Yet another reason to get 50D

Nikolai

I never thought I would actually use this feature... The micro adjustment, that is.
Recently I realized that my focusing is off. At first I thought is was silly old me, but a few hours of experimenting with a ruler, two bodies and three lenses showed pretty reliably it's a camera, and a little bit of one lens, my "workhorse" 17-55, which recently went through repairs). The bottom line was rather solid: it was short focusing by about 1..2 inches at 40 inches distance (slightly less on other lenses). Enough to get the eyes OOF.

I don't know what triggered it, but the effect was there - all my recent shots displayed it rather unambiguously (at least when viewed at 100%). 17-55 displayed it a little bit worse that then other lenses. Also central AF point behaved slightly better than the corner ones (which I use almost exclusively for portrait purposes)

Once I realize this was the hardware problem my first reaction was to prep the camera for shipping and send it to the Canon Repair Center. However, this would mean two weeks with no spare body, and Xmas is pretty hot season. And then it dawned on me...

After few minutes of looking through the menus (and even consulting the manual, p.178 in case you're interested) I found the item: the micro adjustment. Essentially, it allows you to "shift" the focusing point by a certain amount, either for all lenses, for on a lens-by-lens basis. In the last case scenario the camera memorizes the lens automatically (up to 20 different ones) and engages the proper amount of focus shifting when you snap on the specific registered one.

I remembered the whole thing looked a little like a black magic to me when I first read about this new feature, but since I already invested several hours identifying the problem I decided to spend a little bit more time and see if this can help. Surprisingly, it did, and it took far less time than I think it would.

All it takes is a clear focusing target and something like a ruler. The latter doesn't have to have numbers, but it should have some clearly distinctive pattern to tell you where your focus is.
For instance, in this shot I was focusing on the tip of the ball pen located precisely at 30 inch mark.



However, you can clearly see that the sharpest tick marks are around 29 inch mark, or even closer.

The rest is old good trial-and-error method. Set the camera quality to Large jpegs. Take a shot. Play, magnify to the limit. See which direction your focus is. In my case it was short focusing. Go to the Custom Function in question, adjust the point all the way (20 steps max) backward. Take another shot, play, magnify. In my case it took the focus point to the 31" mark. So I moved it to 10 steps, and then repeated the procedure a few times until I ended up with 12 and a tack sharp pen tip. At first the whole thing took me about 30 minutes. Now I can tune up every lens under two minutes - which I did.

Bottom line: I will still send the body for the tune up. But only after the new year. In the mean time I think I'm in a better shape focusing-wise than I have ever been, knowing that my camera knows precisely how to focus each of my lenses to a fraction of an inch. And I intend to repeat this procedure after I get the body back from the store. Who knows, maybe it would need another step or two:-) :wink

HTH

kdog

Great post, Nik. You showed just how easy is it to leverage this important new feature with such a simple set up. There's no need for elaborate test targets and jigs if you use your head.

Question, why do you feel you need to send in your body for a "tune up" if it's focusing correctly now?

Cheers,
-joel

Nikolai

kdog wrote:

Great post, Nik. You showed just how easily is it to leverage this important new feature with such a simple set up. There's no need for elaborate test targets and jigs if you use your head.

Question, why do you feel you need to send in your body for a "tune up" if it's focusing correctly now?

Cheers,
-joel

Thanks, Joel!

Great question... I guess just to be on a safe side. While it's my second 50D body (the very first got too many Error99s, so I got it replaced after the shootout), it's still one of the first ones, so the off-focus can be an indication of something else.

Scott_Quier

I have found that there are a couple of factos to keep in mind when doing an adjustment:

• If possible/sensible, the AF Microadjustment of a zoom lens should be done at closer to your "normal" shooting distance and the focusing distance does impact the adjustment factor a touch. Your focus distance should be a large multiple (5 - 10) of the minimum focusing distance.
• Even more so, the focal length of the lens can impact on the "correct" adjustment factor.

Nikolai

Scott_Quier wrote:

I have found that there are a couple of factos to keep in mind when doing an adjustment:

• If possible/sensible, the AF Microadjustment of a zoom lens should be done at closer to your "normal" shooting distance and the focusing distance does impact the adjustment factor a touch. Your focus distance should be a large multiple (5 - 10) of the minimum focusing distance.
• Even more so, the focal length of the lens can impact on the "correct" adjustment factor.

As to your #1, I did exactly that. I normally shoot at 10-15 ft, and I adjusted at 2-3 ft.

And your #2 is the reason why I eventyually want to have the body "zeroed" back :-)

NeilL

Thanks Nik.

Fascinating, and as exciting as reading Agatha Christie

clemensphoto's

I'm kind of glad I'm waiting to purchase the new 50D until March - hopefully a great deal of the bugs will be worked out.

Nikolai

NeilL wrote:

Thanks Nik.

Fascinating, and as exciting as reading Agatha Christie

OK, who's Monsieur Poirot?

Candid Arts

NeilL wrote:

Thanks Nik.

Fascinating, and as exciting as reading Agatha Christie

Haha, very interesting. And Agatha Christie is my Favorite author...!

ian408

Scott, adjustments are saved as they relate to specific lenses and the adjustment for a 50mm will not be the same as for a 500mm.

NeilL

Nikolai wrote:

OK, who's Monsieur Poirot?

A-HA! Ca se corse!

Scott_Quier

ian408 wrote:

Scott, adjustments are saved as they relate to specific lenses and the adjustment for a 50mm will not be the same as for a 500mm.

True as long as you are talking about a couple of primes.

My comment was in reference to Nik's 17-55. The "required" adjustment at one end of the focal length range may well differ, and in many cases does differ, from that "required" at the other end (or the middle) of the available focal range of a given lens.

Nikolai

Scott_Quier wrote:

True as long as you are talking about a couple of primes.

My comment was in reference to Nik's 17-55. The "required" adjustment at one end of the focal length range may well differ, and in many cases does differ, from that "required" at the other end (or the middle) of the available focal range of a given lens.

While I do beleive this is true, my particular case was a bit simpler. I checked a bunch of lenses (50mm, 100mm, 17-55, 70-200) and they all showed the same value of -10..-12. So I guess it's just the body, cause 1-2 steps in my case was realy within an error margin. To make it *really* fine you'd need a tripod, b etter lighting/target, an RC, probably tethering for being able to watch the output on a big screen in real time, etc. Definitely doable, but definitely not a 1 minute project.

kdog

Scott_Quier wrote:

My comment was in reference to Nik's 17-55. The "required" adjustment at one end of the focal length range may well differ, and in many cases does differ, from that "required" at the other end (or the middle) of the available focal range of a given lens.

I would really hope that's not the case. An overall shift in the focus plane of the lens is one thing. A non-linearity across the zoom range of the lens sounds like more of a design defect than a quality control issue. Have you actually seen this, Scott? I'd send the lens back to the factory.

-joel

Scott_Quier

kdog wrote:

I would really hope that's not the case. An overall shift in the focus plane of the lens is one thing. A non-linearity across the zoom range of the lens sounds like more of a design defect than a quality control issue. Have you actually seen this, Scott? I'd send the lens back to the factory.

-joel

I've read about it in a number of different forums. And I thought I saw it with one of my lenses - otherwise I wouldn't have mentioned it. I'll have to go back and double check my zooms to see if it manifests in any of them; probably this weekend - I'll post the results of the testing when I have them.

dlplumer

Thanks Nik. I will have to try this

Dan

dlplumer

On another note, I tried the ISO 6400 last night just to see what it would do:



Then with a little Noise Ninja:



I was pretty pleased with the results for 6400.

Date Taken 2008-12-16 19:30:16
Camera Canon EOS 50D
Exposure Time 0.1666s (1/6)
Aperture f/5.6
ISO 6400

Nikolai

dlplumer wrote:

On another note, I tried the ISO 6400 last night just to see what it would do:
I was pretty please with the results for 6400.

Yay!

eoren1

Scott_Quier wrote:

I have found that there are a couple of factos to keep in mind when doing an adjustment:

• If possible/sensible, the AF Microadjustment of a zoom lens should be done at closer to your "normal" shooting distance and the focusing distance does impact the adjustment factor a touch. Your focus distance should be a large multiple (5 - 10) of the minimum focusing distance.
• Even more so, the focal length of the lens can impact on the "correct" adjustment factor.

Hey guys,
So I just got my 50D and played with it a bit last night. I'm very impressed but also concerned that my Sigma 30/1.4 might need a lens microadjustment. This lens was at the factory twice for calibration in the past and seemed fine. I'm not sure right now whether it is the autofocus showing some limitations or the combo of this lens/body.
I was a bit confused about the above. I typically shoot at 2-5 feet distance with the 30mm. So how would you set up the target for this? If it is too far, it seems that the AF area would cover too large of an area of the focus target.
Appreciate the help,
E

divamum

eoren1 wrote:

Hey guys,
So I just got my 50D and played with it a bit last night. I'm very impressed but also concerned that my Sigma 30/1.4 might need a lens microadjustment. This lens was at the factory twice for calibration in the past and seemed fine. I'm not sure right now whether it is the autofocus showing some limitations or the combo of this lens/body.
I was a bit confused about the above. I typically shoot at 2-5 feet distance with the 30mm. So how would you set up the target for this? If it is too far, it seems that the AF area would cover too large of an area of the focus target.
Appreciate the help,
E

Eoren -

Did you see that Scott Quier did an extensive discussion of lens adjustments with the 50d in the Technique forum? It's fairly recent - should be near the top still I'm guessing. HTH!

eoren1

divamum wrote:

Eoren -

Did you see that Scott Quier did an extensive discussion of lens adjustments with the 50d in the Technique forum? It's fairly recent - should be near the top still I'm guessing. HTH!

Thanks for pointing me to the correct forum!
I had searched for scott's posts in the gear section having wrongly remembered seeing the post there and could not find it. Began thinking that I had imagined that whole post
I've got it now. Only problem is it is 8 degrees outside and there is no way i'm shooting tree bark today

Scott_Quier

eoren1 wrote:

Hey guys,
So I just got my 50D and played with it a bit last night. I'm very impressed but also concerned that my Sigma 30/1.4 might need a lens microadjustment. This lens was at the factory twice for calibration in the past and seemed fine. I'm not sure right now whether it is the autofocus showing some limitations or the combo of this lens/body.
I was a bit confused about the above. I typically shoot at 2-5 feet distance with the 30mm. So how would you set up the target for this? If it is too far, it seems that the AF area would cover too large of an area of the focus target.
Appreciate the help,
E

If you typcially shoot at that distance, I'm guessing that's the distance at which you would/should to the AF Microadjustment correction.

divamum wrote:

Eoren -

Did you see that Scott Quier did an extensive discussion of lens adjustments with the 50d in the Technique forum? It's fairly recent - should be near the top still I'm guessing. HTH!

You can find that thread here

eoren1 wrote:

Thanks for pointing me to the correct forum!
I had searched for scott's posts in the gear section having wrongly remembered seeing the post there and could not find it. Began thinking that I had imagined that whole post
I've got it now. Only problem is it is 8 degrees outside and there is no way i'm shooting tree bark today

Wimp! :lol4 Whatever happened to "suffing for your art?" Seriously, I would find a nicely textured, high contrast target that you can orient to such that the surface is not all the same distance from the camera and use that for your target. It just happened that it was nice outside and the light was right and the trees were conviently located in my backyard (I'm sure my neighbors thought I was on drugs, taking a gazillion photos of the same tree with multiple lenses - but who cares what they think!).

eoren1

hey Scott,
Actually your tree shot reminded me of my first days with the Sigma 30. Shot the same tree from various positions and at all apertures which prompted the first visit to the repair center. Then reshot the trees and noticed that they had fixed near focus but not distance thus prompting a return visit. They got a nice CD from me with all of those tree shots! I'm curious to see what happens when I try out your method.
E

Blurmore

Just checked Newegg and they are listing the 50D body only for CHEAPER than the 40D...damn.

I don't really NEED a new camera, and I told myself that my next camera after the 40D with be a 1D series but wow that is tempting. My 30D is still chuggin along, and while I like the 40D I'm not at all impressed with the 50D's high ISO results, pixel pitch is definitely getting to high. I'd love to have this micro adjust, but I'd also like all those extra focus points in the 1D series. Quite a conundrum.

eoren1

Blurmore wrote:

Just checked Newegg and they are listing the 50D body only for CHEAPER than the 40D...damn.

I don't really NEED a new camera, and I told myself that my next camera after the 40D with be a 1D series but wow that is tempting. My 30D is still chuggin along, and while I like the 40D I'm not at all impressed with the 50D's high ISO results, pixel pitch is definitely getting to high. I'd love to have this micro adjust, but I'd also like all those extra focus points in the 1D series. Quite a conundrum.

Amazon will actually save you $50 over that price
Just got mine from there. Have to buy before 1/17 though.

ssimmonsphoto

You have officially made my wait until Tuesday even harder! Yup. I'm getting one! I'm super psyched!

Thanks for the info on your microadjustments. That will give me some fun things to play around with when it's below zero outside.

[Deleted User]

ssimmonsphoto wrote:

You have officially made my wait until Tuesday even harder! Yup. I'm getting one! I'm super psyched!

You should have gone with the Second Day Air delivery! I ordered mine yesterday from B&H along with a 100-400 for wildlife shots. Went with the 28-135 kit lens for $200 extra since I don't have any other lenses. They only wanted $18+ to move from their Free Delivery "It should be there next Tuesday or Wednesday" to 2nd Day "It will be there on Friday." Figured it gave UPS four less days to mess around with it and I would have something to play with over the weekend.

Also noticed the lens went up $114 overnight.

ssimmonsphoto

Jim K wrote:

You should have gone with the Second Day Air delivery! I ordered mine yesterday from B&H along with a 100-400 for wildlife shots. Went with the 28-135 kit lens for $200 extra since I don't have any other lenses. They only wanted $18+ to move from their Free Delivery "It should be there next Tuesday or Wednesday" to 2nd Day "It will be there on Friday." Figured it gave UPS four less days to mess around with it and I would have something to play with over the weekend.

Also noticed the lens went up $114 overnight.

Oh, man, that was so insanely tempting. Heck, I also went out and just bought it for the instant gratification. But the fact that my husband just told me out of the blue to order it was a shock enough. I wasn't going to push my luck too hard! As for the price thing, I've been seeing the prices on everything start to rise. Makes me glad I ordered when I do.

[Deleted User]

It's Finally Here
Well, UPS showed the package "Out for Delivery" at 8:15 AM this morning. 7:00 PM and I am pacing in the road when "Brown" finally shows. Ten hours and 45 minutes to drive the camera three miles

Waiting for the battery to charge...