p.1 #1 · M.Zuiko Digital ED 50-200mm f/2.8 IS PRO Defective and a Caution
Got back from a trip and had two new M.Zuiko Digital ED 50-200mm f/2.8 IS PRO lenses waiting for us. Today I had a chance to play with them in the house.
One lens appears to function properly. The other is defective, bummer.
It has an issue of being soft at the 50mm range, BUT, the main defectiveness is holding the focal plane from 50mm to 200mm.
At 25 feet distance to target, focusing at target using 50mm setting, then zooming to 200mm, the focus is now moved forward 8 feet. That distance shrinks when you get closer and grows when you are further from target. Tried it on three different OM-1 mkii bodies, same results.
Not sure if there are any replacement available at the moment, will find out tomorrow.
Interesting that the two lenses are 1 number different in the serial number.
* The Caution is using CA-F +MF. The zoom ring is very close to the focus ring. Holding the lens my fingers naturally touch the focus ring. And just by touching you activate the manual focus and can very easily change the focus plane. Not what you want to do and not know it. Using this lens we will prevent blurry images by turning off the manual focus feature with CA-F.
If you try to zoom fast while shooting... auto focus will drop out while zooming and shooting at the same time. You are not going to know which images are missed focus until you review. The 150-400 also does it but this lens seems to be worse. So watch the focus while zooming while pushing down the shutter button.
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Cheers, Patrick.
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p.1 #2 · M.Zuiko Digital ED 50-200mm f/2.8 IS PRO Defective and a Caution
Follow up,
A UPS label is generated for an exchange. Yea!
The lens is not a parfocal lens, meaning when the lens zoom is adjusted the focus is not changed. It is more the standard varifocal lens found most common. I guess some people use the term "breathing".
Our second lens has a slight focus shift to the back around an inch or so at 25 feet. Having the defective lens having that much of a focus shift makes the autofocus work extremely hard to catch up after zooming.
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p.1 #4 · M.Zuiko Digital ED 50-200mm f/2.8 IS PRO Defective and a Caution
This is the second report of faulty 50-200mm that I've seen. I find this a bit concerning in a premium product.
Even your second lens having a 1 inch focus shift doesn't really seem to be acceptable!
p.1 #6 · M.Zuiko Digital ED 50-200mm f/2.8 IS PRO Defective and a Caution
Tom Reynolds wrote:
OK is the correct test to AF at 50mm, then zoom to 200mm and see if it retains focus. I will test my second lens.
Tom what I did, and found it easier to go from 50 to 200mm.
This by far not a scientific testing procedure, just a quick way to see what is going on.
Used CA-F + MF
Peaking when manual focusing and the color of your choice.
AF tab #7, "MF Assist" "Peaking On"
AF tab #7, "Peaking Settings", "Peaking Color" (I use Yellow), and "Highlight Intensity" ( I use HIGH)
Find a flat wall with a picture. You can use anything that the autofocus will lock onto.
Used a tape measure and I measured out 25 feet. marked spot. You can use any distance.
Put tape measure on ground and feed out 10 feet from the wall so I can see it from 25 feet away.
Set zoom at 50mm and auto focus at target from the 25 feet mark using proper exposure and at f/2.8 aperture.
Do not touch the manual focus ring or the shutter button.
Zoom ring to 200mm.
Look at target and see if it is pretty close to focus. Not being a parfocal lens it will be off some but not 8 feet like mine.
At this point you are now using the manual focus ring with peaking.
Slightly move the manual focus ring and you will see a thin line of color of what was focused at 50mm.
With mine it was a matter of looking down at the tape measure and seeing where the line was intersecting the tape measure.
Do it several times to get the hang of it and to compare results.
First lens at 200mm I needed to move the focus ring about 40 degrees to get the target to light up using the manual focus ring with peaking. That is how much movement needed to get focus on target from the 50mm start.
My second lens I had just a slight movement and the target light up more as I slightly moved the focus forward. I estimated about a inch and I'm happy with that.
