Report: New Canon Super Telephoto Lenses Coming in May

[mimbu]

The discussion was about a switchable separate 1x-1.4x TC (echoing previous discussions about a switchable 1x-1.4x-2x TC that resulted from online misinterpretation of a Canon patent). The desire is for a standalone optic that is added to and mounts behind the lens like the current 1.4x and 2x TCs. The explanation was about why that is not technically feasible without additional optics for use at '1x'.

Then we are talking about completely separate things. At least you're not QUITE as big a moron as I thought you were, you just can't write well.

 

[neuroanatomist]

Then we are talking about completely separate things. At least you're not QUITE as big a moron as I thought you were, you just can't write well.

A 1x-1.4x switchable TC is NOT just a matter of 'adapting it into a separate teleconverter'.

A 1.4x TC built into a lens does not have to be any different to a separate 1.4x TC added to a lens.

No, we were talking about the same thing. You quoted my reply about a 1-1.4x switchable TC and stated, "... separate TC added to a lens". Your words. You were just confused, and are now trying to move the goalposts after being called out on your idiocy. Yet another fail. You should quit while you're behind, but you're probably too immature and weak to do so, therefore on this issue I won't bother replying to more of your asinine drivel.

 

[Darrell C]

I just want a RF 28 F1.4 L VCM....

 

[neuroanatomist]

I just want a RF 28 F1.4 L VCM....

You and someone else I know... 14-20-24-35-50-85, pretty crowded space already, but hope springs eternal!

 

[AlanF]

You and someone else I know... 14-20-24-35-50-85, pretty crowded space already, but hope springs eternal!

14+20+24+35+50+ 85 = 228. Double that and I'll start getting interested.

 

[neuroanatomist]

14+20+24+35+50+ 85 = 228. Double that and I'll start getting interested.

You would be interested in an RF 456mm f/1.4L VCM? I’d think that the 325mm diameter front element would make it a wee bit heavy.

 

[P-visie]

You would be interested in an RF 456mm f/1.4L VCM? I’d think that the 325mm diameter front element would make it a wee bit heavy.

Yes but @AlanF’s wallet will be so much lighter that carrying this behemoth lens into battle will not be a problem.

 

[AlanF]

You would be interested in an RF 456mm f/1.4L VCM? I’d think that the 325mm diameter front element would make it a wee bit heavy.

Dear me, you are out by a factor of 2. Add them up, then doubling the focal length means using Canon's method of welding on a 2x TC. So it's only 163mm, = a 456mm f/2.8, which is hardly more than a 400mm f/2.8.

 

[justaCanonuser]

For those interested in my reports about our Nikon Z8 & Z600mm f/6.3 PF AF issues, with and w/o Nikon's native 1.4x Z TC, a brief update. We AFMAd both combos with my old Spyder Lenscal, distance 10 m (typical setting for shooting smaller birds). Without TC it showed a massive backfocus, with TC on it was even worse. The Z8 allows to save different AF microadjustment settings for the combo with and w/o TC, fortunately. Our first days out for birding after that procedure showed a substantial improvement in AF performance for both combos, in fact the combo with TC was the first time really useable without residing to manual focusing. Only real action with birds in flight is not yet tested due to the lack of occasions.

So it really makes sense that Nikon still offers the option in their Z camera menus to AFMA lenses (at least in their pro/prosumer cameras). Canon, by contrast, obviously relies much more on auto correction algorithms "under the hood" with the RF system. So far, I have no complaints, as a Canon user I am happy that I don't have to bother anymore with AMFAing all my "AF critical" lenses, what always required quite a bit of work.

 

[justaCanonuser]

It seems to me that with MILCs the issue is usually how accurately the lens can move compared to how much the camera told the lens to move, and how well the camera can know how much the lens actually moved without continuing to focus during the movement when processing cycles might be better spent for predictive analysis of where the target will be when the shutter (mechanical or electronic) is actuated. Move and refocus is much slower than measure focus, tell the lens which way to move and how far, then confirm the lens has moved that far without measuring focus again, and take the picture.

In fact, with DSLRs it was basically the same procedure, despite they had a separate AF sensor (for shooting with OVF). The camera needs a reliable info about the AF drive's exact position to able to focus fast and accurate. The difference is that ML cameras, using their image sensor, can reside to simple contrast AF if other information is lacking, but that requires AF pumping and slows down the whole focusing process so much that you can forget about shooting action.

With our Nikon Z system it turned out that the camera received a wrong information about the real AF drive position, so the lens was mechanically not adjusted to the camera. I don't know how Canon's AF system works exactly (surely details are protected), but seemingly it delivers more information about the AF drive's exact position so the camera can adjust its AF system to a particular lens. This explains also why some older EF lenses don't work very well with the new R cameras. I recently sold my old EF 300mm f/4.0 L IS USM, which still was in good condition, because it pumped too much on my R7 and R52, it wasn't really useable anymore with AF switched on. So, this old lens is obviously not able to send enough data to the camera for any AF adjustments.

 

[justaCanonuser]

That sounds like the original 7D in AI Servo mode.

The 7D I and II needed a lot of light, then their AF perfomances improved, in particular the Mk II started to perform substantially more accurately. So their AF sensors were quite noisy.

 

[Michael Clark]

In fact, with DSLRs it was basically the same procedure, despite they had a separate AF sensor (for shooting with OVF). The camera needs a reliable info about the AF drive's exact position to able to focus fast and accurate. The difference is that ML cameras, using their image sensor, can reside to simple contrast AF if other information is lacking, but that requires AF pumping and slows down the whole focusing process so much that you can forget about shooting action.

With our Nikon Z system it turned out that the camera received a wrong information about the real AF drive position, so the lens was mechanically not adjusted to the camera. I don't know how Canon's AF system works exactly (surely details are protected), but seemingly it delivers more information about the AF drive's exact position so the camera can adjust its AF system to a particular lens. This explains also why some older EF lenses don't work very well with the new R cameras. I recently sold my old EF 300mm f/4.0 L IS USM, which still was in good condition, because it pumped too much on my R7 and R52, it wasn't really useable anymore with AF switched on. So, this old lens is obviously not able to send enough data to the camera for any AF adjustments.

Yes, DSLRs did this by necessity so that the mirror could begin swinging up while the lens was still moving and reporting its position to the camera. But some folks seem to think that with MILCs they constantly refocus until the shutter is activated (either mechanically or electronically).

As for why your EF 300mm f/4 L IS with a 1991 design isn't as good with newer MILCs, please see Roger Cicala's old blog entry Autofocus Reality: Part 3B from back in 2012. He explains that Canon upped the game around 2010 as to how accurately the lens reports the focus position to the camera.

 

[Michael Clark]

The 7D I and II needed a lot of light, then their AF perfomances improved, in particular the Mk II started to perform substantially more accurately. So their AF sensors were quite noisy.

Even in dimmer light (night/indoor sports) I found the 7D Mark II was much more consistent from shot to shot than the 7D. A 10 shot AI Servo burst with the 7D Mark II would be dead on for around 8-9 of them and just a tad off for 1-2 frames, usually when an athlete changed direction. The 7D would be on for 2-3 frames (in any random positions within the 10 shot burst), slightly off for 2-3 frames, more than slightly off for 3-4 frames, and the rest would be really out of focus flyers.

 

[Michael Clark]

The 7D I and II needed a lot of light, then their AF perfomances improved, in particular the Mk II started to perform substantially more accurately. So their AF sensors were quite noisy.

The baseline for an APS-C DSLR camera is narrower due to the narrower semi-silvered portion of the narrower reflex mirror.

 

[justaCanonuser]

The baseline for an APS-C DSLR camera is narrower due to the narrower semi-silvered portion of the narrower reflex mirror.

Yes but this doesn't explain the light dependent behavior, noise (and contrast on the AF sensor) does.

 

[justaCanonuser]

As for why your EF 300mm f/4 L IS with a 1991 design isn't as good with newer MILCs, please see Roger Cicala's old blog entry Autofocus Reality: Part 3B from back in 2012. He explains that Canon upped the game around 2010 as to how accurately the lens reports the focus position to the camera.

I know, I loved to follow his blog for many years. But in real life, the old EF 300mm f/4.0 L IS USM worked quite well even with my 5D4. Interestingly, my old EF 500mm f/4.5 L USM from 1995 worked still surprisingly well with my R7, in contrast to my 300mm, a lens that was introduced in 1997.