[disconnekt]

I have a Pentax ZX-L thats been working great the time that Ive had it. The issue that I've been having now is with Macro lenses on it.

TLDR; I had gotten a Pentax DA 50mm macro last week and when on the camera every time I changed the aperture, on all other fstops it was fine until set to 2.8, on the display it showed f3.5 but when set to the "A" setting on the lens it went down to f2.8. So I figured it was an issue with the lens & sent it back.

Then I got a Sigma EX DG 50mm macro, and when I put the lens on it, with the aparture at f2.8 it shows on the display as f2.8, but when I change the aparture to f4 it shows on the display f3.5, f5.6 shows f4.5, and stopped all the way doen f32 shows f27. but when set to the "A" setting on fhe lens it goes from f2.8 to f32.

The thing is, I do have a Tamron 28-75mm f2.8 that works perfectly with it, and all the fstops show up correctly on the display.

So I'm not really sure whats going on, I dont want to keep buying & returning Macro lenses, so any help would be greatly appreciated.

[TwoUptons]

I just tried mine with a FA50 f2.8 macro, and it works fine. F2.8 is f2.8 regardless of whether I use the aperture ring or the dial and the A setting.

Same with the F50mm f1.7.

Is it possible the aperture follower (or whatever it’s called) is bent or out of alignment?

-Eric

[disconnekt]

No, everything on the Sigma lens is straight. Its pretty much in excellent condition.

---------- Post added 04-22-21 at 05:34 PM ----------

When I use the aperture in, 2.8 shows as 2.8 on the display but once I move it to a different aperture the display is off by 1/2 a stop, and only when I move the lens to the "A" setting does it show the full fstop range fine (f2.8 to f32).

But with the Tamron eveything works fine, which is weird.

[TwoUptons]

Oh, sorry. I mean the thing on the camera that follows the one on the lens.
If it’s a little out, it may cause things to read wrong on some lenses but not be enough out to be wrong on all of them...

I had a Nikon where that thing stuck sometimes, so the meter would occasionally get confused...

Just a thought...

-Eric

[disconnekt]

Theres a longish little bar on the left side of the mount, I just looked at it & it was straight. And theres a smaller bar on the right for stop-down, its straight too

---------- Post added 04-22-21 at 06:38 PM ----------

Im just going to return it for a refund :/

[stevebrot]

Im just going to return it for a refund

Let me get this straight...two different lenses don't register properly for aperture display on your camera. Regardless of how well your Tamron works with your ZX-L, the fault likely is with the body or how it is being used. Assuming this happens when attempting to use the aperture ring in other than the "A" position with those two lenses, the answer might be found in the ZX-L manual. Page 64 says that when using the aperture ring, the displayed value is an approximation and may not agree with the value set on the ring.


Steve

[disconnekt]

Let me get this straight...two different lenses don't register properly for aperture display on your camera. Regardless of how well your Tamron works with your ZX-L, the fault likely is with the body or how it is being used. Assuming this happens when attempting to use the aperture ring in other than the "A" position with those two lenses, the answer might be found in the ZX-L manual. Page 64 says that when using the aperture ring, the displayed value is an approximation and may not agree with the value set on the ring.


Steve

The settings I've set up on the ZX-L has been the same since I've got it, even when Ive used older manual lenses on it and hasnt caused my any issues until now that Ive tried those two Macro lenses on it. Like I said, the Tamron lens works perfectly with the camera.

So I shouldn't worry about the fstop on the display being a bit off from the lens fstop?

[DonV]

Correct, don't worry about it.

[TwoUptons]

Thinking about it, it would only really matter if you were logging the lens aperture somehow (and there's no EXIF to worry about).

In terms of the images, it shouldn't matter at all, unless you've noticed a slight exposure difference between the two methods...

I have to admit, when I use my ZX-L with a KA lens, I only ever use the A setting and the body control. I only use the aperture ring with older lenses...

-Eric

[stevebrot]

So I shouldn't worry about the fstop on the display being a bit off from the lens fstop?

Yes, that is correct. You might also want to consider putting the aperture ring on "A" and selecting aperture using the finger switch.


Steve