Funny problem using 2X teleconverter w/D90

[DelphiNikonian]

Okay, I picked up a used AF 2X teleconverter (Quantaray 2X AF). Now when I slap a lens onto my D90, the Info display works fine. But when I slap the 2X onto the lens and then put the combination onto the D90, the Info display shows just the underline bars where one would normally see the shutter speed and aperture - or sometimes I get the underline-only for the shutter speed and a "F--" where the aperture should display. I get the same type of display if I turn on the D90 with all lenses removed. Could there be disconnected wiring/cabling in the 2X? And I don't get any response when I switch from "P" to "Auto", "M" or other modes. And the D90 won't fire at all - but as I manually focus the lens, the D90's viewfinder will signal if I'm focused.

Anyone experience this on a D90?

Derek

 

[altproto]

--
Jose

 

[westerner]

I believe that most, if not all of the "consumer" or "kit" lenses will not work with teleconverters at all. Most teleconverters advertise that they will only work with the more pro-grade lenses, like 80-200 f/2.8, 70-200 f/2.8VR, etc. Your average 18-55, 55-200, and so on, will not work, if I am not mistaken. So, that may be your problem. To repeat the previous question, which lens(es) are you trying here?
--
K.B.

 

[DelphiNikonian]

The 18-105mm VR and the 70-300mm G. But you have a point. I'll try it on my third lens and see if this makes a difference. Yep. Just tried it on my Tokina 28-80 Asph and it was a no-go. Strange that a Quantaray would only be usable on "Pro" lenses - as it makes no mention of "pro-only" on the TC. I mean, this is a cheapo 2X.

Oh well, has anyone had luck using one of those new 2x's (that you see listed on eBay for $74.95 for all the D60/70/80/90 series) with a 'kit lens'???

Derek

 

[Blufftonian]

Does the teleconverter have the electronic contacts that match those on both the Nikon body and lens? If not, then you can't expect it to meter or autofocus.

 

[altproto]

The 18-105mm VR and the 70-300mm G. But you have a point. I'll try it on my third lens and see if this makes a difference. Yep. Just tried it on my Tokina 28-80 Asph and it was a no-go.

... screw drive and in-lens motor. My line of thought was around this TC being for older AF style lenses, but you have tested 2 of them.

I think this one is fried. I know these TCs had problems when reporting correct aperture, but have never read what you describe as its behaviour. But then again, its the first case I read regarding a D90. Most were from D50s and D70s.

--
Jose

 

[Raf3]

The big problem with consumer lenses and 2X teleconverter is the effective aperture. I don't recall the specific numbers, but if you're using a Nikon 70-300mm zoom, the maximum aperture range is from 4.5-5.6. If you're trying for the longest range, you've got an max aperture of f/5.6 (you might be shooting at a smaller aperture, but the lens uses the wide open aperture to do autofocus.)

When you put a 2X telecoverter on with that lens, you reduce the aperture. The maximum aperture resulting is too small to allow the camera to perform autofocus. The problem isn't the camera, it's that the combination of a small aperture and a large teleconverter won't let the auto focus work.

-Raf

 

[DelphiNikonian]

The big problem with consumer lenses and 2X teleconverter is the effective aperture. I don't recall the specific numbers, but if you're using a Nikon 70-300mm zoom, the maximum aperture range is from 4.5-5.6. If you're trying for the longest range, you've got an max aperture of f/5.6 (you might be shooting at a smaller aperture, but the lens uses the wide open aperture to do autofocus.)

Yep, I didn't expect it to autofocus, but I DID expect the camera to function. No ability to fire at any focal length, any aperture, any ISO. Camera acts as if the lens isn't even attached.

When you put a 2X telecoverter on with that lens, you reduce the aperture. The maximum aperture resulting is too small to allow the camera to perform autofocus. The problem isn't the camera, it's that the combination of a small aperture and a large teleconverter won't let the auto focus work.

Well, DUH! Of COURSE it reduces the effective aperture! ;-) ;-) ;-)

But I don't think this is the problem. I've tried this with both an in-lens-motor lens and a from-the-body-motor lens and it just doesn't work - at any aperture, at any focal length. So I think the "electronics" on this is fried.

-Raf

 

[I Beam]

You should always mount the TC onto the lens first before mounting the combination onto the camera. I doubt that this is your problem but you might try it.

As a general rule it is not a good idea to use TCs with lenses with a focal length less than 70mm because there is a possibilty (read danger) of the rear element of the lens fouling the front element of the TC. Obviously this varies from TC to TC and lens to lens and it seems that with your TC and lenses there is not a problem.

Out of inerest I tried a x2 Kenko TC on an old Nikon 70-210 and even with the lens at full zoom with an aperture of f5.6 and an effective aperture of f11 I could get AF in very good light. However, the quality of photographs was pretty terrible.

I agree with you that there seems to be a problem with your TC.

Regards

Paul

 

[LeungPhotos]

My guess is that the Quantaray does not have the electronics built in to communicate between the lens and the body. So if you shoot in manual mode, you should be able to fire off shots. If you shoot in any other mode including P, S or A.... the body gets no readings from the lens and so it will not fire off a shot.

Switch it to manual and select your own f stop and shutter and see what happens.

The big problem with consumer lenses and 2X teleconverter is the effective aperture. I don't recall the specific numbers, but if you're using a Nikon 70-300mm zoom, the maximum aperture range is from 4.5-5.6. If you're trying for the longest range, you've got an max aperture of f/5.6 (you might be shooting at a smaller aperture, but the lens uses the wide open aperture to do autofocus.)

Yep, I didn't expect it to autofocus, but I DID expect the camera to function. No ability to fire at any focal length, any aperture, any ISO. Camera acts as if the lens isn't even attached.

When you put a 2X telecoverter on with that lens, you reduce the aperture. The maximum aperture resulting is too small to allow the camera to perform autofocus. The problem isn't the camera, it's that the combination of a small aperture and a large teleconverter won't let the auto focus work.

Well, DUH! Of COURSE it reduces the effective aperture! ;-) ;-) ;-)

But I don't think this is the problem. I've tried this with both an in-lens-motor lens and a from-the-body-motor lens and it just doesn't work - at any aperture, at any focal length. So I think the "electronics" on this is fried.

-Raf

--



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[DelphiNikonian]

I agree with you... Guess I can - now that I know it's 'broken' - take it apart and see if I can determine if it's just a shorted-out wire. If so, I can fix it. If not, I'm only out $35.

 

[DelphiNikonian]

Leung,

It's definitely got the electronics for AF - it even states it is an AF 2X teleconverter for Nikon mount. And I can see the connector points on the inside of the front opening and the connector points on the rear. As I only paid $35 for it, I don't mind cracking it open and seeing if I can fix it. And, NO, I've already TRIED AF/non-AF, "P", "M", "A", "S" and "Auto" modes. NONE of them work. Not on my 18-105mm at the 18mm end (F3.5), nor at the 105mm end, nor at any focal length on my 28-80 or 70-300mm lenses. This is probably a 'dead' unit.

Derek

My guess is that the Quantaray does not have the electronics built in to communicate between the lens and the body. So if you shoot in manual mode, you should be able to fire off shots. If you shoot in any other mode including P, S or A.... the body gets no readings from the lens and so it will not fire off a shot.

Switch it to manual and select your own f stop and shutter and see what happens.



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