Panasonic 7-14 F4 vs Olympus 7-14 Pro F2.8

Flare (from internal reflections of light inside the lens) is mostly caused by sunlight hitting the front element directly. When the sun is actually outside the frame you can shade the lens with your hand (making sure the hand is not visible in the picture) and eliminate the flare. CA is caused by light being bent differently for different colors. Lateral CA is so very regular and predictable that it can be easily corrected in processing because for the same setting (f-stop, focal lenght and focus distance) the same formula can be applied. Longitudinal CA is harder because it is caused by light from the out of focus background "bending around" the subject. It is therefore mostly seen when a fast (prime) lens is used wide open. It can sometimes be somewhat corrected but may require some manual action as it is not a function of where you are in the frame. Flare is totally dependent on where the sunlight comes from and hits the lens. It results in purple or other colored shapes that are hard to eliminate. The best thing is to just consider them to be artistic artifacts that contribute to the photo. Strictly speaking flare is a color aberration and can be called CA but it is typically just called flare to distinguish it from the CA that is visible as colored fringes around edges.

Andrew Ellis wrote:

I have the former lens (the Panasonic), and it's a very good performer on my 2 Olympus bodies (EM1 & EM5 II), however as has been very well documented, it does suffer from the ugly purple flare spots, when ever there's a bright light source in the image. I try to negate as much as possible by re-composing but sometimes its just unavoidable.

Reviewers say the Oly 2.8 is much less susceptible to flare. However, they also say field curvature is an issue, requiring front-focusing in order to keep both center and edges sharp.

Like a number of people, I'm therefore considering swapping for the new Olympus 7-14 F2.8 Pro version. I can part exchange the Panny (along with a couple of other bits and pieces) and get the Olympus version for just £100 ($150) trade up.

At that cost, the Oly looks like a good deal if you can live with the field curvature.

Question is to those who have had this lens, is it worth the trade up, will it be as sharp (or sharper) as my copy of the Panny 7-14, and does the Olympus resist flare much better than the Panny, and when it does occur, does it appear like normal lens flare (i.e. are the horrible purple blobs gone).

FWIW, the flare blobs are not purple and are less noticeable with this lens mounted on a Panasonic body. Some Oly shooters have resolved the purple blob issue by attaching a filter to the back of the lens. I'm not familiar with the details.

This would also complete my Olympus Trinity of 7-14 F2.8, 12-40 F2.8 & 40-150 F2.8 Pro lenses (which would be nice - but not the ultimate consideration really).

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Lets make pictures, not war........

In the image below flare is running from top right diagonally towards the center.

The Pana 7-14 is known to flare very badly on Oly cameras but not nearly as bad when a UV 2A filter (gel filter at the back) is fitted. I don't think it would flare much worse on a Pana camera than the Oly 7-14 does on an Oly camera.

I really like the Oly 7-14, but you have to learn to use it: shade a corner with you hand if needed to avoid flare and consider the curvature of the focal plane when choosing where to focus.

Paul De Bra wrote:

In the image below flare is running from top right diagonally towards the center.

The Pana 7-14 is known to flare very badly on Oly cameras but not nearly as bad when a UV 2A filter (gel filter at the back) is fitted. I don't think it would flare much worse on a Pana camera than the Oly 7-14 does on an Oly camera.

I really like the Oly 7-14, but you have to learn to use it: shade a corner with you hand if needed to avoid flare and consider the curvature of the focal plane when choosing where to focus.

Do you need to stop down to compensate for field curvature and ensure edge-to-edge sharpness? If so, this would partially erase the advantages of the lens' larger f2.8 aperture.

At 7mm you always have substantial DoF. But to maximize its use it's important to focus such that everything you want to have within acceptable focus is within that DoF. This often means focusing a bit off-center to something that is closer than what is in the center.

Below is an example of an image where the extreme wide angle at 7mm was needed (despite it distorting people near the edges). And the difficult lighting asked for f/2.8. For me the sharpness throughout the frame is acceptable. (This image was later used by a newspaper, with permission.)

7mm f/2.8

The image below was taken at f/4 and I don't see improvement in bringing more into acceptable focus. The circumstances of both the image above and below are not likely to lead to great images, but as a memory of the events they are good enough for me.

7mm f/4

Having just played with the PRO lens a bit indoors and outside. I, too, have generally found no need to stop down (and would have returned the lens if that was not the case). It stands to reason that, when there's a lot of depth to the image, getting everything in focus at f/2.8 will take a little extra work beyond point and shoot. With this lens, I've found it particularly easy to just manually tune the focus before pressing the shutter.

So far, as with the 9-18mm lens (which I love and have used a lot), I haven't found field curvature to be a concern at all. That seems to be much more of an issue in a testing lab than in real life (where one does not treat every lens identically).

Paul De Bra wrote:

At 7mm you always have substantial DoF. But to maximize its use it's important to focus such that everything you want to have within acceptable focus is within that DoF. This often means focusing a bit off-center to something that is closer than what is in the center.

What about at 14mm? No need to stop down as long as you front-focus a bit?

I rarely use the 7-14 at 14mm. On my last trip I found just one image (out of 188) that was taken with the 7-14 at 14mm (and it was at f/3.5).

I believe the field curvature is not an issue at 14mm the way it is at 7mm. However, you have to consider that DoF is smaller at 14mm than at 7mm so you are more likely to need to stop down to get enough DoF.

14mm f/3.5