Quote Originally Posted by HDNitehawk View Post
Buy my 300mm F/2.8 L IS (version I) (or some other persons)
It will out perform any of the lenses you listed.
It performs well with a 1.4x.
To me it is not much different than carrying the 70-200mm F/2.8.
It would be as portable as the new 400mm DO at about 60% of the money.
I hadn't focused on the Mk I, but have been looking at the Mk II. The MK I seems to take a reasonable hit with the 2x TC to get up to 600 mm and is running $3-3.5K on ebay. But, it'll stay in the discussion. I've very much considered the MK II. I've seen refurbs for sale at ~$5,700. The benefit to me is less about super tele reach, but more the f/2.8 @ 300 mm.

Quote Originally Posted by neuroanatomist View Post
.....100-400 II + 1.4xIII. You lose 2/3 of a stop compared to the Sigma 150-600...... if the IQ was not too different.
Exactly. This option is tempting me and almost caused me to cancel my Sigma pre-order. But, I think there is a pretty reasonable chance that the 150-600S does have better IQ at 560 mm and will have a 2/3 stop advantage. At that point, it would be IQ vs size/weight.

Quote Originally Posted by Joel Eade View Post
What is the subject matter that interests you in a super-tele? In my case, birds. .......I would recommend you get the best glass in whatever focal length you thinks suits you even if you have to save a while....you won't be sorry!
Thanks Joel. For what I shoot now, this lens will mostly be for birds. But most of the birds will be through travel or from a kayak. For example:
  • In December I will have a chance to shoot eagles in Idaho when I visit family (annual event).
  • January I will be down in Orlando for a week with a good amount of time for me to maybe chase birds there (this looks like it may become an annual event. My wife has a conference she likes to attend and, with my new job, I can work from there).
  • I will be shooting eagles on the Merrimack (Mass).
  • GBH rookeries in Spring
  • Loons from a kayak
  • Other birds while kayaking.


Travel and shots from a kayak will be the majority of my use. Not the classic Big White on a tripod. I am considering something like your back yard set up. But I am not there yet (I really do want some cardinals). While I know big whites can travel, I have to consider the rest of my kit in that the 24-70 and 70-200 will likely also be coming along, maybe with a few other specialty lenses.

My biggest issue with the 100-400 II is that I already own the 100-400 MK 1 and know I would like a more reach. Granted, I think that is always the case. Also, when I can fill the frame, really the MK 1 is a good lens. My issues have been that I am usually cropping. I did try the MK 1 with a 1.4TC. I have seen good images taken with that combo, but lets just say I am not sure I have the sharpest MK1.

So, that is my specific need.

But, I am really marveling at the influx of good options. There will always be the 800 f/5.6, 500/600 f/4s for the best IQ. But, beneath that, there seem to be an increasing number of good options. While this doesn't get the reach beyond 400 mm (ff equiv) I want, I have also marveled at the optics/cost of the 55-250 STM. But a potential great lens for those not wanting to invest in L glass.