Olympus 12-40mm f/2.8 Pro - Decentered?

Try f/4 instead of wide open

From https://www.opticallimits.com/m43/862_oly1240?start=1



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If you don't get older and wiser, than you just get older.

It’s much better at f/4 vs f/2.8 on my copy whereas the graphs you posted show no discernible difference between f/2.8 and f/4 at the extreme edges at 12mm. And as I said two of the corners remain sharp even at f/2.8 while the other two corners are soft which is the bigger issue. The linked images show this clearly which is what I would like opinions on.

If others have full size landscape images wide open at 12mm I’d like to hear your opinion or see your samples to compare.

I wont be shooting wide open often for landscapes obviously but it is more likely in low light and nighttime and I don’t want to settle for a subpar copy.

Different reviews will rate corner sharpness a litle different depending on the copy. Personally, i tend to shoot mine closer to f/5.6 for landscape to get the best DOF. I do notthink I ever shot a landscape at f/2.8 on this lens. Shooting wide open, shallower DOF, t wide angles often yields tricky results since often the distance of your subject in the center can be much closer to the distance of the subject at the edges.

I suggest you go out and shoot more tests but this time use a focus point closer to the corners to make sure the lens is sharp at those regions. My PL 8-18 had a reputation of soft corners wide open but in my tests, when I used focus points at the edge, not the center, my results were excellent. So again, check the sharpness in areas that you know the camera focused on, instead of an area where it was not focused on. That will be a better test of the lens. If it passes, then it is more a matter of proper focus area and DOF, not soft edges

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If you don't get older and wiser, than you just get older.

I’ve tested it that way as well. When I shoot the exact same scenes to those in the link and select the right focus point sure enough the bottom right gets sharp but then the center and left side get very very soft.

The best way to check for decentering is to take a picture and then turn the camera and reshoot the same scene.

At least in lightroom the picture will be auto oriented and viewed in the comparisson module any decentering will be easy to spot.

I’ll check that later on, thanks.

For others with this lens, do yours exhibit these soft corners at 12mm f2.8? The odd part is two opppsoing corners are soft while the other two opposing are sharp.

SFT007 said:

I’ve tested it that way as well. When I shoot the exact same scenes to those in the link and select the right focus point sure enough the bottom right gets sharp but then the center and left side get very very soft.

Click to expand...

Then you might have a problem. As mentioned in the above post, also try to shoot the same thing with the camera upside down.

If you still have an issue then try to return it. Paypal/ebay tends to favor the buyer, not the seller, unless the item was sold ‘as is’

SFT007 said:

Just picked up a used 12-40 Pro up from eBay for about $500 for an upcoming trip. Normally I use the Pana 7-14mm f/4, Oly 17mm f/1.8, Pana Leica 25mm f/1.4 and Oly 45mm f/1.8 as my go to lenses in this range but thought this 12-40 would be a good travel lens to avoid switching constantly. I've read this lens is super sharp in general so am wondering if other folks lenses also exhibit this corner softness at 12mm wide-open at f/2.8. It gets much better when I stop down from f/4 onwards. This lens specifically has soft corners in the top left and bottom right while the top right and bottom left remain sharp. I'm thinking it is decentered and/or has some weird field curvature?

Based on what I've seen my conclusion is this copy is subpar but would like others opinions since seller has no returns and I would need to argue this is defective to return it.

Link to full size samples here: https://photos.app.goo.gl/TzRUJPcfWacyRxbv7

Thanks for any feedback!

Click to expand...

It is pretty rare to hear about complaints with this lens optically but buying it on eBay it could be possible that someone was dumping a lens?

I only have a handful of F2.8 shots because the DOF is so shallow. For landscape I shoot generally between F4.5 and F7.1. But here is one F2.8 shot:


OOC LSF jpeg. The lower left is soft here, but I'd rather bet that is just a DOF issue.

SFT007 said:

Just picked up a used 12-40 Pro up from eBay for about $500 for an upcoming trip. Normally I use the Pana 7-14mm f/4, Oly 17mm f/1.8, Pana Leica 25mm f/1.4 and Oly 45mm f/1.8 as my go to lenses in this range but thought this 12-40 would be a good travel lens to avoid switching constantly. I've read this lens is super sharp in general so am wondering if other folks lenses also exhibit this corner softness at 12mm wide-open at f/2.8. It gets much better when I stop down from f/4 onwards. This lens specifically has soft corners in the top left and bottom right while the top right and bottom left remain sharp. I'm thinking it is decentered and/or has some weird field curvature?

Based on what I've seen my conclusion is this copy is subpar but would like others opinions since seller has no returns and I would need to argue this is defective to return it.

Link to full size samples here: https://photos.app.goo.gl/TzRUJPcfWacyRxbv7

Thanks for any feedback!

Click to expand...

I agree, it's badly decentered. This lens is normally really sharp, even wide open, and at 12mm you still get too much DOF to explain the soft left upper corner.

Looking at your images, the first two are great examples. You got a bad lens.

The third example is a bit hard to read, looks like you are dealing with some reflections on the left side which affect the overall contrast. Perhaps shot through a window.

Yeah I figured this was a poor copy. I don’t now if the owner is just trying to dump it or unaware but either way I’m in communication.

And yes you’re completely right the last image is from my living room window. Lazy

Not sure if the guy is trying to dump the lens. He said he's moved on to the Sony A7 and is thus selling all his MFT gear. Either way he's now acknowledged that he sees the issues with the images so we'll see how it works out.

Agree that in your image the slight softness is likely due to DOF given the short distance. That's why I was focusing on more distant objects.

It's almost certainly decentered. Mine is fine, and it is sharpest wide open, just as tested by Lenstip.

That's dreadful!

My 14-42 EZ is better than that ...

Let alone my "equivalent" lenses like the FTs 14-54 MkII and 12-100.

All the best with the seller.

My luck with this lens hasn’t been great. I’ve bought 4 copies of this lens (3 refurbished by Olympus, 1 new grey market). 2 of the refurbs were badly decentered, with the whole left or right side being soft even when stopped down. The grey market one was better, except it had a soft right bottom corner than was worse than my cheap 12-32mm lens. One refurb was optically perfect, except the manual focus clutch stopped working after several months. When Olympus fixed it under warranty it came back decentered and they couldn’t get it properly adjusted after sending it back for a second repair attempt. Ended up having to go through corporate to have the Olympus outlet store take it back for a refund.

It’s too bad as I really would like a good copy of the lens.

Yikes that’s completeley out of focus on the upper left!

Does not look good. I bought a copy of this lens as used and in like new condition. I discovered that around 25mm the upper left corner is soft at 2.8. Better and smaller area at f4 and gone by 5.6. Otherwise the lens is very good. I thought about returning it, but the price was good and unfortunately, I have evidence of decentering with many lens I have bought and many fixed lens cameras. The questions is - how bad is the issue. With my 12-40mm, I believe the issue is minor and I rarely shoot at 2.8. My new 14-150 Oly is quite good but from 70mm to 150mm the lower left extreme is a bit soft. Stopping to f8 largely fixes the problem except at 150mm where f11 is a small improvement. Disappointing but again a livable issue that will usually be fixed by stopping down and cropping. Even my 14-42ez is soft along the right side, not just corner, at 42mm. No fix by Oly service. I don't know if I just have bad luck or my experience would be more typical if people closely examined their lenses. Note, my experiences have been with Canon and recently Olympus. I have also learned that a bit of softness at 100% view may not even be noticeable in a 13 x 19 print, my largest. Of course, I wish decentering was never an issue and I didn't have to run a lens or camera through a series of tests including many FL.

Greg

Glad it worked out. Probably an honest mistake but all worked out - at least for you.

I can highly recommend the used dept of roberts camera, https://usedphotopro.com

I have purchased five lenses from them in the past two years, four of them Used. All included excellent ratings, pictures of the product, return period, free shipping, and a 180 or 1 year Mack warranty are included. I just picked up a “Mint-“ condition Oly 12-100 from them with a six month warranty. Last summer I got the Oly 40-150 Pro with a year warranty in “Excellent” condition.

At the moment they do not have any 12-40 Pro lenses but that can change fast.

Tip: If you buy used from them use offcer code Newbie, or Take5 as this will get you 5% off the price - which is one of the reasons I bought four Used lenses from them, the others being the Oly 60mm macro and 9-18 lens (both included one year Mack warranty).

The third shot at the bottom left seems to show an effect that I see as a hint that maybe you shot through a (closed) window. That will certainly cause softness depending on the angle the light comes from.

Best is to shoot a fairly flat scene, certainly not through a window (not even an open one), and also not with long distances (to avoid air turbulence from having effect).

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Getting to know the Olympus OM-D E-M5 II.
Public pictures at http://debra.zenfolio.com/.