I think I may have found the root cause of my 7D misfocusing problem!

[spheredome]

Even on my 5DMK2, the AI servo with fixed spot focus at centre can sometimes misbehave. Instead of maintaining around that distance a static object, it began to beeps suddenly and somewhat jump to another distance making the subject out of focus.

I don't take action photos, so each time I will listen for the AI beeps when it is not suppose to.

 

[rueyloon]

I wasn't quite happy with the results, especially when I'm doing high speed continuous with AI servo using all type of AF pt selection.

Are you shooting a stationary subject with SERVO ? the servo mode is made to predict movements and compensate for that the moment you press the shutter. It is always very "jittery" try using spot focus and you'll get better results.

cheers

 

[shahrulesa]

sorry TS, but the banding looks like it's caused by fluorescent lighting. Try shootiing under some tungsten or outdoors. Even my 5D II will get that occasionally when shooting under fluo. Just look at your sequence, it happens at regular interval.

as for the AI servo not spot on, have you played with the custom function, I believe one of the CF makes purposely make the AF do that for sports when you need the photo finish and sorts. Try checking the manual for which mode you 'd need for constant AF.

 

[hobbit6003]

Are you shooting a stationary subject with SERVO ? the servo mode is made to predict movements and compensate for that the moment you press the shutter. It is always very "jittery" try using spot focus and you'll get better results.

cheers

No, the AI servo is used on moving subjects eg. my son playing soccer.

The OOF shot I posted is on auto AF selection, single shot. Somemore, I focused until the focus point I want befor I made the shot.

 

[flipfreak]

No, the AI servo is used on moving subjects eg. my son playing soccer.

The OOF shot I posted is on auto AF selection, single shot. Somemore, I focused until the focus point I want befor I made the shot.

i just went to take a look at how u ran the test. if u use auto af point selection, there will be a tendency for the spot to be OOF if the camera locks onto multiple points like what u did.

that is normal. the various points are all on different focal planes. some points will be sharper than others. there is no way all the points will be sharp.

a difference of a few cm is enough to throw a point OOF.

your test is not scientific and sound. i suggest u learn more abt how AF works before running such tests to scare yourself.

right now, i can conclude your camera is working perfectly fine.

 

[oeyvind]

http://en.wikipedia.org/wiki/Fluorescent_lamp#Flicker_problems <- dude, u need to read this

 

[hobbit6003]

i just went to take a look at how u ran the test. if u use auto af point selection, there will be a tendency for the spot to be OOF if the camera locks onto multiple points like what u did.

that is normal. the various points are all on different focal planes. some points will be sharper than others. there is no way all the points will be sharp.

a difference of a few cm is enough to throw a point OOF.

your test is not scientific and sound. i suggest u learn more abt how AF works before running such tests to scare yourself.

right now, i can conclude your camera is working perfectly fine.

Hi flip,

Thanks for the advise.

The senior tech has concluded otherwise, and attributed it to some sensor problem which wasn't like anything he saw on the 7D before, as he noticed something we hadn't seen as we focused on the misfocusing issue: the grain of pics looked very funny to him and he hadn't seen this kinda grain before, he remarked that some of my 100% cropped pic looked like smudgy poster colour painting to him.

He told me to get ready to have the unit replaced, and have sought permission to send my pics to HQ for analysis, as they dunno what to make of it....

See this 100% cropped of the cheetah: ISO 1600, 1/1600 sec, f5.6, EV -1/3

THe original pic:

These are all unadulterated RAW files.

In other pictures, it noted that although everything is on the same focusing plane, the shirt of my son is tack sharp, but the little facial detail is totally lost and looked smudgy, as if there's noise ninja applied to the face but no the rest of the pics.

Flash pics looked fine for full facial portrait, although he also noted the lost of facial detail in pics which is taken at a further distance, and to him, it doesn't look normal.

I told him I'm fine with being a guinea pig and try to see if software tweaking will rectify the problem, and at worst, I'll go for a replacement unit.

 

[hobbit6003]

He also picked out this pic of the Douc Langur: ISO 3200, 1/2000 secs, f5.6

He also remarked that the sensor seemed to have a filter in front of it, that gives such 'artistic' effect.

 

[vlg134]

He also picked out this pic of the Douc Langur: ISO 3200, 1/2000 secs, f5.6

He also remarked that the sensor seemed to have a filter in front of it, that gives such 'artistic' effect.

how come have the black dot like smudge on the photos. haha... what lens you use?

 

[hobbit6003]

how come have the black dot like smudge on the photos. haha... what lens you use?

That's what the senior technician was very interested to find out...it is not normal even at high ISO like this, he said.

This is the EF 400mm f5.6L.

 

[Sailor73]

Hi,

Sorry but I am really not following here.... your Cheetah's pics @ 100% crop seems ok to my untrained eyes but you mentioned that the technician concluded that the sensor is grainy and smudgy and could be faulty. I relook at some of my pics at 100% crop and all along, I thought that with higher pixel count, the smudgy outcome is "normal" (or I was misled all the while and it should be sharp instead?!!)

I am attaching some pics on both uncropped and 100% expansion. The pics looks smudgy to me when expanded (and all of my pics are smudgy at 100% and 200%)..... so I am seriously not sure if my 7D is normal or like the technician said... "Looks smudgy".

This is unexpanded taken at 1/100, f4 @ ISO200......

This is 100% view.......

Another unexpanded view @ 1/160, f4 @ISO200.....

Another 100% view.....

What do you guys think of the quality ? Is it normal to be this smudgy or it should be sharper ?

Hi flip,

Thanks for the advise.

The senior tech has concluded otherwise, and attributed it to some sensor problem which wasn't like anything he saw on the 7D before, as he noticed something we hadn't seen as we focused on the misfocusing issue: the grain of pics looked very funny to him and he hadn't seen this kinda grain before, he remarked that some of my 100% cropped pic looked like smudgy poster colour painting to him.

He told me to get ready to have the unit replaced, and have sought permission to send my pics to HQ for analysis, as they dunno what to make of it....

See this 100% cropped of the cheetah: ISO 1600, 1/1600 sec, f5.6, EV -1/3


THe original pic:


These are all unadulterated RAW files.

In other pictures, it noted that although everything is on the same focusing plane, the shirt of my son is tack sharp, but the little facial detail is totally lost and looked smudgy, as if there's noise ninja applied to the face but no the rest of the pics.

Flash pics looked fine for full facial portrait, although he also noted the lost of facial detail in pics which is taken at a further distance, and to him, it doesn't look normal.

I told him I'm fine with being a guinea pig and try to see if software tweaking will rectify the problem, and at worst, I'll go for a replacement unit.

 

[raydio]

Yes I agree that your photos looks a little smudgy but this to me looks like camera shake (particularly photo # 1). The floral shot may have been affected by a breeze and/or camera shake. I think that your camera is fine. However, you did not mention the lens and the focal length used.

To be absolutely sure you can conduct a simple test. Put your camera on a sturdy tripod; use mirror lock up and a cable release and take a photo of the contrasty object in good light (preferably outdoors). Under these conditions, your photo should be as sharp as a tack. If not, send it to Canon for review. Any other thoughts, anyone?

Good luck.

Hi,

Sorry but I am really not following here.... your Cheetah's pics @ 100% crop seems ok to my untrained eyes but you mentioned that the technician concluded that the sensor is grainy and smudgy and could be faulty. I relook at some of my pics at 100% crop and all along, I thought that with higher pixel count, the smudgy outcome is "normal" (or I was misled all the while and it should be sharp instead?!!)

I am attaching some pics on both uncropped and 100% expansion. The pics looks smudgy to me when expanded (and all of my pics are smudgy at 100% and 200%)..... so I am seriously not sure if my 7D is normal or like the technician said... "Looks smudgy".

This is unexpanded taken at 1/100, f4 @ ISO200......

This is 100% view.......

Another unexpanded view @ 1/160, f4 @ISO200.....

Another 100% view.....

What do you guys think of the quality ? Is it normal to be this smudgy or it should be sharper ?

 

[flipfreak]

Hi flip,

Thanks for the advise.

The senior tech has concluded otherwise, and attributed it to some sensor problem which wasn't like anything he saw on the 7D before, as he noticed something we hadn't seen as we focused on the misfocusing issue: the grain of pics looked very funny to him and he hadn't seen this kinda grain before, he remarked that some of my 100% cropped pic looked like smudgy poster colour painting to him.

He told me to get ready to have the unit replaced, and have sought permission to send my pics to HQ for analysis, as they dunno what to make of it....

See this 100% cropped of the cheetah: ISO 1600, 1/1600 sec, f5.6, EV -1/3

THe original pic:

These are all unadulterated RAW files.

In other pictures, it noted that although everything is on the same focusing plane, the shirt of my son is tack sharp, but the little facial detail is totally lost and looked smudgy, as if there's noise ninja applied to the face but no the rest of the pics.

Flash pics looked fine for full facial portrait, although he also noted the lost of facial detail in pics which is taken at a further distance, and to him, it doesn't look normal.

I told him I'm fine with being a guinea pig and try to see if software tweaking will rectify the problem, and at worst, I'll go for a replacement unit.

so from an AF problem it has become a sensor issue?

i maybe wrong but i think he has overrated the 7D sensor to think it can give clean images at iso 3200.

anyway hope u get your camera fixed and back to shooting soon. :lovegrin:

 

[doodah]

In other pictures, it noted that although everything is on the same focusing plane, the shirt of my son is tack sharp, but the little facial detail is totally lost and looked smudgy, as if there's noise ninja applied to the face but no the rest of the pics.

Flash pics looked fine for full facial portrait, although he also noted the lost of facial detail in pics which is taken at a further distance, and to him, it doesn't look normal.

I told him I'm fine with being a guinea pig and try to see if software tweaking will rectify the problem, and at worst, I'll go for a replacement unit.

I don't think there's anything wrong with your sensor.

But if the replacement unit works, so be it.

The only sensible way is to take one shot in AF mode and immediately after grab another shot with manual focus under 10x magnification in live view. If the latter makes a dramatic improvement to your shot, the answer clearly lies in the AF unit and not the sensor.

A replacement unit is fine as long as they can get it to work. I tested a replacement unit and its AF is just as inconsistent.

 

[David]

Sailor 73,

Cool... How did you add the focusing squares to your images? Are they screen shots from Canon's software?

Ok back to your question. You didn't choose the best pictures to study the image quality. And there is missing info. Both the images you have taken contain possible movements so it's biased to judge sharpness like that.

Bear in mind there are many factors that can affect the image quality: Type of lens used, ISO (yours look pretty fine), shutter (too slow?) and aperture (too wide?) shot at, any hand shake, etc.

I also think we digital photographers sometimes get all too paranoid with peeping up close and wanting everything sharp. Not sure if you have shot films before. But I can assure you back in those days, even if you used very good L lenses and focus was on the dot, images might not always look tack sharp at large prints. The 35mm film just didn't give that razor sharp images at high magnification. We are already a lot better today.

But no one really cared then. If any photographer was anal about maintaining sharp pics at large enlargements (the way we always pixel peep in today's digital lingo), then medium or large format was the way to go.

That said, I'm not sure if I appreciate Hobbit6003's issue. Shooting at high ISO and getting that kind of results, what's wrong? In fact, if anything, just by judging on those images, I'm impressed by the 7D's high ISO quality. Try shooting with an old Canon D30 at ISO1600 or use a ISO1600 film!

I'm also absolutely amused that the Canon technician was even surprised about the "Douc Langur" pic having an artistic effect. Hello? We are talking about ISO3200 are we not?

Guys, shoot more and appreciate photography rather than give yourself unfounded worries doing tedious, laboratory work with your expensive cams/lenses! Definitely, there are times to be paranoid with image quality but sometimes, things are taken way too far. This is one instance.

 

[Sailor73]

The focusing boxes are part of DPP software and I use it to analyze my pics.

And you guys are right, I could have contributed to "smudginess" of my pics due to my handshake, the subject's movement cum environmental factor...... I guess it doesn't help especially after when I compared my 500D's pics at 100% (very sharp) vs. the 7D's @ 100% (softness)..... but they are both different monsters to begin with :embrass:

BTW, The 1st pics' focal length is 82mm, taken at 1/100, f4 @ ISO200 while the 2nd pics is 97mm, taken @ 1/160, f4 @ISO200.... all using 24-105mm.

Will try something else tomorrow..... geez, I wanna ensure that my cam can take as sharp as those which can shows a person's pores on his face.... Wauhahahahaha !:bsmilie:

 

[doodah]

Guys, shoot more and appreciate photography rather than give yourself unfounded worries doing tedious, laboratory work with your expensive cams/lenses! Definitely, there are times to be paranoid with image quality but sometimes, things are taken way too far. This is one instance.

There is some truth in this.

BUT, if the camera AF fails and you have to start throwing shots away BECAUSE of the awful AF, you'll know what the pain is like.

Consider the following macro shot where the depth of field is very thin. In Singapore, it's not always practical to manual focus macro shots 'cos the bugs are too nervous.

I will be mighty pi**ed if I have to throw away good shots only because of lousy AF. And it's happened to me before even though I clearly know what I'm doing.

I had another shot similar to the one below with a different worker. But because of lousy off-center AF sensors on the 400D, I had to discard the other shot even though the colors were better and the worker had a more friendly smile. :cry:

I bought the 7D thinking the off-center AF sensors will perform more reliably since they are all crossed. Now, if it puts up inconsistent AF performance, I may as well discard the camera and stick to the digital Rebel with its center AF sensor only. :angry:

 

[boracayangels]

Sailor 73 I really do believe you have a case of back focusing.

Look at the character behind the fellow you were focusing, he seems sharp.

The flowers too, bf.

David, I do agree with your philo of shooting more and appreciate photography and I believe this is what it is all about. Wanting to push ourselves to the next level only to find that the support are not there...............da

Spending hours walking and looking only to miss the opportunity to shoot coz the sensor or Af is too jumpy...................ahhhhhhhhhhhhhhhh.

Oh i intentionally leave out mentioning he or she coz there ain't many female working behind those workbenches, get my drift, senior tech, managers or what. Focus on the eyebrows.............

 

[zenhora]

Hobbit, is this your first camera? you were shooting at 1600 and 3200... what were u expecting? seem perfectly fine to me!

If thats something wrong with my sensor..you should see my 400D 1600 iso...

By the way i own a 7D too

 

[hobbit6003]

Hobbit, is this your first camera? you were shooting at 1600 and 3200... what were u expecting? seem perfectly fine to me!

If thats something wrong with my sensor..you should see my 400D 1600 iso...

By the way i own a 7D too

This is my 4th digital SLR, and I had the 350D, 30D as well. Now, I also have the 50D and D300 at my disposal.

Guys, it is not the noise that we're having concern, and of course at a high ISO like these, noise is common.

The point of contention is not the amount of noise, but rather the quality of noise, that is causing concern to both the tech and I.