I removed the AA filter from my 5D MkII

[+evenstar]

actually from a computer screen, picture shot without AA filters might look bad in some cases, but if printed out, those without AA filters can bring out much more details, probably due to higher dpi.

taking out the AA filter increases DPI?? :dunno:

 

[mattlock]

i see,

you don't get any funny things? because sometimes people do it for IR photography, i.e. they put an ir filter over lens and can shoot with handheld speeds..

and apparently, for those they get some form of funny results sometimes

so far so good.took a shot of my friend's pantry at f/1.4 and the wording on the labels look well defined to me. (focus is on the left middle part of the picture) I wouldn't call this a definitive shot but just posting it up for you to take a look first
http://superhyperreal.com/test1.jpg
this one's iso 200 f/1.4 1/90th I think?
sharpening is 25 and colour reduction is 7 on ACR.

purple fringing is quite obvious and there is some CA on the very thin lines on the nutella bottle cap
it's starting to look more like how my medium format back actually reacts...
I did a few test shots at a smaller aperture and there are less CA problems

 

[mattlock]

i see,

you don't get any funny things? because sometimes people do it for IR photography, i.e. they put an ir filter over lens and can shoot with handheld speeds..

and apparently, for those they get some form of funny results sometimes

no comedians or dead people in my photos yet.
but seriously...I've seen some modified cameras for IR they're quite interesting. there are also special backs modified for black and white only
those are expensive...
but I wouldn't know about IR.

 

[night86mare]

that's interesting, maybe i got it wrong when reading about the fujifilm is-1 a while back:

here

not the exact site, i am still searching for it, but without the hot pass filter you can see the unfiltered images have a very interesting color cast.

 

[chopper]

I hate purple fringing... and definitely don't like the Moire pattern either, so looks like my 5D will be spared of any transformation.

 

[rendition]

I don't see how this can be a benefit... images coming out from 5DMII not sharp enough meh LOL and yes like what others mention, I'd definitely not want to trade it with CA and Moire...

 

[CYRN]

that's interesting, maybe i got it wrong when reading about the fujifilm is-1 a while back:

here

not the exact site, i am still searching for it, but without the hot pass filter you can see the unfiltered images have a very interesting color cast.

mabbe you should be looking at the Leica example when the hot-filter is not enough, you'd get purple cast on blacks.

But I tot that is not the same as AA filter.

 

[night86mare]

mabbe you should be looking at the Leica example when the hot-filter is not enough, you'd get purple cast on blacks.

But I tot that is not the same as AA filter.

hrm, i am reading about aa filter,

i found something on FM here

it should be the same thing

 

[mattlock]

I don't see how this can be a benefit... images coming out from 5DMII not sharp enough meh LOL and yes like what others mention, I'd definitely not want to trade it with CA and Moire...

that's fine. any lens wide open is going to have some CA, I guess the AA filter helps to mask that up.
but my retoucher can remove CA easily, he can't bring back definition in the picture.
I'll post some smaller aperture shots that will deal with the CA.

 

[nightpiper]

Think this is a better link for this AA mod explanation.
http://www.maxmax.com/hot_rod_visible.htm

Such mod is not new but i'm not sure if the trade off & price for modding are worthwhile.

What i found was, if i shoot RAW in my 40D & use DPP to process with sharpness set at +5, the results looks similar (may not be exactly the same) to this removal of AA filter.

I also feel that slanted straight lines tend to look more "steppy", if there's such a word coined. :bsmilie:

 

[CYRN]

hrm, i am reading about aa filter,

i found something on FM here

it should be the same thing

I follow through to this link... not sure if that is what being modified on mattlock's cam tho...

http://forums.dpreview.com/forums/read.asp?forum=1032&message=26236283

 

[mattlock]

I finally had the chance to do abit of testing with a friend's 5D.
First thing's first:
it's near impossible to get everything aligned.
Slight variance in positioning due to things like the release plate not being exactly at the same spot...The two files are cropped down abit to match up in terms of positioning.

Next is colour temperature variance...not sure if the colours between different units of 5D mkII cameras are different but one camera was definitely more magenta, one was more on the green side. The modification of the glass definitely plays a role here. The difference in colour cast probably has an effect in the contrast of the image.

focusing variance was also an issue. out of the 10 different series of shots we did this was the most close series of pictures we had in terms of focus from two different cameras using the same lens
85mm f1.8 wide open

focus is supposed to be right smack in the centre of the picture, on the right edge of the grey speckled pillar.
To compensate for focus error I guess you'll have to compare detail of the closest object to the furthest object.

Nonetheless, certain interesting details can be observed when zoomed in to 400%, visible at 200% too.

Would love to do a stricter test to see the effect of this modification, when I have the time

full size (slightly cropped) jpegs here
Processed in ACR, with sharpness set at 10 radius 1.0, noise reduction at 2

http://superhyperreal.com/compare1.jpg
http://superhyperreal.com/compare2.jpg

 

[alexj]

Might see more difference in Lab test shots.

In your 'real world' photo comparison, it's hard to tell what attributes to the modification and not due to other variables like focus, back-focus alignment, quality difference of the AA filter vs the replacement glass, etc.

As for white balance it could be due to the quality difference in the filter and the replacement glass. Another reason too is since no *two same model cameras are actually 100% the same; the differences in electronics/optical materials in the camera vary, especially when comparing different batches.

On the plus side, if it works better for your style, then its worth the money spent.

 

[mattlock]

yup there are too many variables. I have to say that focusing very exactly is very very tough.

between different units like you said there are variations too..

so far there seems to be less of a smearing effect and abit more microcontrast without the AA filter.
but I'll see the actual effect of my modification on the next job I use the camera on. Those things (esp pixel smearing) become very apparent when we start upsizing.

Might see more difference in Lab test shots.

In your 'real world' photo comparison, it's hard to tell what attributes to the modification and not due to other variables like focus, back-focus alignment, quality difference of the AA filter vs the replacement glass, etc.

As for white balance it could be due to the quality difference in the filter and the replacement glass. Another reason too is since no *two same model cameras are actually 100% the same; the differences in electronics/optical materials in the camera vary, especially when comparing different batches.

On the plus side, if it works better for your style, then its worth the money spent.