Z 600mm - no way to automatically correct exposure when TC engaged

[arbitrage]

Not sure, have you made your selection in CUSTOM SETTINGS B7 Keep Exp when f/ changes? Mine is selected to ISO, with that enabled your ISO levels will float, your f stop will naturally increase 1 stop with TC engaged.
Works with AUTO ISO ON or OFF. I always use AUTO ISO.

That doesn't make any sense. With Auto-ISO ON the camera will always change ISO regardless of setting B7. B7 should have no affect when in Auto-ISO but of course your ISO will still change because it is Auto-ISO and you have just lost a stop of light when engaging the TC.

As Steve mentions a few posts up, B7 only affect full manual mode.

 

[marc]

That doesn't make any sense. With Auto-ISO ON the camera will always change ISO regardless of setting B7. B7 should have no affect when in Auto-ISO but of course your ISO will still change because it is Auto-ISO and you have just lost a stop of light when engaging the TC.

As Steve mentions a few posts up, B7 only affect full manual mode.

Your absolutely correct, I should have stated that, my apologies, AUTO ISO will still do it's thing regardless of B7.

 

[O]

That doesn't make any sense. With Auto-ISO ON the camera will always change ISO regardless of setting B7. B7 should have no affect when in Auto-ISO but of course your ISO will still change because it is Auto-ISO and you have just lost a stop of light when engaging the TC.

As Steve mentions a few posts up, B7 only affect full manual mode.

100% i thought it strange but let it run just in case there was something new i had missed happening........

Only an opinion

 

[Ivan Rothman]

I started this thread. Mea Culpa
Nobody yet has a Z 600mm f4 to test, but one would think the Z 600 will work the same as the Z400 2.8 regarding whether exposure will automatically adjust in full manual mode when the TC is engaged. And reports on how the Z 400 2.8 works in this thread are confusing.
My suspicion is that correction will not occur when the TC is engaged.
I will just have to wait until I get my 600 and test it for myself. Or better yet, when Steve gets his 600 and tests it.

 

[Kuau]

I started this thread. Mea Culpa
Nobody yet has a Z 600mm f4 to test, but one would think the Z 600 will work the same as the Z400 2.8 regarding whether exposure will automatically adjust in full manual mode when the TC is engaged. And reports on how the Z 400 2.8 works in this thread are confusing.
My suspicion is that correction will not occur when the TC is engaged.
I will just have to wait until I get my 600 and test it for myself. Or better yet, when Steve gets his 600 and tests it.

Like I stated earlier I own a Z400/2.8 with built in TC and when I have B7 switched on shooting in full manual mode and engage and disengage the TC my exposure does not change at all so for me this does not work

 

[pwaring]

Like I stated earlier I own a Z400/2.8 with built in TC and when I have B7 switched on shooting in full manual mode and engage and disengage the TC my exposure does not change at all so for me this does not work

Were you testing at f2.8? If you're at f4 or above then nothing happens because engaging the TC doesn't change your aperture. This setting only comes into play when you're wider than f4.

 

[Ivan Rothman]

Were you testing at f2.8? If you're at f4 or above then nothing happens because engaging the TC doesn't change your aperture. This setting only comes into play when you're wider than f4.

Regardless of what aperture is set when you engage TC you are losing one stop of light

 

[pwaring]

Regardless of what aperture is set when you engage TC you are losing one stop of light

This just isn't true. If you have a 400mm f2.8 set to f5.6 and you engage the TC the camera will stay at 5.6. Your maximum aperture has changed from f2.8 to f4 by adding the TC but your current aperture need not change and you have not lost a stop of light. The only time you are forced to lose light is if you start wider than f4. I've been using TC lenses for years at this point since the 180-400mm TC came out and I'm very familiar with them.

You can test all this stuff on your own Z9 if you own a teleconverter. You don't need the 600mm TC to do it. Just get a lens that takes a TC and leave the camera on when adding and removing the TC and you'll be able to see it all happening for yourself.

 

[fcotterill]

This just isn't true. If you have a 400mm f2.8 set to f5.6 and you engage the TC the camera will stay at 5.6. Your maximum aperture has changed from f2.8 to f4 by adding the TC but your current aperture need not change and you have not lost a stop of light. The only time you are forced to lose light is if you start wider than f4. I've been using TC lenses for years at this point since the 180-400mm TC came out and I'm very familiar with them.

You can test all this stuff on your own Z9 if you own a teleconverter. You don't need the 600mm TC to do it. Just get a lens that takes a TC and leave the camera on when adding and removing the TC and you'll be able to see it all happening for yourself.

The 180-400 TC works like this. Engaging the TC fully wide aperture drops the fstop from f4 > f5.6.
Otherwise engaging the TC at f5.6 or slower fstop is analogous to zooming a fixed speed zoom to a longer focal length - no effect on fstop, and Auto-ISO does not change. I don't see any change with b7 ON or OFF

 

[Ivan Rothman]

This just isn't true. If you have a 400mm f2.8 set to f5.6 and you engage the TC the camera will stay at 5.6. Your maximum aperture has changed from f2.8 to f4 by adding the TC but your current aperture need not change and you have not lost a stop of light. The only time you are forced to lose light is if you start wider than f4. I've been using TC lenses for years at this point since the 180-400mm TC came out and I'm very familiar with them.

You can test all this stuff on your own Z9 if you own a teleconverter. You don't need the 600mm TC to do it. Just get a lens that takes a TC and leave the camera on when adding and removing the TC and you'll be able to see it all happening for yourself.

You are right and you have just taught me something
I just put my z 400mm F4.5 on my z9, full manual. When I am at f13 and then add 2x TC I am still at f13 and exposure unchanged
And here is what really surprised me - in full manual with auto iso turned off, if I set the maximum aperture of 4.5 and then add TC, the camera now shows aperture of 9 (as expected) but the exposure is still unchanged because even though auto ISO not on, the ISO has been automatically increased 2 stops by the camera.
so when I get my 600, I now know that even in full manual, exposure will not change when I engage TC but if I am shooting wide open my ISO will go up one stop

 

[Joel N]

This just isn't true. If you have a 400mm f2.8 set to f5.6 and you engage the TC the camera will stay at 5.6. Your maximum aperture has changed from f2.8 to f4 by adding the TC but your current aperture need not change and you have not lost a stop of light. The only time you are forced to lose light is if you start wider than f4. I've been using TC lenses for years at this point since the 180-400mm TC came out and I'm very familiar with them.

You can test all this stuff on your own Z9 if you own a teleconverter. You don't need the 600mm TC to do it. Just get a lens that takes a TC and leave the camera on when adding and removing the TC and you'll be able to see it all happening for yourself.

Actually there maybe some truth with the lost of a stop of light there. Camera usually acquire focus with the largest aperture available (lowers f stop number), it can be an instant but the aperture will open up to the widest during focusing stage to maximize light for focusing and close up to the designated aperture when taking the shot. I know it is like that on dslr but didn’t bother to really look into it on the z9. Eg. If you are shooting at 5.6 with a 2.8 lens. the focusing stage could be done at wide open to let in more light for the focusing operation. If a 1.4 tc is engaged, the max amount of light no matter what will be limited at the focusing stage, if that makes sense.

That’s also the reason why when you set your d850 or d6 to f13 it still can focus even if it is beyond f8 limit.

 

[RoyC]

Well we may be able to actually test the pros and cons of this lens next week. An individual posted over on FM that his local camera store had informed him that NPS had notified them that the lens was about to be shipped.

 

[BillW]

Actually there maybe some truth with the lost of a stop of light there. Camera usually acquire focus with the largest aperture available (lowers f stop number), it can be an instant but the aperture will open up to the widest during focusing stage to maximize light for focusing and close up to the designated aperture when taking the shot. I know it is like that on dslr but didn’t bother to really look into it on the z9. Eg. If you are shooting at 5.6 with a 2.8 lens. the focusing stage could be done at wide open to let in more light for the focusing operation. If a 1.4 tc is engaged, the max amount of light no matter what will be limited at the focusing stage, if that makes sense.

That’s also the reason why when you set your d850 or d6 to f13 it still can focus even if it is beyond f8 limit.

Unlike a DSLR, the Z9 autofocuses using the aperture you set for the lens, unless the aperture you set is smaller than f5.6, in wich case it uses f5.6 for AF and then stops down to take the photo. The Z6/Z7 versions I and II do the same.