Olympus 12-100 - Need help testing

[cpt kent]

Hi,

Can I call on the assistance of someone (especially if they have a 12-100) to take a look at the attached.

I don't usually do such tests, but since this lens is intended to be my primary travel lens, and I've spend a few $ on it, I thought I'd run it over a test chart.

The photo is one of several. This one is at 35mm, ISO200, f5.6, electronic shutter, tripod, 2 second delay.

Thoughts?

 

[JOrmsby]

Corners look pretty soft to me, at least relative to the reviews I've read about this lens. Oddly though, the bottom right corner isn't as bad.

 

[Clayton1985]

IMO it's kind of hard to say with just the one image. Have you tested multiple focal lengths and do you have any other lenses that you've tested to compare with?

 

[cpt kent]

Additional images for comparison.

I've tried to do similar focal lengths, keep the aperture the same, etc.

Their may be flaws in my testing (it's just a chart stuck to the wall), but IMO the 12-100 I have should be better, especially at 5.6.

FYI, one of the things I intended to do with this lens was photograph, using high-res mode, some large graphic (ink pen) artwork that I did a long time ago, that I want to keep digitally but not physically.

I also did some with some primes, but won't use these for comparison. IMO they were all fine. The 12-100 seems to be the odd one out in any checks I've done.

 

[JaKing]

CPT, your 12-100 appears to be very slightly soft in the top LH corner. However, keep in mind that you are effectively looking at a 50 inch print at screen distances! I doubt that you would see much, if any, difference even in a 50" print ...

Otherwise, hard to see any really significant differences between the lenses. I have only examined them on my tablet so far. Maybe I will see something else when I look on my normal workstation.

[EDIT]

I have now downloaded and examined them on my w/s. Definite differences, particularly on the LH side, top and bottom. However, I reiterate what I said about looking at 100% images at 600-800 mms viewing distance.

Most of your 12-100 shots were taken at 1/8th second. This could make a very significant difference to sharpness unless your tripod is massive, and well damped.

I also have the 14-54 MkII, and it is a cracker of a lens. Better optically than any of my mFTs lenses IMHO, specially at f/5.6 ...

Improve your lighting and shoot both lenses at f/5.6 and f/8 and at least 1/100th second. You might find that the 12-100 is actually better than the 14-54 at f/8. My copy seems to be ...

[end edit]

The last test shot using the 12-100 has pretty perceptible motion blur (camera), probably due to the 1/8th second shutter speed.

From my own less stringent tests of the high res mode on my E-M1 MkII, I know that anything less than 4s shutter delay will cause blur that causes an unusable image. I was using a Manfrotto 190 series tripod with Manfrotto pan/tilt head for these shots. Even with the 4s delay, the results were slightly blurred unless I further damped the tripod by pushing down on the head mounting plate with my finger. Old astronomical telescope trick when using high magnification eyepieces.

Moral of this story is that it is all but impossible to take 'perfect' test shots unless one uses a very stable, heavy tripod, and uses multigrips to tighten all the mounting screws ...

I wouldn't worry about what you are seeing. I'll bet that you cannot see any perceptible difference in real world shots. Am I right?

--
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[cpt kent]

CPT, your 12-100 appears to be very slightly soft in the top LH corner. However, keep in mind that you are effectively looking at a 50 inch print at screen distances! I doubt that you would see much, if any, difference even in a 50" print ...

Otherwise, hard to see any really significant differences between the lenses. I have only examined them on my tablet so far. Maybe I will see something else when I look on my normal workstation.

[EDIT]

I have now downloaded and examined them on my w/s. Definite differences, particularly on the LH side, top and bottom. However, I reiterate what I said about looking at 100% images at 600-800 mms viewing distance.

Most of your 12-100 shots were taken at 1/8th second. This could make a very significant difference to sharpness unless your tripod is massive, and well damped.

I thought things were sturdy enough. Electronic shutter, two second delay, etc. Worked fine for other lenses.

I also have the 14-54 MkII, and it is a cracker of a lens. Better optically than any of my mFTs lenses IMHO, specially at f/5.6 ...

Improve your lighting and shoot both lenses at f/5.6 and f/8 and at least 1/100th second. You might find that the 12-100 is actually better than the 14-54 at f/8. My copy seems to be ...

I could. I'll try. Again, conditions were fine for the other lenses.

[end edit]

The last test shot using the 12-100 has pretty perceptible motion blur (camera), probably due to the 1/8th second shutter speed.

Wouldn't motion blur be apparent in the centre of the images? On the B&H logo?

From my own less stringent tests of the high res mode on my E-M1 MkII, I know that anything less than 4s shutter delay will cause blur that causes an unusable image. I was using a Manfrotto 190 series tripod with Manfrotto pan/tilt head for these shots. Even with the 4s delay, the results were slightly blurred unless I further damped the tripod by pushing down on the head mounting plate with my finger. Old astronomical telescope trick when using high magnification eyepieces.

Moral of this story is that it is all but impossible to take 'perfect' test shots unless one uses a very stable, heavy tripod, and uses multigrips to tighten all the mounting screws ...

I'll try it later, with better light, and a brick on top. All things that weren't required to get acceptable results with the other lenses.

I wouldn't worry about what you are seeing. I'll bet that you cannot see any perceptible difference in real world shots. Am I right?

Yes. And for general shooting it may not bother me. But for the uses I have in mind, and the amount that I paid for a 'pro' lens, I expected better.

I expect it's just my copy, but I don't know how others are seeing things.

 

[cpt kent]

My thoughts too, but I didn't add that to the OP as to not influence others...

 

[cpt kent]

Added. See below.

 

[JaKing]

Your other photos were at 1/40th (and one at 1/30 with the 12-100).

BTW, I'm not saying there isn't something wrong with your 12-100, just trying to help you get your testing methodology as right as possible so you have irrefutable evidence either way. Sh!T happens, Pro lens or not ...

Try using a finger pressing down on the tripod head mounting plate. With a shorter shutter speed, this should be OK. If you have a damping bag, use it.

Is IS on or off?

All the best with it. It's not nice to think you have shelled out all that dough and might have got a lemon!

 

[Paul De Bra]

The first image you posted had a clearly soft top left corner. The later pictures look ok to me. When I test a lens I always take a picture upside down as well (i.e. camera turned 180 degrees). After rotating back the original and upside down image should look identical.

And don't rely on a single image. From the one image posted first it looked clearly bad. The later images look fine to me. Note that if there is a slight lens element misalignment it is common for the corner opposite of the one that is a bit soft to be really sharp. In that case a tiny adjustment (spacer at the lens mount) might already alleviate the issue.

 

[MarkDavo]

[No message]

 

[cpt kent]

Thanks for your feedback.

Ill probably run some more checks soon, with an update. I need to have a think about a better (brighter) test location, for one thing.

 

[cpt kent]

E-M1 (do we need to say E-M1.1?)

Firmware 4.1 I think. Just updated it.

 

[cpt kent]

Thanks,

I took a few photos, only posted a couple.

Im aware of the upside down test trick, its probably something I'll include when I re-run the tests later. Still thinking through my re-testing setup.

 

[cpt kent]

E-M5ii this time.

Outdoors, e-shutter, 12 second delay, well stabilised tripod. Test chart fixed firmly to a well lit vertical glass door.

Same result. I haven't done the 'upside down' version yet, no time today.




12-100 at 35mm




12-100 at 70mm

 

[JaKing]

There is something odd going on here ...

The top image has sharper RHS and blurry LHS.

Bottom image has (relatively) equal softness in all corners except the bottom right, which appears reasonably sharp to me.

This appears to be an inconsistent result?? i.e. possible lens inconsistency??

 

[JOrmsby]

I agree, corners looks oddly soft. Keep in mind this is a fairly complex optical design, 17 lenses in 11 groups, so it's highly possible that some copy variation exists, and this one isn't as good as others I've seen professionally reviewed.

 

[Paul De Bra]

Top left is softest, top right and bottom left are "ok" (but not great, I don't know what to expect as I do not have this lens but I would not be thrilled as I believe the 12-40 is better). Something is not well-aligned in this lens. The top left corner in the latest images is not acceptable imho.

 

[karlreed]

Top left is softest, top right and bottom left are "ok" (but not great, I don't know what to expect as I do not have this lens but I would not be thrilled as I believe the 12-40 is better). Something is not well-aligned in this lens. The top left corner in the latest images is not acceptable imho.

 

[cpt kent]

Just an update, for anybody who is interested:

• The 'store' (I always use a store so I have someone to go back to - this is the first time I have had to), replied: "Thank you for forwarding me the example test charts. My colleague and myself have had a close look at them and believe the lens is performing to specification. With any super zoom lens softening can appear around the edges of images as you zoom in."
• Olympus service, Australia, replied: "It sounds like the element is not aligned properly, does it happen on F.4 and F.8 as well? If it does, please take it back to the store or send it to us for alignment adjustment."

So I shot the additional images requested by Olympus. The results were the same.

I've requested a replacement from the store. If they don't do this I'll have to bypass them and just send it direct to Olympus for 'repair'.