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Comment by ozzrod posted on Exposure problems with Irix 15mm lens at 03/07/2017 - 10:17
Update on my IRIx 15 Blackstone aperture mechanism/registration failure.
I emailed the distributor in Poland who were happy to restore my lens under warranty. I then discovered it would cost about AU$100 to ship it to them from Australia. Another email from me resulted in redirection to Service IRIX in Korea. They in turn emailed me a DHL account number, so the lens will be collected from my home and shipped to Korea at IRIX's cost. Should get there within a week. Pretty good service I reckon
I emailed the distributor in Poland who were happy to restore my lens under warranty. I then discovered it would cost about AU$100 to ship it to them from Australia. Another email from me resulted in redirection to Service IRIX in Korea. They in turn emailed me a DHL account number, so the lens will be collected from my home and shipped to Korea at IRIX's cost. Should get there within a week. Pretty good service I reckon
Comment by ozzrod posted on Exposure problems with Irix 15mm lens at 07/06/2017 - 08:31
phb wrote:
I would appreciate comments on the following problem encountered using an Irix blackstone 15mm f2.4.
Occasionally I get gross overexposure using this lens. I have tried it on a K1 and K3 with the same results
I have been testing it with Av and M exposure modes. - generally matrix metering. The lens is manual focus only .
When the over exposure happens , the metering values indicate a correct exposure. On most occasions, ( not sure if 100%) if I have checked the optical preview afterwards then the lens does not stop down. Operation of the preview lever has no effect for a while, then suddenly starts working.
That seems to indicate that there is an intermittent fault with the stop down mechanism. e.g if metered value is f8 @ 1/100 then shot is made at f2.4 @ 1/100.
the exif data would show f8 @1/100
I tried checking the stopdown lever in the camera lens mount but that does not operate on both cameras if there is no lens attached. - I assume that is normal .
( I remember on mechanical slr's that one could observe the lever moving by operating the stopdown lever on the body.)
I have checked the stopdown lever on the lens and that seems free and the aperture blades move very smoothly.
Has anyone experienced a similar problem?
Is my diagnosis correct or are there other things to check?
Maybe I have a faulty lens. It seems ok in all other aspects.
many thanks
Paul
I reckon it's a dud lens Paul.I would appreciate comments on the following problem encountered using an Irix blackstone 15mm f2.4.
Occasionally I get gross overexposure using this lens. I have tried it on a K1 and K3 with the same results
I have been testing it with Av and M exposure modes. - generally matrix metering. The lens is manual focus only .
When the over exposure happens , the metering values indicate a correct exposure. On most occasions, ( not sure if 100%) if I have checked the optical preview afterwards then the lens does not stop down. Operation of the preview lever has no effect for a while, then suddenly starts working.
That seems to indicate that there is an intermittent fault with the stop down mechanism. e.g if metered value is f8 @ 1/100 then shot is made at f2.4 @ 1/100.
the exif data would show f8 @1/100
I tried checking the stopdown lever in the camera lens mount but that does not operate on both cameras if there is no lens attached. - I assume that is normal .
( I remember on mechanical slr's that one could observe the lever moving by operating the stopdown lever on the body.)
I have checked the stopdown lever on the lens and that seems free and the aperture blades move very smoothly.
Has anyone experienced a similar problem?
Is my diagnosis correct or are there other things to check?
Maybe I have a faulty lens. It seems ok in all other aspects.
many thanks
Paul
I've been using my 15mm Blackstone on my K1 very happily for some months. Focuses nicely to infinity, no decentering etc - very happy. I gave it quite a bit of use over the last three days and it was fine as usual. Tonight I took it out and the camera just showed the aperture as F--. I took the lens off, cleaned the contacts, took the battery out and replaced it - no difference. I then took several pictures - according to exif all were exposed wide open at f2.4. Since getting home, I've checked the aperture lever - moves smoothly by hand and aperture changes. Tried the Irix on a K5 - exactly the same response. Tried a different lens on both the K1 and K5 and everything was as it should be. Conclusion - I've got a dud lens, with virtually identical symptoms to yours. I'll be contacting IRIX - I bought mine direct from Europe.
Rod
Comment by ozzrod posted on Exposure problems with Irix 15mm lens at 04/06/2017 - 09:29
The fault was a poor internal electrical link within the lens mount. It took only 3 weeks and two days for my lens to be picked up at my home by DHL, shipped to Korea by Air Express, assessed and repaired, and air expressed back to me in Australia, with all costs borne by IRIX Service.
And yes, my lens again works the way it used to, with in-camera adjustment of aperture and correct registration of aperture in exif.
I reckon that service is hard to beat!