C200: CN-E 18-80 and 2x or 1.4x extender compatibility

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laverdir

Well-known member
Why is listed that CN-E 70-200 supports extenders and they aren't mentioned with 18-80?

@puredrifting, you have shared your experience with extenders, did you by chance try a 18-80?

Is 1 or 2 stops light loss, with 1.4xIII and 2xIII respectively, the reason it's not listed with 18-80 when there is 70-200 available?

Or does AF system stop working in this combination?
 
Per my tech rep at Canon, "The extenders will only work with the 70-200. They will not work with the 18-80."
 
I guess that 18 is too wide and the light out of the rear element at a wide zoom would hit the extender elements at too obtuse an angle. causing vignette or more likely bottle top levels of chromatic aberration.

I also guess that an extender may work at the 50-80 zone.. which is clearly not working in the official canon zone but could work for some shots.
F8 with a dubler would doubtless confuse the AF. Of course the electronics might not work in that situation either.
There may also be clearance issues if the rear element of the lens protrudes is close to the flange. The extender protrude out from the flange.

Is there something you can stick on the front ?

Id investigate if I were going ultra ultra lite (like solo mountains) otherwise Id just get a 180 or a 70-200 (I like the non IS F4.. super cheap and light)

S
 
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Yeah,

thanks for suggestion's Sam, but need parfocal and servo "poor man's dolly".

If you look at ENG lenses, for example Canon KT17EX43BIRSE - which is 1/3 " lens with 7x crop,
extender works at 7 x 4.3 = 30.1 mm FF equivalent focal length, which isn't that far off from 1.5 x 18 = 27 mm FF equivalent.
I guess large size sensor giveth and taketh away...

Terry, would your tech rep care to elaborate why it will not work?
Is it maybe a clearance issue, as Sam suggested or the light path degrade image to unusable level?


Thanks in advance
 
laverdir said:
Yeah,

thanks for suggestion's Sam, but need parfocal and servo "poor man's dolly".

If you look at ENG lenses, for example Canon KT17EX43BIRSE - which is 1/3 " lens with 7x crop,
extender works at 7 x 4.3 = 30.1 mm FF equivalent focal length, which isn't that far off from 1.5 x 18 = 27 mm FF equivalent.
I guess large size sensor giveth and taketh away...

Terry, would your tech rep care to elaborate why it will not work?
Is it maybe a clearance issue, as Sam suggested or the light path degrade image to unusable level?


Thanks in advance
Click to expand...

Well, that lens is engineered and designed to work with the extender, which is built-in.
 
laverdir said:
Why is listed that CN-E 70-200 supports extenders and they aren't mentioned with 18-80?
Click to expand...

Seeing that the 18-80 is a pseudo ENG type hybrid lens you may consider like we used to use on 3/3" B4 ENG lenses trying out Canon's T15HD-II. This is a front mounted 1.5 x zoom through HD teleconverter. Pretty expensive new, around US$3K. They fitted onto B4 HD broadcast lenses. They could be used on 85mm up to 98mm lens barrels. Most of them had 85mm clamps as most regular 15-18 x ENG lenses had 85mm OD barrels. They have an adjustable clamp to clamp onto the outside of the lens barrel. From memory the 18-80 has a lens barrel with an OD of 84mm. I would think with a little imagination you could easily clamp one of these on an 18-80 barrel. In fact I've used an 85mm mount clamp version on a 77mm threaded lens by using a step-up ring that goes from 77mm to 82mm. Screw in the step-up ring on to the 77mm lens thread and them clamp the lens adapter onto the 82mm step-up ring. Most 82mm step rings have an OD of just on 85mm. They are not super light but as the 18-80 is pretty solidly built I think it should have no problem working with one. The BIG bonus with these is that there is NO light loss with them. So your T4.4 stays T4.4. So you could end up with a 27-120mm zoom through. You can see hem listed on this PDF:

https://www.canon-europe.com/media/kj20x82b_irsd_tcm13-971604.pdf

You might say "But hey I don't want to spend that sort of money." Fair enough I say but the reason I mention these T15HD-II adapters is quite often they sell for around US$1,000 to $1,500 used. I would suggest you try one out at a broadcast rental outfit. Somebody is sure to have one or the Fujinon equivalent you could try out. Better still if it works I can point you in the direction of one that is listed for just on US150.00. An absolute STEAL! It's not in the States but at that price if you have tested one out on the 18-80 I think any shipping and import fees on this $150.00 unit would be well worth paying. I still have my Fujinon one along with my Fujinon B4 lenses:)

BTW a bit of useless info for the day. If it's of any interest if you multiply any aperture by the adapter X factor of a rear mount adapter, let's say F5.6 x 1.4 you will end up with the effective aperture from which you can work out your light loss. i.e. 5.6 x 1.4 = 7.8, in round figures F8.0 or a one stop loss. 5.6 x 2.0 = 11.2, ergo F11.0 in round figures. That's why rear adapters originally came out at 1.4 x and 2.0 x. Before we had built in light meters in still cameras it was easy to calculate the stop increase you had to use to deliver the exposure your mighty old Weston Master, Sekonic, Minolta or whatever light meter you used back then told you to use. Very sad... I still have my 1965 Weston Master V light meter... and it still works!

Chris Young
 
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Thanks Chris, but it wouldn't make it 27-120.

Only the telephoto side of the lens can be used, the picture corners are eclipsed at wide angle.

Still good suggestion for different usage scenario, since it limits already faint zoom range.

I might grab it, it's on Summer stock clearance for 160 EUR, which is really low, but I'm afraid that this low price along with long period sitting on the shelf reflects it's condition.
 
laverdir said:
Thanks Chris, but it wouldn't make it 27-120.

Only the telephoto side of the lens can be used, the picture corners are eclipsed at wide angle.
Click to expand...

It was just a thought, exploring all angles. On the ENG lenses that the Fujinon 1.5 was designed for there were minor corner issues. On wide angle ENG lenses I grant you it is an issue because a 4.7mm HJ11 is equivalent to 15mm on S35. An HJ22x22 on S35 is just on 24mm so the vignetting issue was nowhere close to the problem on the wide. That was the case on 2/3: glass. At the full wide end I found they simply weren't as sharp as they were throughout the rest or the range. But then again we only used them if we really needed the long end without having to use the built in 2 x as that lost two stops rather than just over one. The Canon one may behave quite differently on the 18-80 hence my suggestion of trying one out. It's the old story you have to suck it and see.

Chris Young
 
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