the performance figures are generally on a very high level - very good between 200-400 mm and still good to very good at 500 mm".

Read on at your own risk. Domestic trouble ahead.
I have been waiting forever to finally go FX with the next incarnation of the Nikon D700.
Unfortunately, the most serious downside to that upgrade is precisely long glass, practically forcing me to stick with the D200 for wildlife.
The only economical alternative for FX appears to be the Tamron, but I have only found tests of that lens on (Canon) APS-C cameras, where it is clearly outscored by the EF 400 mm f/5.6 L USM.
It is fair to assume that the Tamron's performance on FX will be even less flattering.

That leaves us with only a handful of wallet-splitting, bank-breaking, plastic-crunching alternatives:
1 - APO HSM 120-300 mm f/2.8 EX Sigma, MSRP: USD 4.700
2 - AF-S 200-400 mm f/4G ED VR II Nikkor, MSRP: USD 7.000
3 - AF-S 400 mm f/2.8G ED VR Nikkor, MSRP: USD 9.600
4 - APO HSM 500 mm f/4.5 EX Sigma, MSRP: USD 6.400
5 - AF-S 500 mm f/4G ED VR Nikkor, MSRP: USD 8.600
6 - AF-S 600 mm f/4G ED VR Nikkor, MSRP: USD 10.300
7 - APO HSM 800 mm f/5.6 EX Sigma, MSRP: USD 9.700
8 - APO HSM 300-800 mm f/5.6 EX Sigma, MSRP: USD 11.500

If the above are still not expensive enough for you to risk your relationship and if you also love to say "built like a tank", there is one last, say-it-all choice: Sigma's bazooka-like "Green Submarine".
The APO HSM 200-500 mm f/2.8 EX converts into 400-1000 mm f/5.6 thanks to its dedicated 2x TC, comes with its own battery pack and charger, weighs a mere 14,7 kg/32.4 lbs., and can be yours for the modest MSRP of only 38 Grover Clevelands.

Sigma's "Green Submarine": 200-500 mm. f/2.8

If your better half is cool with shelling out anything between the price of a second hand Chevrolet Spark to a new Audi TT Hatchback for a long lens, you truly are one happy camper.
For the rest of us poor SOBs, on the other hand, there is nothing left to do than urgently call upon Nikon, Sigma, Tamron and Tokina to come up with test-resistant 300 to 600 mm lenses for under 3K., or else risk divorce.
If you are also in dire need of an "affordable" lens in this focal range, join us at Facebook and Flickr, tell us what you want and how much you're willing to pay for it.

Note: All prices at time of writing. MSRP quoted from the Nikon and Sigma USA websites, ± prices quoted from Amazon.