Link - Collection for CornerFix Profiles

[sandymc]

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Sandy,

 

Above, thanks for the suggestion of creating the profile at f8- this should work fine. I think I had been developing my base shots fully open. Also, as a suggestion for lighting, outside with a white board has provided wonderfully even lighting.

 

Since the latest firmware, it appears that the corrections vary for each ISO level. From Leica's literature:

 

• New ISO setting-related vignetting correction: strong correction at ISO 160, lowest ISO

correction at 2500, interpolated for intermediate ISO steps.

 

Does this now mean we need to make profiles for each ISO setting, and if so, how fine: 200, 400, 800, 160, or every half stop, etc.?

 

Thanks, Sandy.

 

If you want to correct images taken with coded lenses (either physically or via the M9 menu), then yes, you need a profile for every ISO setting. If you leave the lens uncoded, which I recommend, then a single profile is fine.

 

Sandy

[Doc_P]

Here are my ZM 18mm profiles.

 

You don't have to worry about dust bunnies at all, the vignetting gradients are vector calculations to my knowledge. The dust bunnies remain on corrected shots even if they are in the calibration target.

Daniel,

Merci vilmols, Vielen Dank, Thanks a lot for your ZM 4/18 Profiles. I could use them as is-no probs. They really helped to rescue some of my favoritye winter/snow-landscapes.

 

&a compliment for your remarkable protfolio---really worth a visit...

 

 

Axel

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[250swb]

Sandy, you are very clever!

 

I got Cornerfix working and the essentials are far easier than the things I was reading/imagining in the instructions. I've got a pretty accurate profile for my 21mm CV that seems to work over a number of different images and situations so thats good. I'm finding the lens is a bit 'wild' with the camera coding turned off though, and my 'Off' profile doesn't work as well as the coding 'On' profile using two white card images shot at the same time for creating the separate profiles. I'll keep experimenting when I have time. But thanks for now.

 

Steve

[ghealey]

Guys - my first post so please excuse me if i am breaking any protocols or asking questions that have already been answered - i am just looking for help.

 

I just got my M9 this week and i picked up a CV 15mm as i wanted something wide - the lens exhibits all the classic vignetting and red edge characteristics everyone is seeing but is otherwise excellent.

 

I am trying to use CornerFix to correct the images but am suffering with creating a good profile. The process for creating the profile is easy enough - the execution is challenging. I use a gray card and shoot from extremely close up to get the card to fill the frame (a couple of inches) as the lens is so wide. This close up makes it difficult to light evenly as either the camera or my head blocks the light. The resulting profile(s) do not work well.

Today i set up in a studio with an evenly lit mid-grey backdrop and created 6-7 new profiles with various lighting setups. Strangely, they all work about the same and are an improvement on my earlier efforts, but are not great. The red edge has been fixed, but any highlights in the photo are badly blown out.

 

I know a lot of you are seeing excellent results from CornerFix and would appreciate you sharing how it was achieved.

 

What would be useful is if you could mail me your profiles to see if they work better than what i have created - i know there is pushback on this due to camera/lens variations but surely this is relatively small compared to all the other variations i am introducing by shooting a gray card - profiles can be sent to ghealey@pacific.net.sg

I very much appreciate your support

Geoff

[ghealey]

Guys - my first post so please excuse me if i am breaking any protocols or asking questions that have already been answered - i am just looking for help.

 

I just got my M9 this week and i picked up a CV 15mm as i wanted something wide - the lens exhibits all the classic vignetting and red edge characteristics everyone is seeing but is otherwise excellent.

 

I am trying to use CornerFix to correct the images but am suffering with creating a good profile. The process for creating the profile is easy enough - the execution is challenging. I use a gray card and shoot from extremely close up to get the card to fill the frame (a couple of inches) as the lens is so wide. This close up makes it difficult to light evenly as either the camera or my head blocks the light. The resulting profile(s) do not work well.

Today i set up in a studio with an evenly lit mid-grey backdrop and created 6-7 new profiles with various lighting setups. Strangely, they all work about the same and are an improvement on my earlier efforts, but are not great. The red edge has been fixed, but any highlights in the photo are badly blown out.

 

I know a lot of you are seeing excellent results from CornerFix and would appreciate you sharing how it was achieved.

 

What would be useful is if you could mail me your profiles to see if they work better than what i have created - i know there is pushback on this due to camera/lens variations but surely this is relatively small compared to all the other variations i am introducing by shooting a gray card - profiles can be sent to ghealey@pacific.net.sg

I very much appreciate your support

Geoff

 

Anyone able to help? This is driving me crazy

Geoff

[jaapv]

Blown out highlights are not fixed by Cornerfix - Blown-out highlights are fixed by proper exposure. Wideangles ae a bit difficult in that respect, as the lens will often take in a wide dynamic range. You should expose like you did slide film - expose for the highlights in contrasty situations, and only blow out specular highlights.

[sandymc]

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Anyone able to help? This is driving me crazy

Geoff

 

Geoff,

 

My suggestion would be to use an evenly lit wall rather than a grey card; CornerFix is relatively tolerant of imperfections that are small relative to the frame size (so e.g., it can be a brick wall), but can't easily tell the difference between vignetting and uneven lighting.

 

Some people have also had success by just putting a piece of paper over the lens as a diffuser, but as a technique you're very dependent on the uniformity of the paper, and even then you have to point the camera at something relatively evenly lit.

 

Sandy

[jdavidr]

Geoff,

My suggestion would be to use an evenly lit wall rather than a grey card;...you have to point the camera at something relatively evenly lit.

Sandy

 

Sandy, a quick question that may have been answered before -- Does the white balance setting matter when creating the profile? I created my CV15 profile using an evenly-lit light table while moving the camera so it's pretty even. Before snapping the profile shot, I manually white balanced the camera using the same technique. I've noticed when I use that profile in daylight, that I'm still getting some red edge. Should I re-do the profile in daylight?

 

thanks,

david

[sandymc]

Sandy, a quick question that may have been answered before -- Does the white balance setting matter when creating the profile? I created my CV15 profile using an evenly-lit light table while moving the camera so it's pretty even. Before snapping the profile shot, I manually white balanced the camera using the same technique. I've noticed when I use that profile in daylight, that I'm still getting some red edge. Should I re-do the profile in daylight?

 

thanks,

david

 

David,

 

Slightly complicated answer to that one: white balance as set on the camera doesn't matter - CornerFix ignores that. The actual light source however can matter. Specifically, if you have a light source that has a somewhat uneven spectrum, then the actual vignetting characteristics of the lens/camera combination can be different to that under daylight. E.g., if you happen to shoot sports scenes under artificial light, you will find that some high intensity lights used in such situations have odd characteristics. Likewise, some fluorescent lights will give green edges if you use a daylight profile. So, I'd guess that your light table has a spectrum that is different enough to daylight to give a slight red edge.

 

Sandy

[jdavidr]

Thanks for the reply. I think I'll just make another profile using straight daylight and see if that doesn't clean things up. It's odd, since it doesn't happen all the time, only with certain light -- low angles, overcast. Maybe those photos have more UV/IR wavelengths?

 

Post-CF examples with the red fringe (on the left):

2010-05 Mobius 5 - 10012's Photos

2010-05 Mobius 5 - 10012's Photos

2010-05 Mobius 5 - 10012's Photos

 

Post-CF (same profile) example without:

2010-05 Mobius 5 - 10012's Photos

[paolocava]

Anyone able to help? This is driving me crazy

Geoff

 

Ciao,

I have used a white piece of plastic (from a plastic dish) which I cut to a size in order to fit perfectly on the front filter of my lens, in this way there is non need to take a picture of a wall or a grey card and the white will fill the picture.

Then I set the white balance of my M9 on manual and take the first shot.

The following shots are with different exposures up to + 3.

Cornerfix is fixing both vignetting and red/cyan edges and I use the picture to create the lens profile.

 

It works perfectly.

[ghealey]

Thanks guys for the suggestions - I will give them a try - especially the white plastic disc

Geoff

[Manolo Laguillo]

Here are my ZM 18mm profiles.

 

Thank you very much for your profiles, thrice!

 

They do the work perfectly!

 

Nice day,

 

Manolo