1 ACCEPTED SOLUTION
@ebiggs1 wrote:celson,
I personally have all the combinations that I suggested. I have used all the combinations I suggested . This is unlike some folks that recommend gear, I have actually used it.
Either the ef 300mm f4 prime or the ef 400mm f5.6 prime is going to be sharper than the new 100-400mm zoom. Either will be much better than the older version of that zoom. This will become more apparent as you crop or enlarge that perfect shot. Especially in printing if you so desire. If all you intend is showing off on the web, this is not so important.
If you think IS is a worthwhile feature for you I have no doubt the ef 300mm f4L IS USM and 1.4x converter is the way to go. It offers the distinct advantage to use the 300mm as is, if needed.
I will add one more thought and a suggestion. It is what I would personally do not considering anything you have said.
I would opt for the Tamron SP 150-600mm f/5-6.3 Di VC USD Lens for Canon. It is selling right at a grand right now. It is an unbelievable lens for the money. There is a SIgma model that is very simular but lacks any weather proofing which the Tamron has. But it is the Sigma 150-600mm f/5-6.3 DG OS HSM Contemporary Lens for Canon EF. Your choice as they are nealy twins in IQ.
Perhaps buying one of those lenses would leave enough money left over for a Canon EOS 80D DSLR Camera ($1200).
Hmmmmm...?
I've never used the Tamron or any of those primes, but I do endorse Ernie's suggestion that a new camera may do you more good than a major lens upgrade. On an organized safari you'll be able to use a tripod sometimes (assuming you have room enough to bring it along) and sometimes not. And a very long lens is very difficult to hand-hold on a crop-frame camera. I might be inclined to combine Ernie's suggestions and get the 1.4 TC (for your 70-200) and a new 80D or 7D2. Just a thought to confuse you further.
BTW, you might want to check the archives. I believe we had a lonnng discussion on the tradeoff betsween various teleconverters and various lenses sometime last year.
"... leaning towards new 80D and the Tamron 150-600."
Outstanding choice. The 80D as Robert from Boston indicated will blow the doors off your 40D. Most of the time lenses top the trade up or upgrade choices. But in your case an upgraded camera will help in many ways.
If you buy the big Tammy, you won't let it go.
@celson wrote:Thanks to all for thoughts...still doing my homework, but leaning towards new 80D and the Tamron 150-600.
Be very careful!!! The Tamron 150-600 has had focus issues with newer Canon cameras. The lenses had to be sent back to Tamron for a firmware update. Since the 80D is so new, who knows how it will work.
Also, it performs well on fat pixels of full frame cameras, but, not so well on with the higher pixel density of the newer crop sensor cameras.
The Tamron 150-600 would probably be ok, with your 40D since at 10 megapixels it has relatively large pixels.
Edit: Evidently there is no way to know if your lens was built with the new or old firmware. Supposedly from Tamron Technical Support. - 'Thank you for contacting Tamron. We do have an update for this lens that should help with autofocus all around. Unfortunately I don't have a specific serial number range for which lenses were updated. Your serial number is early in the series so this was most likely not updated. If you would like to send the lens in for the update please complete the attached service form and send the lens to our address at the bottom of the form. Please include your warranty confirmation number or a copy of your receipt.'
celson,
"... leaning towards new 80D and the Tamron 150-600." 
Here again I can only repeat what already I told you.
"I personally have all the combinations that I suggested. I have used all the combinations I suggested. This is unlike some folks that recommend, (or don't in this case) gear, I have actually used it."
DXO is highly disregarded by a lot of people, including me. So take it with a grain of salt. There was/is/ maybe a focus issue with the early Tamrons. But it affected the AI-Servo tracking ability. Neither of the two Tamron 150-600's I own exhibit this. Possibly I am just lucky but both were early models. Now Tamron has many thousands sold. Buy the lens from a good retailer like BH Photo or Adorama, Roberts Camera, Best Buy, etc. Matter of fact get the camera from one of these retailers. Or possibly form a local camera store that will let you play with the gear before you buy it.
Both shot on a crop camera. 600mm and 150mm.
Another point to remember in this decision, we are comparing this lens to lenses like the ef 100-400mm. Now the older 100-400mm is not in the same class as the Tamron which has far more updated optics. The Tamron is very sharp when compared like-for-like on cameras like EOS 80D. Plus the 100-400mm (new or old) doesn't have 500mm or 600mm at all!
We are not comparing it to lenses like the EF 600mm f4L whcih is 10 times more expensive. 
Maybe the ef 70-200mm f2.8L plus the 1.4x converter has better IQ but it won't have 500mm or 600mm either. I would offer one more suggestion. Get the lens well before you are to leave and need it. Learn it. Learn how it works. A big tele like this will require some learnig. You are talking some serious focal length here.
@ebiggs1 wrote:celson,
"... leaning towards new 80D and the Tamron 150-600."
Here again I can only repeat what already I told you.
"I personally have all the combinations that I suggested. I have used all the combinations I suggested. This is unlike some folks that recommend, (or don't in this case) gear, I have actually used it."
When did you get an 80D?
And I'm sorry neither of those images are particularly compelling.
"When did you get an 80D?"
Do you mistakenly think all my gear is indicateds in my sig? Well don't!
"And I'm sorry neither of those images are particularly compelling."
Odd reply coming from you, I must say. 
