# RF 100-500mm vs EF 100-400mm II + EF-ER adapter



## AlanF (Sep 18, 2020)

It looks like I will be getting next week an R5. I do have two very good copies of the 100-400mm II + 1.4 and 2xTCIIIs and was intending to use one of those. I do have the opportunity of buying an RF 100-500mm, which is a serious outlay, especially with the high cost of RF extenders. I'd love to hear reports from those who have compared those lenses on the R5.


----------



## Bert63 (Sep 20, 2020)

I have the 100-400L II and the 1.4X III and have the R5 on order. I plan on using both side by side on the EOS-R and R5 and the 5D4. I’ll be happy to let you know of any impressions I have if you’re interested.

I’m actually looking forward to it because the 100-400L II and extender have been my go-to for years.

Once I see how things play out I’ll consider the 1.4X III. I’m thinking cropping or crop mode will be better considering the “f” penalty that comes when at 500mm you’re already sitting at f7.1, and that the full range of the lens isn’t available with the tele attached.


----------



## SteveC (Sep 20, 2020)

Bert63 said:


> I have the 100-400L II and the 1.4X III and have the R5 on order. I plan on using both side by side on the EOS-R and R5 and the 5D4. I’ll be happy to let you know of any impressions I have if you’re interested.
> 
> I’m actually looking forward to it because the 100-400L II and extender have been my go-to for years.
> 
> Once I see how things play out I’ll consider the 1.4X III. I’m thinking cropping or crop mode will be better considering the “f” penalty that comes when at 500mm you’re already sitting at f7.1, and that the full range of the lens isn’t available with the tele attached.



I have the 2.0x, I should try to nab the 1.4x. Especially since I found out not too long ago the 1.4 does better on the 100-400. I wonder if my brick and mortar still has that used one?


----------



## Bert63 (Sep 20, 2020)

SteveC said:


> I have the 2.0x, I should try to nab the 1.4x. Especially since I found out not too long ago the 1.4 does better on the 100-400. I wonder if my brick and mortar still has that used one?




I tried the 2.0 once and it didn't meet my expectations even under the calmest conditions imaginable - it was just too soft..

I found the 1.4 to be a near-equal to mounting the lens naked. Yes. I said mounting the lens naked.


----------



## AlanF (Sep 21, 2020)

Bert63 said:


> I tried the 2.0 once and it didn't meet my expectations even under the calmest conditions imaginable - it was just too soft..
> 
> I found the 1.4 to be a near-equal to mounting the lens naked. Yes. I said mounting the lens naked.


You or the lens?


----------



## Bert63 (Sep 21, 2020)

AlanF said:


> You or the lens?




The lens. Trust me, you don’t what to see what cannot be unseen.


----------



## VegasCameraGuy (Sep 21, 2020)

My 100-500 is on the UPS truck for delivery today and hope to have some results in the next few days. My only comment is that EF lenses are reaching end of life as Canon will apparently focus on the RF cameras and bodies. This means that older technology will depreciate faster as more people move to the new R style products.

If you sign up for a credit card from B&H or Adorama, you can get discounts on purchases. The $2700 100-500 saves me about $220 on sales tax from B&H or 5% off from Adorama. While spending close to $3K on a lens, saving $200 is not a big deal but $200 will buy you a 128Gb CFx card.


----------

