• Please use real names.

    Greetings to all who have registered to OPF and those guests taking a look around. Please use real names. Registrations with fictitious names will not be processed. REAL NAMES ONLY will be processed

    Firstname Lastname

    Register

    We are a courteous and supportive community. No need to hide behind an alia. If you have a genuine need for privacy/secrecy then let me know!
  • Welcome to the new site. Here's a thread about the update where you can post your feedback, ask questions or spot those nasty bugs!

Back and Forth (Focus issue)

Ralph Honsbeek

New member
Camera: Canon 1D Mark 3
Lens: Canon EF 24-70mm F2.8L USM

Back to Front , I am lost yet again ...

Hi there , Just picked up a sparkling new 24-70 F2.8 L USM !!!
yes yes I know, very heavy indeed , need to get use to this baby ...
Love it so far , Love that it has CA (Circular Aperture) ^^

OK now here comes the thing, tested the lens (second hand by the way UW serial)
and in first glance the focus seemed pretty close to dead sharp) Now I am seeing some
slight softness in the focus. Held the camera very tight like I always do and sufficiant
sutter speed , however , I took some head shots , aimed on the eye but mouth and lips got
in the sharpness I was looking for. So correct me if I am wrong the lens is "back fosusing" ?

So I went in to my 1D Mark 3 Micro Adjustments settings , and tried it out a bit , I have left it for now on +3 (Plus 3) dialed it to the right so to speak.

I am always confused on which was to correct for the micro adjustments. If it is on +3 and the lens seems to be back fosusing , my question ultimately is , in which direction should I try and correct ?

I have calibrated and tried to use the micrso adjustment guide on this forum and I came out at +3 to be in focus. However I am confused a bit ,

Thanks to anyone with the patience to indulge ,

Kind Regards

Ralph
 

Cem_Usakligil

Well-known member
....I took some head shots , aimed on the eye but mouth and lips got in the sharpness I was looking for. So correct me if I am wrong the lens is "back fosusing" ?

So I went in to my 1D Mark 3 Micro Adjustments settings , and tried it out a bit , I have left it for now on +3 (Plus 3) dialed it to the right so to speak.

I am always confused on which was to correct for the micro adjustments. If it is on +3 and the lens seems to be back fosusing , my question ultimately is , in which direction should I try and correct ?

I have calibrated and tried to use the micrso adjustment guide on this forum and I came out at +3 to be in focus. However I am confused a bit ,
Hi Ralph,

Are the lips and mouth closer to the lens than the eye? If so, it is front focusing. If they are further away than the eye, it is back focusing. Front focusing is to be corrected by dialing a +, back focusing by a -. If it is on +3 and the lens is back focusing, then you have to dial in +2 or less. HTH...

Cheers,

Edit: changed + and - signs
 
Last edited:

Ralph Honsbeek

New member
Hi Ralph,

Are the lips and mouth closer to the lens than the eye? If so, it is front focusing. If they are further away than the eye, it is back focusing. Front focusing is to be corrected by dialing a +, back focusing by a -. If it is on +3 and the lens is back focusing, then you have to dial in +2 or less. HTH...

Cheers,

Hi Cem ,

Well have a look at any face , I am in the opinion that the mouth and lips come before the eyes do,

http://www.flickr.com/photos/tvphoto/352906361/sizes/o/

^^ So I guess the eyes are father away and the mouth is closer.
When I still focus on the eyes at +3 the eyes are still a very small amount soft, and the
lips are nicely in focus, So I guess adding the Plus value a little more , like you said.

I must tell you that I am obsessively strict when it comes to my sharpness.
I once had to bring back my 200MM F2.8 back to the service center just to get that dead sharpness , which the 24-70 is known for ...

I'll give it another try and get back to you if needed ...

Bedankt voor je hulp !!! ^^

Ralph

Edit by Cem: changed + and - signs
 
Last edited by a moderator:

Cem_Usakligil

Well-known member
...Well have a look at any face , I am in the opinion that the mouth and lips come before the eyes do,

http://www.flickr.com/photos/tvphoto/352906361/sizes/o/

^^ So I guess the eyes are father away and the mouth is closer.
Well I had a smile on my lips when reading your reaction as I have expected it. The reason why I made this explicit is that if the photo is taken from high above the person (and/or to the side of the face), the nose and the lips will be further away than the eyes ;-).

...When I still focus on the eyes at +3 the eyes are still a very small amount soft, and the lips are nicely in focus, So I guess adding the Plus value a little more , like you said.
Yes indeed.

In short, if FF: go to plus correction (add), if BF: go to negative correction (subtract).

Graag gedaan :)

Groetjes,


Edit by Cem: changed + and - signs
 
Last edited:

Ralph Honsbeek

New member
Well I had a smile on my lips when reading your reaction as I have expected it. The reason why I made this explicit is that if the photo is taken from high above the person (and/or to the side of the face), the nose and the lips will be further away than the eyes ;-).

In short, if FF: go to plus correction (add), if BF: go to negative correction (subtract).

Graag gedaan :)

Groetjes,

Cem , So I am actually still trying to determine if the lens is actually FF-ing or BF-ing.
So to get back to the face , and not any crazy angle just a straight up angle , then when
having the micro adjustment at 3+ and aiming the eye , the lips come in focus , so
the lens is BF , correct or not ? ^^

Add + value to correct ?

I'll keep my final question to be this then ...

Cheers .

Ralph (Seoul Zuid Korea)

Edited by Cem to correct + and - mistake
 
Last edited by a moderator:

Cem_Usakligil

Well-known member
...So to get back to the face , and not any crazy angle just a straight up angle , then when having the micro adjustment at 3+ and aiming the eye , the lips come in focus , so the lens is BF , correct or not ? ^^
No, this is front focus as the lens is focusing in front of the target focus plane.

..Add + value to correct ?
Yes indeed.

As Nicolas wrote, it doesn't matter what you call it, using Bart's method you can get it in focus. I did not refer you to that thread myself since I was under the impression that you may have read it already. It is the second most read thread of all times in OPF ;-)

Cheers,
 

Cem_Usakligil

Well-known member
Hi Ralph,

I am now confused myself as I may have gotten the whole thing the other way around citing from memory. I will go an test now and come back in 10 mins. Sorry.

Cheers,
 

Cem_Usakligil

Well-known member
Hi Ralph,

I am now confused myself as I may have gotten the whole thing the other way around citing from memory. I will go an test now and come back in 10 mins. Sorry.

Cheers,
Yes I was totally confused as I thought that + brought the focus forward but it is the opposite. I have edited all my mistaken posts right away. My apologies.

Cheers,
 
Yes I was totally confused as I thought that + brought the focus forward but it is the opposite.

I initially also had some difficulty in grasping the - or + labeling effect without further reasoning.

I now just think of it in terms of; + will increase the resulting AF distance, and - will reduce the AF distance. Much simpler than using terms of front- and backfocus, and figuring what the AFMA offset is going to achieve.

Bart
 

Ralph Honsbeek

New member
If you could indulge please ,

I just picked up a 5D mark II and my lenses are all on the soft side on AF

For example my 70-200mm F2.8 L USM IS and set the micro adjustments to +20 and took
some portraits (faces). Now I always aim for the eyeball (nice and shiny ^^) or right between the eyes. Now i expected the eyes to be crisp in focus but found that the skin right in front of the eye socket (dark cycle area) or close to the nose is much crisper.

And in the case of my 24-70 I set it to +2 and aimed for the bridge of the nose (not intentionally) but I noticed that the (more deeper lying/ farther away) edges of the eyes were crisp.
So can it be said that the lens is in this case back focusing?

So I find myself yet again confused on how to reset the microadjustments. Do I reduce to less + value or go to Canon Service Center ^^. The reason I set it to +20 (maximum) is because at standard (0) micro adjustments the result was despicable.

I found that my 24-70 and other lenses were showing all similar soft results ...
I wish to resolve the issues with microadjustments if possible ..

thank in advance for the feedback

Ralph
 

Asher Kelman

OPF Owner/Editor-in-Chief
First get manual focus right!

First, Ralph, do you have any correction for your eyes? The green letters and scale in the viewfinder, (not the scene for now) should be made sharp by adjusting the tiny wheel to the upper right. Only when that's tack sharp can you use the viewfinder to judge focus. Use manual now and see if you can get images sharp. Also press the button to the left of your viewfinder to get Live View. With the camera on a tripod, you should be able to take very good pictures. If the images are still blurry, then it's lkely the lens needs checking.

For adjusting micro-focus for the autofocus function of the lens and camera combination, OTOH, the best person is Bart! Read his thread.

Asher
 
If you could indulge please ,

I just picked up a 5D mark II and my lenses are all on the soft side on AF

Hi Ralph,

No problem. It's important to get the best focus exactly where you want it. Afterall, the photographer envisions the effect, and it shouldn't be riddled with nasty surprises. One does need to understand that the out of the camera results can look a bit softer than from DSLRs with fewer pixels than what the 5D2 offers.

For example my 70-200mm F2.8 L USM IS and set the micro adjustments to +20 and took
some portraits (faces). Now I always aim for the eyeball (nice and shiny ^^) or right between the eyes. Now i expected the eyes to be crisp in focus but found that the skin right in front of the eye socket (dark cycle area) or close to the nose is much crisper.

Okay, if you have followed the instructions, and you on average come closest to predictable focus at +20, it seems that the combination of your camera body calibration and the factory lens calibration cannot be micro-adjusted enough. That would suggest that a camera service calibration is in order. Do note that there can/will be different optimal AFMA settings at different focal lengths. Perform AFMA at the most used focal length of a zoom lens, or the longer FL of the range.

And in the case of my 24-70 I set it to +2 and aimed for the bridge of the nose (not intentionally) but I noticed that the (more deeper lying/ farther away) edges of the eyes were crisp.

Well, +2 on the 24-70 suggests a modest correction, so it seems that your 70-200mm is more likely to be off than the camera body (but both might still need calibration). Nevertheless, people often underestimate the DOF that can be discriminated on a 21MP DSLR sensor, and short distances are even more critical. Focuing on the bridge of the nose will give you just that, focus on the bridge of the nose. The eyes/sockets are most likely significantly behind that focal plane. So if you get better focus behind the nose of the bridge which you are focusing on, then you'd need to set the AFMA to a relatively lower (relatively more minus) value.

Portraits are special in the sense that one may prefer to deviate from a normal AFMA optimization. When focusing on a certain facial feature is generally easier than focusing on the eye itself, then one might want to include an appropriate additional offset to the AFMA.

Do make sure that "focus-and-recompose" doesn't play a role in your method of focusing though.

So I find myself yet again confused on how to reset the microadjustments. Do I reduce to less + value or go to Canon Service Center ^^. The reason I set it to +20 (maximum) is because at standard (0) micro adjustments the result was despicable.

Again, +20 would suggest a potentially too deviant a calibration to allow user adjustment. I do assume you've tried several other settings and found that anything less than +20 is worse.

I found that my 24-70 and other lenses were showing all similar soft results ...
I wish to resolve the issues with microadjustments if possible .

Ralph, you seem to have settled for +2 on the 24-70. Was that the best setting, but you still think it is soft, or are you not certain that +2 is best?

Again, high MPixel cameras require different per pixel sharpening/processing even though they exhibit higher absolute resolution. So do make sure that +2 is the best that can be achieved. Then we can look at the postprocessing requirements to get the most of the best focus results.

Cheers,
Bart
 

Ralph Honsbeek

New member
Hi Ralph,
No problem. It's important to get the best focus exactly where you want it. Afterall, the photographer envisions the effect, and it shouldn't be riddled with nasty surprises. One does need to understand that the out of the camera results can look a bit softer than from DSLRs with fewer pixels than what the 5D2 offers.
of course , canon is one of the best if not the best in camera optics and camera bodies , I know I can get better results that's why I am working hard to resolve these issues so I can continue enjoying my new camera.

Well, +2 on the 24-70 suggests a modest correction, so it seems that your 70-200mm is more likely to be off than the camera body (but both might still need calibration). Nevertheless, people often underestimate the DOF that can be discriminated on a 21MP DSLR sensor, and short distances are even more critical. Focuing on the bridge of the nose will give you just that, focus on the bridge of the nose. The eyes/sockets are most likely significantly behind that focal plane. So if you get better focus behind the nose of the bridge which you are focusing on, then you'd need to set the AFMA to a relatively lower (relatively more minus) value.
I am currently trying out some other settings , please stand by for results .


Portraits are special in the sense that one may prefer to deviate from a normal AFMA optimization. When focusing on a certain facial feature is generally easier than focusing on the eye itself, then one might want to include an appropriate additional offset to the AFMA.
Not sure what you are meaning here , but aiming the eyes is key in a beautiful facial

Do make sure that "focus-and-recompose" doesn't play a role in your method of focusing though.
It isn't , straight point and shoot

Again, +20 would suggest a potentially too deviant a calibration to allow user adjustment. I do assume you've tried several other settings and found that anything less than +20 is worse.
I tried out something in between today +11 +12 but not really good ... so so frustrating

Ralph, you seem to have settled for +2 on the 24-70. Was that the best setting, but you still think it is soft, or are you not certain that +2 is best?
Well apparently +2 is not , so I have to try out on some live subjects this week in the negative range



Thanks,
Ralph
 

Ralph Honsbeek

New member
Hello everyone ,

I hope everyone is having a cool summer , it hard to do so over here .

Just to come back to the Micro Adjustment thread I opened a couple of weeks back , I find myself

yet again feeling a lot of unneeded nerve ends flaring up , trying to calibrate perfect sharpness from my

70-200 mm f2.8 IS USM .

I had to take it to Canon Service center for AF calibration after having it on my 5d Markii , it was just

to much of par. Now that I got it back the first time , they did a lousy job and had to bring it back for

a second time. Now they seem to have gotten close but not near perfect sharpness. I feel in my

bones that I can get it sharper and after using the micro adjustment help thread from Bart , and that

moire gif file , I found that they hadn't ...


With tripod and enough distance from the moire image on my laptop , I set up the camera in AF I

shoot at the screen and then checked the results. By going in Liveview mode and switching to MF (in

order to zoom in the LCD), I find that Service Center Factory setting is slightly off, but enough to give

me a rotten feeling about the photos that are resulting from this. I do not get a crisp Moire

effect and have to move the focus ring (no here comes my question ^^) to the right/left in order to

find that perfect crisp Moire , we are all looking for.


Now for my initial question for today , comes yet again the question of moving to the right or to the

left. Let's say I have the lens back from Service and they calibrated it to "0" micro adjustments , but

was in fact not perfect. I would use the AF on the Moire and find not perfect crisp image , and would

turn the focus ring to the RIGHT in order to get perfect sharpness , should I set micro to

+(backward) or -(forward) in the camera settings ... and vice versa when I have to turn the focus

ring
to the LEFT, what would that mean for the direction of micro adjustments in settings ?

It is impossible for me to determine if the lens is in fact Front Focusing or Back Focusing.

Thanks for now and thanks for your patience

Ralph (Seoul Korea)

PS , I have been trying out , but got some sharp results at +2 micro , but after trying again , I now

get a sharp result at -2 micro , weird don't you think ?
 

Asher Kelman

OPF Owner/Editor-in-Chief
Ralph,

You are having fun! but it's important to get the best out if one's gear and focus is at the top! You have me very interested in Bart's reply!

What pictures have you shot? Did they sharpen up well or where you only upset when you did the ultimate Moiré test and saw it was still off? It would be great to see how bad this might be! Can you share some of the pictures?

Asher
 

Ralph Honsbeek

New member
I am talking about millimeter , maybe even less than that , but I am able to notice the difference

When I shot a face and aim the eyes , I expect the eye to be crystal and not other features (more deeper or shallower) on the face to be more in focus.

I was just needing to know when turning right the focus ring , to either plus or minus the Micro Adjustments , and vice versa ,

I could upload some of my photos , but you won't be able to criticize unless you have that Canon application which shows the AF point , forgot the name of it
 
With tripod and enough distance from the moire image on my laptop , I set up the camera in AF I

shoot at the screen and then checked the results. By going in Liveview mode and switching to MF (in

order to zoom in the LCD), I find that Service Center Factory setting is slightly off, but enough to give

me a rotten feeling about the photos that are resulting from this. I do not get a crisp Moire

effect and have to move the focus ring (no here comes my question ^^) to the right/left in order to

find that perfect crisp Moire , we are all looking for.

Hi Ralph,

First, the moiré can show in different ways. Sometimes it's clear and obtrusive, while at other times it's subtle and colorful. How it looks depends on the shooting distance and lens quality at its widest aperture.

There are basically 2 modes of operation, either (A) first do AF and then check in Live View (as you did) whether you can improve the visibility of moiré, or (B) first do a manual focus and then watch how the focus ring moves when doing AF.

(A) The drawback of doing AF first is that you won't know in advance whether to focus closer or farther in Live View to improve focus. However, you have a 50% chance of getting it right the first time ;-) If you guessed wrong, it was the other way.
(B) The drawback of first doing a Live View and then an AF is that you need to watch the focus distance indicator on the lens very closely, and how well that shows depends very much on the travel distance of the focus ring at the focus distance you use. It is easier if you have access to the focus indicator (not hidden behind a window), because you can use 2 small pieces of a Post-it note on the tube and ring with a mark on it, which makes it easier to see a Vernier scale difference.

In your case method (A) is probably the easiest to use, as you did.

Now for my initial question for today , comes yet again the question of moving to the right or to the

left. Let's say I have the lens back from Service and they calibrated it to "0" micro adjustments , but

was in fact not perfect. I would use the AF on the Moire and find not perfect crisp image , and would

turn the focus ring to the RIGHT in order to get perfect sharpness , should I set micro to

+(backward) or -(forward) in the camera settings ... and vice versa when I have to turn the focus

ring
to the LEFT, what would that mean for the direction of micro adjustments in settings ?

Now, how to translate the focus ring movements or distance corrections to an AFMA value? The easiest way to think about it is that it's the AF distance that you want to correct. So if you need the AF to focus closer, then you use a relatively lower value than you currently have. If you need the AF to focus farther away, then you relatively increase the value you currently have. The absolute number is not so important, as long as you can adjust within the adjustment range given. The difference that 1 AFMA value makes depends on the camera type and widest aperture.

So when you have to turn the focus ring clockwise, as seen from behind the camera, you are focusing closer (on a Canon, Nikon is the other way), so you must decrease the AFMA value. If you have to turn the focus ring anti-clockwise, as seen from behind the camera, you are focusing farther away, so you need to increase the AFMA value.

It is impossible for me to determine if the lens is in fact Front Focusing or Back Focusing.

When you need to increase the AF distance manually, you are front focusing, and vice-versa.

PS , I have been trying out , but got some sharp results at +2 micro , but after trying again , I now

get a sharp result at -2 micro , weird don't you think ?

Perhaps it is, but perhaps it isn't, it depends on what you are focusing on. Do remember that the actual focus sensor is larger than the indicator in the viewfinder suggests. It is also easier to focus on high contrast features than on low contrast ones, especially when there is little ambient light. Also, AF isn't perfect so what matters is the on average performance. If there is a general bias towards front or back focusing then you correct it with a higher or lower AFMA value.

Cheers,
Bart
 
Some samples I took with + 6 Macro before second service .
The girl was suspended and her face did not move for seconds , just took these shots and haven't a

clue what happened to the focus. I aimed dead on her eyes/between the eyes/ general facial area.

Nothing in the face is clear/sharp ...

Hi Ralph,

Due to the size of the images it's impossible to judge, could you post a crop of say her right eye and the headscarf to add some depth to judge?

Cheers,
Bart
 
Top