Moire at f 2!

[deltoid1]

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Had my first run in with moire today, surprised to see it at f2! That's one well corrected lens the 50 lux is.

 

Wierd thing is I saw it on a tree trunk at about 30 yards. Not used to seeing it with my 5D except on manmade items.

 

Also saw some M8 moire on a concrete wall. What to do? How are you guys ridding your images of moire?

 

Also, I do notice that that images with fine detail look almost too sharp, kind of have edge artifacts when viewed at 100%. I'm sure they would look fine printed though.

 

Do you guys sharpen your files much? Some of these files can't take any sharpening, looking almost oversharpened to start.

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[sandymc]

Carmen,

 

M8 images should be (and to my eye, are) a lot sharper in unprocessed form than those from a camera with an AA filter, e.g. your 5D. However, the downside of not having an AA filter is the moire - pretty much every M8 image that I've looked at closely has at least some. And you're absolutely right, moire (or any other aliasing type artifact) does make it a lot more difficult to sharpen an image in the post processing stage. Essentially, sharpening amplifies the areas of high spatial frequency in the image, and artifacts pretty much always have very high spatial frequency. So what you get is amplified moire! So with the M8's tendency towards moire on edges, the result can be images with edges that are quite unnatural looking.

 

Workflow-wise, best suggestion would be to de-moire first, then sharpen.

 

Sandy

[joern]

Carmen,

 

Sounds you are shooting jpg only. Try DNG and develop with C1 LE. I believe most of your concerns could be easily corrected within some RAW software. Or check and play with your in camera JPG settings.

 

But if you plan to adjust files in terms of gradation, sharpness and color there is nothing better to start with a good RAW/DNG file wich the M8 delievers.

 

I use in camera jpg only for high ISO shots and b/w.

 

Could you please post a sample image? I am interrested in what you call moire.

 

 

jørn

[deltoid1]

Carmen,

 

Sounds you are shooting jpg only. Try DNG and develop with C1 LE. I believe most of your concerns could be easily corrected within some RAW software. Or check and play with your in camera JPG settings.

 

But if you plan to adjust files in terms of gradation, sharpness and color there is nothing better to start with a good RAW/DNG file wich the M8 delievers.

 

I use in camera jpg only for high ISO shots and b/w.

 

Could you please post a sample image? I am interrested in what you call moire.

 

 

jørn

 

I am shooting raw, processing with C1. I'll post a sample in about 8 hours, (when I wake up.)

 

Basically I am seeing lots of colored artifacts on the bark of a tree, The bark has very fine detail as it is 25 yards away.

[35mmSummicron]

there are generally two types of moire patterns.

 

1) colour moire - which looks like rainbow patterns, can be corrected by software easily. there are several techniques (depending on your level of photoshop savvy) that can easily be found by doing a quick photoshop/moire removal google search. the C1 Pro installer (not sure if the same with C1 LE) has a photoshop plugin to get rid of moire, though im pretty sure it does not work in 16bit or CMYK. at any rate C1 as a raw processor does quite a good job overall of suppressing moire behind the scenes to begin with, though it would be nice to have some sort of manual control.....

 

2) pattern moire - effects the luminance of your image which cannot be easily removed. this type of moire pattern requires extensive retouching/photoshopping to get rid of seamlessly, as it will effect the texture/detail and overal tonality.

 

so depending on your shot and the extent of moire, sometimes it may just be worthwhile to leave it in......

 

hope this helps.

[deltoid1]

Here are a couple of 100% crops, ISO 160, f2. They responded very well to lab blurring of the color channels. I just tried it. I have used this technique for reducing color noise. So, looks like there is no problem. Look at the detail in these samples!

[carstenw]

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C1 has sharpening on, even when it is set to 0, IIRC. Try moving the slider all the way to the left.

[35mmSummicron]

that to me looks abit more like colour noise than moire. this looks like a common problem with sensors without AA filters--basically you get colour noise around strong specular highlights in high texture/detailed areas. the previous generation of PhaseOne backs did this alot (P25 for example - the newer line of backs seem to handle it well).

 

i swear by the "Colour Blotch Removal" photoshop action from dSLR Tools for these types of issues.

(i was recommended by the tech department for an agency i work for to use it, i have no affiliation with the developer)

 

try this out: http://actions.home.att.net/dSLR_Tools.html

 

/a

[wlaidlaw]

I wonder how much of this moire is only appearing on screens and would disappear on printing. The reason I ask is that I took a photo with the M8 for another thread of my Billingham bag. The moire looked horrendous on one of my screens, a Lacie Electron Blue 22" CRT. While I was thinking about what to do with the image, I dragged it over to park it on the other screen, a Sun Microsystems 21" CRT, and the moire almost disappeared. Drag it back and it reappears. Both screens are running in 1600 x 1200 but the Sun is running anti-moire. I printed the image and found next to no moire at all.

 

Wilson

 

PS you can pick up these wonderful huge CRT screens for next to nothing, as everyone wants flat screens. The bonus is that there is so much radiation that you also get a nice tan while working in front of them. W

[Guest guy_mancuso]

Carmen there is a plug in with c1 called Demoirze that is for Moire removal. For some strange reason I am missing mine when I switched to Mac but at least on the PC side there is one. It really works great and very simple to use. Also when viewing always look at 100 percent in PS sometimes it looks real bad at like 25 percent but when going to 100 it can disapear and is not actual there, so use 100 percent. There is also a way to avoid it while shooting if you notice it on the LCD than take the next shot and sligtly very slightly back off on the focusing. keep it to your normal stop down aperture so it is stil very sharp but sometime you have to avoid the very very critical focus if there is a issue with like clothing or soemthing but it can eaily be fixed in post also. It is the downside of no AA filter but the upside is look how sharp your images are with micro contrast and it does not happen that often. I have to do this when I shoot flat panel displays for Avionics for aircraft. If i focus on the pixels I get Moire so i back off just slightly and the images are still very sharp but i am just avoiding the moire.

[deltoid1]

C1 has sharpening on, even when it is set to 0, IIRC. Try moving the slider all the way to the left.

 

Yes, I use C1 with the 5D all the time. No sharpening applied to these.

[deltoid1]

Carmen there is a plug in with c1 called Demoirze that is for Moire removal. For some strange reason I am missing mine when I switched to Mac but at least on the PC side there is one. It really works great and very simple to use. Also when viewing always look at 100 percent in PS sometimes it looks real bad at like 25 percent but when going to 100 it can disapear and is not actual there, so use 100 percent. There is also a way to avoid it while shooting if you notice it on the LCD than take the next shot and sligtly very slightly back off on the focusing. keep it to your normal stop down aperture so it is stil very sharp but sometime you have to avoid the very very critical focus if there is a issue with like clothing or soemthing but it can eaily be fixed in post also. It is the downside of no AA filter but the upside is look how sharp your images are with micro contrast and it does not happen that often. I have to do this when I shoot flat panel displays for Avionics for aircraft. If i focus on the pixels I get Moire so i back off just slightly and the images are still very sharp but i am just avoiding the moire.

 

Thanks Guy, I'll give it a try.

[Guest guy_mancuso]

Have you found it. i use the lasso tool and make a selection around that area that has it and than do the filter , try different settings to taste . Neat plug-in