New 7d & lenses - front/back focussing

I had trully hoped that going with the 7d and getting better quality lenses, I would not have problems with front or back focussing issues. I had the 40d several years ago and left canon due to having to send it in 4x for them to get it right - I had a lemon camera and first repair, 2 weeks after purchase, they said the main board was undervoltaged which caused the focusing problems, but after that they never could get it to work properly. But now I am back to give Canon a chance.

While I haven't taken the camera and lenses out on actual outing (zoo or such), I have noticed a few shots around house and outside not quite up to sharpness I was expecting. Finally pulled focussing chart out and handholding, did some quick tests. Granted the light was inside, so shutter speed was low, it still should give me an idea of what is happening.

The 70-200 f4 IS is backfocussing slightly at 200mm at f4 and 10-15 ft away. Outside I took a picture of the corner of the gazebo across the street (daylight). I noticed the fence behind the gazebo 10 feet back seemed slightly more in focus.

The 15-85 is front focussing quite a bit at 85 at f5.6 and ~ 8 ft away. Most pictures prior with this lens seemed fine, though every now and then I noticed the nose on my girlfriend's cat (semi willingly) seemed sharper than the eyes, which I focussed on and even went into dpp and verified that was the focus mark.

So question: Am I just expecting the quality control of lenses to be reliable and that lenses SHOULD be focused/calibrated correctly? Tired of lenses from Canon never focusing correctly (I will acknowledge the issue I had several years ago most likely was the camera and not the lenses, as Canon even mentioned towards end when I told them no more...though they never offered me a new one, but a refurbished...I refused and returned all to store).

I am within my 30 days of buying camer from Adorama.

• Should I return it to Adorama for an exchange? If so, return what, the lenses only or camera and lenses both?
• Send it in to Canon to have them calibrate?
• Work with MA on the 7D (small part that pulled me away from 60D, but also would prefer to have that feature as a "last resort")

One issue I am facing is I am going up to see girlfriend's family for weekend on Dec 17-19 and know there are some gorgeous landscapes along the way (6+ hour trip, snow permitting) so am also facing that too. If I send it to canon vs Adorama, which one would I get return fastest.

What would you recommend?

My head hurts thinking about this...hate stress.

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• Malathan

Or just send it back .... user error has been dismissed

Going back through all the photos I have taken and test charts (but mostly the photos), I feel the 15-85 is workable, maybe just a little MA adjustment if I want to be anal. The 70-200 f4 IS however does seem to be back focussing or soft in most shots. I found several pictures where shutter was in the 1/500 or greater range, so hopefully ruling out camera shake.

Below is one image, cropped, that shows what I am seeing. The circle is the area I was focussing on. The edge of the gate (~ 15 feet behind) seems sharper, as does the tree even more (~ 25 feet). I took several pictures and all got the same results. 2nd image is a screen grab of dpp raw, unprocessed, showing the focus area (did this after uploading first image).









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• Malathan

What mode did you shoot in? I am have the same issues shooting in Auto or CA. Try using P with spot auto focus and see how the photo turns out.
Gary

Just checked the Raw files, this was in Apeture -Priority. Metering was center weighted. AF was AI Focus with AF area manual selection.
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• Malathan

AI Focus is generally regarded as relatively useless, if not unpredictable. If you're doing a focus test like this one, suggest that you use single shot mode with a single focus point. Spot focus is fine for the sort of testing you're doing, though the example you showed should not have caused an issue with accurate focusing using the standard focus point.

If I had an issue with a single lens or two, but the rest worked well, I'd probably just use MFA to bring the ones with issues into adjustment (which is exactly what I've done in my own case). If it appears to be a problem with a number of lenses, I'd either return the camera for a replacement or send it (and possibly lenses -- Canon will advise you on that) in for service.

malathan said:

Just checked the Raw files, this was in Apeture -Priority. Metering was center weighted. AF was AI Focus with AF area manual selection.
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• Malathan

Click to expand...

"What would you recommend?
My head hurts thinking about this...hate stress."

You are your own worst enemy, or so it appears as you're making mistakes. No tripod or single point focus for starters. This info is readily available, including from Canon, as to how to do MFA testing.
You need to be methodical and test for MFA correctly and patiently.

Here's a place to start:

http://www.northlight-images.co.uk/article_pages/cameras/1ds3_af_micoadjustment.html

Please don't take this the wrong way but these types of posts are why some think MFA is unnecessary, or a myth.

Regarding your landscape images you are anticipating... this is not typically where MFA is a problem as you will be using a short(ish) focal length and probably will be stopped down a bit. I incurred the need to MFA only my two longest lenses, EF400 f5.6 and EF70-200 f4.0. All my shorter lenses were fine and I think this is probably typical.

You are right in that I still have a lot to learn. I have been trying to go through Canon's online training and a book on the 7d.

From what I understand, having the focus points set to manual selection is basically a single point focus. Also, from a tripod standpoint, at 1/1500 second, is it really necessary, especially when taking test images in which you want to as closely simulate real world usage? Rarely (very rarely) will I ever use a tripod, especially at that shutter speed.

corndog said:

You are your own worst enemy, or so it appears as you're making mistakes. No tripod or single point focus for starters. This info is readily available, including from Canon, as to how to do MFA testing.

Click to expand...

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• Malathan

corndog said:

I incurred the need to MFA only my two longest lenses, EF400 f5.6 and EF70-200 f4.0. All my shorter lenses were fine and I think this is probably typical.

Click to expand...

My 70-200/f4 IS is the longest lens I currently own and it seems to be fine although I haven't actually done a full blown focus test with it yet. The rest of my lenses are spot on. I always assume gear issues are caused by me doing something wrong first. And I'm usually right.

It can also be your co-operation with a new camera and AF- system...

You think you focused on that white edge... but it is possible that the focusing point actually is larger than the frame showing the point - and the focusing AF system found more contrast in that green stuff behind it. Sometimes focusing systems can be fooled in such situations

Try focusing on a larger contrasty and flat thing (not an edge) - like some big contrasty toy on a lawn. Then you can see better where the sharp area is. And go closer like 5 meters (shallow DOF) and use f 4 (really shallow DOF with 200mm lens) - easier to judge the focus .

In your image the green tree behind the white edge and part of the roof are sharper. It is possible that the AF system did not read your mind ; )

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Kari
SLR photography started in 1968, 40D since 2007, and now 7D !
60.21 N 24.86 E

To your question as to why to use a tripod for testing... it's really to take other factors out of the equation, like camera shake. Now at 1/1500s you're probably OK from that standpoint, but one absolute requirement for focus testing/calibration is that the camera be perpendicular to the target. When hand holding the camera, it's fairly easy to inadvertently shoot at a bit of an angle, and with large apertures and thin DOF (as you should be using for focus testing), it can completely throw off your test.

Forgive me for repeating something that I've posted quite a bit lately in other threads, but my favorite technique for checking out focus is to use LV focus (contrast detect) as a reference since it works off the actual image from the sensor. Then (and here's where the tripod really helps), you can take the same exact shot again, but this time using single shot standard (phase detect) focus and see if your focus ring moves at all on the lens. If both techniques focus differently on a decent sized, high contrast, perpendicular target... you have a focus issue and should consider MFA to compensate for it. You should also retest at different focal lengths on your zoom lenses to see if the issue is fairly consistent across the range of any given zoom lens. If it isn't, then the lens may need to go back to Canon for calibration.

Hope this helps, again, sorry if I'm overly repeating myself here.

malathan said:

You are right in that I still have a lot to learn. I have been trying to go through Canon's online training and a book on the 7d.

From what I understand, having the focus points set to manual selection is basically a single point focus. Also, from a tripod standpoint, at 1/1500 second, is it really necessary, especially when taking test images in which you want to as closely simulate real world usage? Rarely (very rarely) will I ever use a tripod, especially at that shutter speed.

corndog said:

You are your own worst enemy, or so it appears as you're making mistakes. No tripod or single point focus for starters. This info is readily available, including from Canon, as to how to do MFA testing.

Click to expand...

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• Malathan

Click to expand...

I don't get the questioning. IF after reading one or two of the methods for testing and adjusting MFA, and gone through it, you want to question the methodology, then OK. You'd be wrong, but at least you'd have read it, done it, and then were wrong.

The OP said "He's got a lot to learn". Learn what? This isn't brain surgery. If you can read english and comprehend what you are reading then you do this simple MFA thing. There's no curve to overcome, it's easy.

Seriously folks, try reading.

Well, interpret it as you will but I gave the poster the benefit of the doubt and assumed he simply wanted to better understand why a tripod was needed for testing if it isn't used in typical shooting. I didn't so much take this as challenging the technique but rather trying to better understand it.

And, BTW, all the intricacies of CD vs. PD focus... single shot vs. servo... single point vs. multiple points... spot vs. regular focus points... etc. may seem like brain surgery until you get the hang of it. And even for an experienced shooter, MFA isn't necessarily the easiest thing in the world to do. Again, never hurts to give someone the benefit of the doubt, at least for a while IMHO. I've asked my share of questions when starting out that probably evoked a eye roll or two.

corndog said:

I don't get the questioning. IF after reading one or two of the methods for testing and adjusting MFA, and gone through it, you want to question the methodology, then OK. You'd be wrong, but at least you'd have read it, done it, and then were wrong.

The OP said "He's got a lot to learn". Learn what? This isn't brain surgery. If you can read english and comprehend what you are reading then you do this simple MFA thing. There's no curve to overcome, it's easy.

Seriously folks, try reading.

Click to expand...

corndog said:

The OP said "He's got a lot to learn". Learn what?...

Click to expand...

Sorry, I meant that I have got a lot to learn about photography and the camera in general. I understand the basics, but the actual hands-on is still a struggle. As an example my office had an open house and I got to take pictures (had a choice to be on the backside of the camera vs the front). Using the 15-85 (not best for indoors) some pictures were ok, some not. Several "critical" pictures I took I found afterwards were blurred because I accidentally changed aparture to 9.5, rather than the

...and yes, still at office party. Had to get out of the crowd and hide.

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• Malathan

Jerry-astro said:

Well, interpret it as you will but I gave the poster the benefit of the doubt and assumed he simply wanted to better understand why a tripod was needed for testing if it isn't used in typical shooting. I didn't so much take this as challenging the technique but rather trying to better understand it.

And, BTW, all the intricacies of CD vs. PD focus... single shot vs. servo... single point vs. multiple points... spot vs. regular focus points... etc. may seem like brain surgery until you get the hang of it. And even for an experienced shooter, MFA isn't necessarily the easiest thing in the world to do. Again, never hurts to give someone the benefit of the doubt, at least for a while IMHO. I've asked my share of questions when starting out that probably evoked a eye roll or two.

Click to expand...

Jerry,

I get that you are trying to be helpful. I have no issue with that. What I am saying is that the Canon method, for instance, is self evident. As are others. The reason for the tripod is consistency. You want a high contrast target, like a USAF 1951 resolution chart, and as you go through process you want the single point of focus to be in the same spot EVERY time. This is how you get viable comparisons. BUT, this is explained or is readily apparent once you've read and done it.

Regarding the differences of focus modes and how they work and getting accustomed to them, well... it's all irrelevant. For the purposes of MFA. One only uses single shot, center focus.

I have no problem giving people a certain benefit of doubt, once they've tried something. These forums seem to be filled with people that ask questions without doing a search or reading on their own.

Before I did an MFA on my lenses I had no experience doing it before but after reading through the process it seemed logical and simple and I just did it. It works fine.

malathan said:

• Work with MA on the 7D (small part that pulled me away from 60D, but also would prefer to have that feature as a "last resort")

Click to expand...

I replaced my 7D with 60D. No inconsistent focus problem. No need for any MA either. Happy at last.