Ok, so I can open these images in LR2 or something, and keep the camera profile set to ACR? Is this what you're saying?
Sorry, kinda a PP NOOB.
Not quite - ACR is the RAW converter for Photoshop. LR2 has something similar embedded within it. So, to answer the question you really meant to ask, you can open your file in LR2 and do much the same thing.
To the best of my knowledge, there's no such thing as "keep(ing) the camera profile set to ACR". ACR is just a tool, not data of any sort.
Not quite - ACR is the RAW converter for Photoshop. LR2 has something similar embedded within it. So, to answer the question you really meant to ask, you can open your file in LR2 and do much the same thing.
To the best of my knowledge, there's no such thing as "keep(ing) the camera profile set to ACR". ACR is just a tool, not data of any sort.
Thanks. Got it I think now.
Oh, I see the difference, I miss read something apparently.
Ok. So I took my 9 shots, loaded them into PS (I did this by clicking File>Open then selected all 9 photos). Here is where I am:
I'm lost on a couple of things. How do I turn the sharpening off? I know how to zoom to 100%, but how do I crop exactly the inner 98% of the image? And is this 98% of the entire image? Or only what I can see on my monitor at 100%?
Ok. So I took my 9 shots, loaded them into PS (I did this by clicking File>Open then selected all 9 photos). Here is where I am:
I'm lost on a couple of things. How do I turn the sharpening off? I know how to zoom to 100%, but how do I crop exactly the inner 98% of the image? And is this 98% of the entire image? Or only what I can see on my monitor at 100%?
1. Move the top three sliders all the way to the left.
2. Bottom left, where it says 12.5%, that's a dropdown, select 100%. This should zoom you view to the very center of the shot, at 100%.
3. Don't understand the question about 98%. Please restate the question.
3. Don't understand the question about 98%. Please restate the question.
How do I tell it to crop the inner 98% of the image? What I tried doing, but haven't saved it yet, is click the crop tool and hold to select my own custom crop size. I found what 98% of both 8" and 12" was, and entered those numbers in. I'm guessing that is inncorrect, hence why I haven't saved my JPEGs yet.
Also, you state to save the JPEGS as "high" quality...is there a reason not to select "Maximum" as that is an option?
How do I tell it to crop the inner 98% of the image? What I tried doing, but haven't saved it yet, is click the crop tool and hold to select my own custom crop size. I found what 98% of both 8" and 12" was, and entered those numbers in. I'm guessing that is inncorrect, hence why I haven't saved my JPEGs yet.
Also, you state to save the JPEGS as "high" quality...is there a reason not to select "Maximum" as that is an option?
Thank you so much for the instant reply btw...
Yeah...I didn't feel like going outside right now, although it is a beautiful day. But it has plenty of depth and contours...
To get a 100% crop import into PS. Set your crop tool to specific number of pixels, say 800 x 800. Drag for your crop, save the result as a file.
As for the quality - for these purposes, high is good enough. Maximum is over-kill for this purpose.
I selected a tree for the texture and also because the curvature of the trunk is predictable - helps in determining the direction and degree to which the AF is out of "zeroed in".
I selected a tree for the texture and also because the curvature of the trunk is predictable - helps in determining the direction and degree to which the AF is out of "zeroed in".
Gotchya, that makes sense. Maybe I'll go outside and do that. I think we have trees in Oregon...
Would it be better, worse, the same to use a ruler and focus on a specific spot on the ruler? Would there be any benefit to doing it that way? Something with maybe mm marks on it so you can see in even more detail?
Would it be better, worse, the same to use a ruler and focus on a specific spot on the ruler? Would there be any benefit to doing it that way? Something with maybe mm marks on it so you can see in even more detail?
Opinions differ on that. My position is that for AF Microadjustment purposes, we want as much light on the subject as we can get to take lens hunting out of the equation as much as possible. Besides, putting the ruler at a slant it's hard to get a decent angle and sufficient distance both at the same time.
Opinions differ on that. My position is that for AF Microadjustment purposes, we want as much light on the subject as we can get to take lens hunting out of the equation as much as possible. Besides, putting the ruler at a slant it's hard to get a decent angle and sufficient distance both at the same time.
Roger. Did some testing and fount out exactly that. Off to the trees I go. Thank you so much. Now I just need to be able to see the subtle differences between -1 and -2, or whatever the case may be.
Second time testing this and feeling like I am on a witch hunt. I have both a 50 f/1.4 and 70-200 2.8 IS. First test was a tape measure and aiming down at it, Decided that no adjustment needed both lenses.
After re-reading tried again outside using a brick wall, again I am thinking results are great with no adjustment. I just really want to be able to dial in a lens i think. Want to adjust it too much i think therefore the witch hunt.
Second time testing this and feeling like I am on a witch hunt. I have both a 50 f/1.4 and 70-200 2.8 IS. First test was a tape measure and aiming down at it, Decided that no adjustment needed both lenses.
After re-reading tried again outside using a brick wall, again I am thinking results are great with no adjustment. I just really want to be able to dial in a lens i think. Want to adjust it too much i think therefore the witch hunt.
Phooey on you guys
Not all lenses and/or bodies need the adjustment. Your stuff might just be dialed in fine from the factory. The same lens on different bodies can be different, as well as the same body on different lenses. If your stuff is checking out fine, then right on. No adjustment needed.
Not all lenses and/or bodies need the adjustment. Your stuff might just be dialed in fine from the factory. The same lens on different bodies can be different, as well as the same body on different lenses. If your stuff is checking out fine, then right on. No adjustment needed.
- If your lenses look right with no adjustment, then ... maybe .... no adjustment is necessary. It could happen. It's been happening for years and years with thousands (millions?) of dSLRs before AF Microadjustment ever hit the street.
Like the old man says, "It if ain't broke, don't fix it!"
I have a 1d Mk III that also allows for AF microadjustment, and I came across a thread here for a reasonably affordable product that's meant to make the process even more precise, particularly if one lacks such a photogenic tree in the back yard. The link is www.rawworkflow.com; mine shipped today and I should have it later this week. I am NOT endorsing it as an alternative to your method (not yet anyway), but it was glowingly endorsed by sources whose opinions matter to me (Luminous Landscape for one) so I am optimistic.
Apparently this device can also be rented, which I learned after placing my order; that's probably worth considering.
That's an interesting device. Before I read your thread I was thinking of maybe typing out some numbers or letters on a piece of paper and angling it obliquely for my test shots. I'd be interested to know how it works for you. One thing I didn't understand after looking at their site is, are the numbers on their board calibrated to the level of correction? For example, if at "0" you focus on the number "0" but "1" turns out to be the sharpest number does that mean you set your AF correction to -1?
That's an interesting device. Before I read your thread I was thinking of maybe typing out some numbers or letters on a piece of paper and angling it obliquely for my test shots. I'd be interested to know how it works for you. One thing I didn't understand after looking at their site is, are the numbers on their board calibrated to the level of correction? For example, if at "0" you focus on the number "0" but "1" turns out to be the sharpest number does that mean you set your AF correction to -1?
That's an interesting device. Before I read your thread I was thinking of maybe typing out some numbers or letters on a piece of paper and angling it obliquely for my test shots. I'd be interested to know how it works for you. One thing I didn't understand after looking at their site is, are the numbers on their board calibrated to the level of correction? For example, if at "0" you focus on the number "0" but "1" turns out to be the sharpest number does that mean you set your AF correction to -1?
The post of mine to which you responded was an old one, and I've had the device for quite some time now. As Kdog stated, the numbers are arbitrary and provide no direct guidance on what adjustment needs to be made in the camera. That's purely a trial-and-error process involving doing a lot of tweaks while you are set up, then looking at the shots on your monitor to see which one worked best. I can report that I like the device, and it is probably incrementally more accurate than homemade alternatives, but the process is kind of a pain in the neck, especially if you're doing multiple lenses. Nevertheless, AF microadjustment can make a HUGE difference to your keeper rate, so the effort is well worth it.
So, is this device really anthing more helpful than leaning a ruler at an incline (as close to 45'deg as I can) and shooting it? I guess the device ensures that I'm shooting at exactly 45 degrees but the main thing is the focus at the center point, so does some variance on the angle really matter?
So, is this device really anthing more helpful than leaning a ruler at an incline (as close to 45'deg as I can) and shooting it? I guess the device ensures that I'm shooting at exactly 45 degrees but the main thing is the focus at the center point, so does some variance on the angle really matter?
The 45 degree angle is not important. In fact, the LensAlign allows you to choose a variety of angles. What is important is that you get a focus lock on where you think you're getting one. The problem with shooting a ruler is that you can't be certain where you actually locked focus. What you really want is a big high-contrast flat target that's exactly parallel with your image sensor, and placed next to a slanted ruler. The 0 mark on the ruler has to be on the exact same plane as the focus target. The LensAlign has some mechanisms built-in so you get that alignment with the least amount of fuss. There's no magic there, it just saves time.
That was what I was wondering about the tree trunk mechanism, but I guess if the bark isn't too fine, you just remember which chunk is your primary edge. I'm getting it now. Thanks. So the indoor method might be something like a stiff board with some high contrast mark on one side and lots of ruler-like marks on the other so you know you focused on the one line and then you can look at all the little marks to see where the best focus is. THe little focusing gizmo is pretty cool though.
Ok, this is where I interject a picture of my home-made focus tester that served me well.
Notice that there's a slanted rule on both sides of the flat focus target. You know the horizontal alignment is correct when both sides agree. Vertical alignment is easier. Just make sure the focus target is vertical, and that your camera is perfectly horizontal on your tripod (so that the sensor is vertical.) Set the height of the tripod so that the lens is centered on the focus target and you're good to go. :whew
(Although, truth be told I recently bought the LensAlign.)
Is it better to be a long distance ( >50 feet ) for a telephoto lens, or a medium distance ( 15 - 20 feet ), or even nearer ( 5 - 10 feet). Does this have any effect on how the lens focuses at a different set of distances then?
I ask these questions because I do not know the answers, nor even where to begin to find the answers.
Good questions, Jim. I don't actually know, but that won't stop me from expressing my opinions on the matter. :giggle
I don't think the distance from the focus target matters much. My guess is that a lens that front focuses does so regardless of the distance to the subject. Let's say for the sake of argument that the amount of the error changes with distance. As long as you dial in the lens at a particular distance, it should still be dialed in at other distances as well. The amount of error might change, but the zero-point of perfect focus should be the same regardless. I haven't heard of lenses that are sharper at one distance than at another, have you?
Now a larger question is for zoom lenses, what focal length do you calibrate at? You do hear of lenses that are sharper at some focal lengths than others. The Canon 16-35 MKII is one such lens. It's sharpest at the wider end. Evidently the MKI version of this lens was sharper on the longer end. So you could turn your MKII into a MKI by calibrating it for the long end. Doesn't sound like a good tradeoff. So choose wisely.
Update: Tools I'm using now
The following is intended as an update to the information in the originating post.
First, I was having problems with reproducability using the technique outlined in the first post; the adjustment factors were moving all over the available range. OK, maybe that's a little strong, but they were moving 3 or 4 points and that's just plain wrong. I attribute it to two factors:
The consistancy with which the camera was able to focus on the exactly the same spot each time. It can be easily argued that the chances of that happening are quite small.
The consistancy with whihc I am able to pick the best image - even less then the above
So, I looked around and came to understand the principle(s) behind the LensAlign tool. Not wanting to pay the $90 or more for a copy of one of these tools, I decided to take some scrap wood I have around the place (we're building an addition and the contractors have left a lot of scrap in the dumpster - I love dumpster diving!) I built this:
What you see here is
A high-contrast focusing target (the printed paper) mounted (with cellophane tape) to a small piece of wafer board.
There's a cut on the camera-right side into which is slide another piece of wafer board - at an approximate 45° angle to the veritical.
Because my carpentry skills aren't what I would like, the 45° piece isn't long enough to reach the level surface and still keep the vertical board .... well, vertical. So, there's a block made from a bunch of small pieces of wafer board nailed together to bring everything into square.
The ruler is taped to the 45° board with duct tape (very high-tech this thing is ) with the 8" mark aligned with the front surface of the vertical board - thus on the same focus plane.
Coming out of the upper left corner is a 50W halogen lamp to supply sufficient light onto the focuing target.
The whole arrangement is set up on a piece of cardboard on top of a stool - the carboard is needed because the stool surface is not large enough to hold the tool.
This is a shot of the setup in use (don't even ask what all that stuff is on the right side of the room ):
The AlienBee on the right side is there to proved a good exposure as the 50W light is not nearly enough to do the job. I'm using the ceiling of the room (which just happens to be white) to provide diffusion.
BTW - the above shot was take with my new 5D2 at ISO 800 while setup to check the adjustment of my 50D/70-200 combination. I think I'm really like the way the 5D2 handles high ISO
The result of this set up is something that looks like this:
Zoomed in 1:1 in Lightroom, and using the compare feature, allows one to quickly and easily select the best shot of the series (see first post).
Total cost? Well the wood was free. The paper is very cheap. Probably the most expensive component of the entire device is that piece of duct tape - all the rest I already had in house.
The nit here is still the coplanarity of the rig and the sensor, which shouldn't be a huge deal, right? The ruler really only helps guide you in which direction to go and how much to go. If the center of the image you are focused on is dead on, then you are okay (provided you are shooting with your lens wide open), and close enough that your DOF is nearly zero. I was trying to do this the other day with my daughters webkinz toys, but had to punt because nothing seemed tack sharp SOOC at any setting, which has me wondering if there is something else amiss. With a little sharpening, everything is crisp, but not SOOC. My next experiement is to see what variance there is between different lenses at 70mm (common focal length).
The nit here is still the coplanarity of the rig and the sensor, which shouldn't be a huge deal, right? The ruler really only helps guide you in which direction to go and how much to go. If the center of the image you are focused on is dead on, then you are okay (provided you are shooting with your lens wide open), and close enough that your DOF is nearly zero. I was trying to do this the other day with my daughters webkinz toys, but had to punt because nothing seemed tack sharp SOOC at any setting, which has me wondering if there is something else amiss. With a little sharpening, everything is crisp, but not SOOC. My next experiement is to see what variance there is between different lenses at 70mm (common focal length).
Given the (assumed on my part) compromises made in the design of our lenses, I would think the deviation from co-planarity between that of the sensor and my (or your) rig would induce only the very smallest of errors; errors small enough that they would probably be not much more than noise.
In my rig, the ruler serves to purposes. The first is, as you say, an indicator of which way things are off. The second is also to help judge which is the best between two good shots; these some very fine printing on the ruler at the 8" mark that is close enough to the plane of the focusing target that it is useful as a discriminator. Even better would be to include some very fine printing in the center of the focusing target - which I'll do in Ver 2.0 of that target . Thanks for helping me move in the right direction with that.
As for the sharpness SOOC, yup ... RAW files will lack a bit in sharpness due to a number of factors, not the least of which is the AA filter mounted in the light path between the sensor and your subject.
I was helping a friend of mine who now has a new to her 50D with the AF Microadjustment. We used this rig. After making the indicated adjustment for her 85mm f/1.8 and as a test, she shot quick on of her son (head and shoulders) from about 10 feet away. You know how shows like CSI like to show hair under a microscope so the views are all impressed with seeing the scales of the hair? Well, the photo she got of her son was almost that sharp. She was quite pleased with the results.
Thanks a ton. I wish my eyes were younger for this analysis. If you have the center focus point enabled, do you really need a large/complex target for focus. Won't you just be focusing on the center of your sheet anyhow, or do you want to/need to run this with all focus points enabled?
Thanks a ton. I wish my eyes were younger for this analysis. If you have the center focus point enabled, do you really need a large/complex target for focus. Won't you just be focusing on the center of your sheet anyhow, or do you want to/need to run this with all focus points enabled?
I use the center focus point only when I do this. But, one must understand that the area "looked at" by the focusing mechanism may or may not exactly match the little red square you see in the viewfinder. So, this chart I use may or may not be over-kill. If it is, there's not a lot lost as it only took me about 5 minutes to build that thing. And, since it's all on the same plane, mo' is better.
Comments
Sorry, kinda a PP NOOB.
OneTwoFiftieth | Portland, Oregon | Modern Portraiture
My Equipment:
Bodies: Canon 50D, Canon EOS 1
Lenses: Canon 10-22mm f/3.5-4.5, Canon 24-105mm f/4L IS, Canon 50mm f/1.4, Canon 100mm f/2.8 Macro, Canon MP-E 65mm f/2.8
Lighting: Canon 580EXII, Canon 420 EX, 12" Reflector, Pocket Wizard Plus II (3), AB800 (3), Large Softbox
Stability: Manfrotto 190CXPRO3 Tripod, Manfrotto 488RC4 Ball Head, Manfrotto 679B Monopod
To the best of my knowledge, there's no such thing as "keep(ing) the camera profile set to ACR". ACR is just a tool, not data of any sort.
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Thanks. Got it I think now.
Oh, I see the difference, I miss read something apparently.
OneTwoFiftieth | Portland, Oregon | Modern Portraiture
My Equipment:
Bodies: Canon 50D, Canon EOS 1
Lenses: Canon 10-22mm f/3.5-4.5, Canon 24-105mm f/4L IS, Canon 50mm f/1.4, Canon 100mm f/2.8 Macro, Canon MP-E 65mm f/2.8
Lighting: Canon 580EXII, Canon 420 EX, 12" Reflector, Pocket Wizard Plus II (3), AB800 (3), Large Softbox
Stability: Manfrotto 190CXPRO3 Tripod, Manfrotto 488RC4 Ball Head, Manfrotto 679B Monopod
I'm lost on a couple of things. How do I turn the sharpening off? I know how to zoom to 100%, but how do I crop exactly the inner 98% of the image? And is this 98% of the entire image? Or only what I can see on my monitor at 100%?
OneTwoFiftieth | Portland, Oregon | Modern Portraiture
My Equipment:
Bodies: Canon 50D, Canon EOS 1
Lenses: Canon 10-22mm f/3.5-4.5, Canon 24-105mm f/4L IS, Canon 50mm f/1.4, Canon 100mm f/2.8 Macro, Canon MP-E 65mm f/2.8
Lighting: Canon 580EXII, Canon 420 EX, 12" Reflector, Pocket Wizard Plus II (3), AB800 (3), Large Softbox
Stability: Manfrotto 190CXPRO3 Tripod, Manfrotto 488RC4 Ball Head, Manfrotto 679B Monopod
2. Bottom left, where it says 12.5%, that's a dropdown, select 100%. This should zoom you view to the very center of the shot, at 100%.
3. Don't understand the question about 98%. Please restate the question.
P.S. - that's a funny looking tree!:D
My Photos
Thoughts on photographing a wedding, How to post a picture, AF Microadjustments?, Light Scoop
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Ok. Did that.
Got that part.
How do I tell it to crop the inner 98% of the image? What I tried doing, but haven't saved it yet, is click the crop tool and hold to select my own custom crop size. I found what 98% of both 8" and 12" was, and entered those numbers in. I'm guessing that is inncorrect, hence why I haven't saved my JPEGs yet.
Also, you state to save the JPEGS as "high" quality...is there a reason not to select "Maximum" as that is an option?
Thank you so much for the instant reply btw...
Yeah...I didn't feel like going outside right now, although it is a beautiful day. But it has plenty of depth and contours...
OneTwoFiftieth | Portland, Oregon | Modern Portraiture
My Equipment:
Bodies: Canon 50D, Canon EOS 1
Lenses: Canon 10-22mm f/3.5-4.5, Canon 24-105mm f/4L IS, Canon 50mm f/1.4, Canon 100mm f/2.8 Macro, Canon MP-E 65mm f/2.8
Lighting: Canon 580EXII, Canon 420 EX, 12" Reflector, Pocket Wizard Plus II (3), AB800 (3), Large Softbox
Stability: Manfrotto 190CXPRO3 Tripod, Manfrotto 488RC4 Ball Head, Manfrotto 679B Monopod
As for the quality - for these purposes, high is good enough. Maximum is over-kill for this purpose.
I selected a tree for the texture and also because the curvature of the trunk is predictable - helps in determining the direction and degree to which the AF is out of "zeroed in".
My Photos
Thoughts on photographing a wedding, How to post a picture, AF Microadjustments?, Light Scoop
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Gotchya, that makes sense. Maybe I'll go outside and do that. I think we have trees in Oregon...
OneTwoFiftieth | Portland, Oregon | Modern Portraiture
My Equipment:
Bodies: Canon 50D, Canon EOS 1
Lenses: Canon 10-22mm f/3.5-4.5, Canon 24-105mm f/4L IS, Canon 50mm f/1.4, Canon 100mm f/2.8 Macro, Canon MP-E 65mm f/2.8
Lighting: Canon 580EXII, Canon 420 EX, 12" Reflector, Pocket Wizard Plus II (3), AB800 (3), Large Softbox
Stability: Manfrotto 190CXPRO3 Tripod, Manfrotto 488RC4 Ball Head, Manfrotto 679B Monopod
OneTwoFiftieth | Portland, Oregon | Modern Portraiture
My Equipment:
Bodies: Canon 50D, Canon EOS 1
Lenses: Canon 10-22mm f/3.5-4.5, Canon 24-105mm f/4L IS, Canon 50mm f/1.4, Canon 100mm f/2.8 Macro, Canon MP-E 65mm f/2.8
Lighting: Canon 580EXII, Canon 420 EX, 12" Reflector, Pocket Wizard Plus II (3), AB800 (3), Large Softbox
Stability: Manfrotto 190CXPRO3 Tripod, Manfrotto 488RC4 Ball Head, Manfrotto 679B Monopod
My Photos
Thoughts on photographing a wedding, How to post a picture, AF Microadjustments?, Light Scoop
Equipment List - Check my profile
Roger. Did some testing and fount out exactly that. Off to the trees I go. Thank you so much. Now I just need to be able to see the subtle differences between -1 and -2, or whatever the case may be.
Thanks so much.
OneTwoFiftieth | Portland, Oregon | Modern Portraiture
My Equipment:
Bodies: Canon 50D, Canon EOS 1
Lenses: Canon 10-22mm f/3.5-4.5, Canon 24-105mm f/4L IS, Canon 50mm f/1.4, Canon 100mm f/2.8 Macro, Canon MP-E 65mm f/2.8
Lighting: Canon 580EXII, Canon 420 EX, 12" Reflector, Pocket Wizard Plus II (3), AB800 (3), Large Softbox
Stability: Manfrotto 190CXPRO3 Tripod, Manfrotto 488RC4 Ball Head, Manfrotto 679B Monopod
Second time testing this and feeling like I am on a witch hunt. I have both a 50 f/1.4 and 70-200 2.8 IS. First test was a tape measure and aiming down at it, Decided that no adjustment needed both lenses.
After re-reading tried again outside using a brick wall, again I am thinking results are great with no adjustment. I just really want to be able to dial in a lens i think. Want to adjust it too much i think therefore the witch hunt.
Phooey on you guys
Not all lenses and/or bodies need the adjustment. Your stuff might just be dialed in fine from the factory. The same lens on different bodies can be different, as well as the same body on different lenses. If your stuff is checking out fine, then right on. No adjustment needed.
OneTwoFiftieth | Portland, Oregon | Modern Portraiture
My Equipment:
Bodies: Canon 50D, Canon EOS 1
Lenses: Canon 10-22mm f/3.5-4.5, Canon 24-105mm f/4L IS, Canon 50mm f/1.4, Canon 100mm f/2.8 Macro, Canon MP-E 65mm f/2.8
Lighting: Canon 580EXII, Canon 420 EX, 12" Reflector, Pocket Wizard Plus II (3), AB800 (3), Large Softbox
Stability: Manfrotto 190CXPRO3 Tripod, Manfrotto 488RC4 Ball Head, Manfrotto 679B Monopod
Like the old man says, "It if ain't broke, don't fix it!"
My Photos
Thoughts on photographing a wedding, How to post a picture, AF Microadjustments?, Light Scoop
Equipment List - Check my profile
That's an interesting device. Before I read your thread I was thinking of maybe typing out some numbers or letters on a piece of paper and angling it obliquely for my test shots. I'd be interested to know how it works for you. One thing I didn't understand after looking at their site is, are the numbers on their board calibrated to the level of correction? For example, if at "0" you focus on the number "0" but "1" turns out to be the sharpest number does that mean you set your AF correction to -1?
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Nope, the numbers are simply an arbitrary scale.
Link to my Smugmug site
Cool, that's what I figured. I constructed a DIY scale of numbers and hopefully later this week will do some adjusting and post what I have.
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The 45 degree angle is not important. In fact, the LensAlign allows you to choose a variety of angles. What is important is that you get a focus lock on where you think you're getting one. The problem with shooting a ruler is that you can't be certain where you actually locked focus. What you really want is a big high-contrast flat target that's exactly parallel with your image sensor, and placed next to a slanted ruler. The 0 mark on the ruler has to be on the exact same plane as the focus target. The LensAlign has some mechanisms built-in so you get that alignment with the least amount of fuss. There's no magic there, it just saves time.
Link to my Smugmug site
Who is wise? He who learns from everyone.
My SmugMug Site
Notice that there's a slanted rule on both sides of the flat focus target. You know the horizontal alignment is correct when both sides agree. Vertical alignment is easier. Just make sure the focus target is vertical, and that your camera is perfectly horizontal on your tripod (so that the sensor is vertical.) Set the height of the tripod so that the lens is centered on the focus target and you're good to go. :whew
(Although, truth be told I recently bought the LensAlign.
Link to my Smugmug site
Is it better to be a long distance ( >50 feet ) for a telephoto lens, or a medium distance ( 15 - 20 feet ), or even nearer ( 5 - 10 feet). Does this have any effect on how the lens focuses at a different set of distances then?
I ask these questions because I do not know the answers, nor even where to begin to find the answers.
Moderator of the Technique Forum and Finishing School on Dgrin
I don't think the distance from the focus target matters much. My guess is that a lens that front focuses does so regardless of the distance to the subject. Let's say for the sake of argument that the amount of the error changes with distance. As long as you dial in the lens at a particular distance, it should still be dialed in at other distances as well. The amount of error might change, but the zero-point of perfect focus should be the same regardless. I haven't heard of lenses that are sharper at one distance than at another, have you?
Now a larger question is for zoom lenses, what focal length do you calibrate at? You do hear of lenses that are sharper at some focal lengths than others. The Canon 16-35 MKII is one such lens. It's sharpest at the wider end. Evidently the MKI version of this lens was sharper on the longer end. So you could turn your MKII into a MKI by calibrating it for the long end. Doesn't sound like a good tradeoff. So choose wisely.
Cheers,
-joel
Link to my Smugmug site
The following is intended as an update to the information in the originating post.
First, I was having problems with reproducability using the technique outlined in the first post; the adjustment factors were moving all over the available range. OK, maybe that's a little strong, but they were moving 3 or 4 points and that's just plain wrong. I attribute it to two factors:
- The consistancy with which the camera was able to focus on the exactly the same spot each time. It can be easily argued that the chances of that happening are quite small.
- The consistancy with whihc I am able to pick the best image - even less then the above
So, I looked around and came to understand the principle(s) behind the LensAlign tool. Not wanting to pay the $90 or more for a copy of one of these tools, I decided to take some scrap wood I have around the place (we're building an addition and the contractors have left a lot of scrap in the dumpster - I love dumpster diving!) I built this:What you see here is
- A high-contrast focusing target (the printed paper) mounted (with cellophane tape) to a small piece of wafer board.
- There's a cut on the camera-right side into which is slide another piece of wafer board - at an approximate 45° angle to the veritical.
- Because my carpentry skills aren't what I would like, the 45° piece isn't long enough to reach the level surface and still keep the vertical board .... well, vertical. So, there's a block made from a bunch of small pieces of wafer board nailed together to bring everything into square.
- The ruler is taped to the 45° board with duct tape (very high-tech this thing is
) with the 8" mark aligned with the front surface of the vertical board - thus on the same focus plane.
- Coming out of the upper left corner is a 50W halogen lamp to supply sufficient light onto the focuing target.
- The whole arrangement is set up on a piece of cardboard on top of a stool - the carboard is needed because the stool surface is not large enough to hold the tool.
This is a shot of the setup in use (don't even ask what all that stuff is on the right side of the roomThe AlienBee on the right side is there to proved a good exposure as the 50W light is not nearly enough to do the job. I'm using the ceiling of the room (which just happens to be white) to provide diffusion.
BTW - the above shot was take with my new 5D2 at ISO 800 while setup to check the adjustment of my 50D/70-200 combination. I think I'm really like the way the 5D2 handles high ISO
The result of this set up is something that looks like this:
Zoomed in 1:1 in Lightroom, and using the compare feature, allows one to quickly and easily select the best shot of the series (see first post).
Total cost? Well the wood was free. The paper is very cheap. Probably the most expensive component of the entire device is that piece of duct tape - all the rest I already had in house.
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Thoughts on photographing a wedding, How to post a picture, AF Microadjustments?, Light Scoop
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In my rig, the ruler serves to purposes. The first is, as you say, an indicator of which way things are off. The second is also to help judge which is the best between two good shots; these some very fine printing on the ruler at the 8" mark that is close enough to the plane of the focusing target that it is useful as a discriminator. Even better would be to include some very fine printing in the center of the focusing target - which I'll do in Ver 2.0 of that target
As for the sharpness SOOC, yup ... RAW files will lack a bit in sharpness due to a number of factors, not the least of which is the AA filter mounted in the light path between the sensor and your subject.
I was helping a friend of mine who now has a new to her 50D with the AF Microadjustment. We used this rig. After making the indicated adjustment for her 85mm f/1.8 and as a test, she shot quick on of her son (head and shoulders) from about 10 feet away. You know how shows like CSI like to show hair under a microscope so the views are all impressed with seeing the scales of the hair? Well, the photo she got of her son was almost that sharp. She was quite pleased with the results.
My Photos
Thoughts on photographing a wedding, How to post a picture, AF Microadjustments?, Light Scoop
Equipment List - Check my profile
Who is wise? He who learns from everyone.
My SmugMug Site
My Photos
Thoughts on photographing a wedding, How to post a picture, AF Microadjustments?, Light Scoop
Equipment List - Check my profile