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Occasional Contributor
Posts: 7
Registered: ‎04-09-2018

Re: Bad Coma? Or Focus issue?

These were taken on a t3i. But the same results come from a 7D, a 5DMIII, a 5DMII, a 6D, and a T1i. 

I'm at 200mm in both photos. The nest is a crop from the original to show what I'm talking about. I wish I had a different copy for comparison, but I don't currently. However, on a tripod, using manual focus, there is no sharpness achievable. Literally none. That nest was only ~5 yards from me. Over the last decade, I have used and/ or rented this particular lens model about twice a year. I've never once had a problem with it, regardless of camera body. 
Which is why this is baffling. This is the full image. I was about 5 yards away. I have shot many portraits at this distance with this lens. Always tack sharp. 
IMG_1340.jpg

Occasional Contributor
Posts: 7
Registered: ‎04-09-2018

Re: Bad Coma? Or Focus issue?

You'd think that, but I've probably used about 20 different copies of this lens since 2011. If I'm suddenly doing something wrong, that would be a surprise.
This lens can and does fall out of calibration. And that's what I'm trying to find out. Best or not (my opinion is that it is the best), **bleep** happens. And that these are both used copies who's origins are unknown outside of seller description. The first used copy that did it had some flaws it the lens that weren't noted by the seller. Such as a tear in the rubber seal on the mount. But this one is perfect, physically. 
The only idea I really have is that the screw used to calibrate the lens is somehow loose. Which seems crazy

VIP
Posts: 8,886
Registered: ‎12-07-2012

Re: Bad Coma? Or Focus issue?

It appears as if you have answered your question yourself.  I'm satisfied so, I would send the lens to Canon for a C&C.  It will come back in perfect condition.

A lot less stuff for 2018 but still a lot of Canon stuff. Along with, a lot of other stuff.
Occasional Contributor
Posts: 7
Registered: ‎04-09-2018

Re: Bad Coma? Or Focus issue?

Yeah, that's where I'm a bit stumped. I don't own nearly as many lenses, but I have probably rented/ borrowed about 20 different copies of this lens since 2011. I've never experienced this issue. Only one copy with a bad auto-focus mechanism. But I usually photograph using manual focus anyway, so that wasn't an issue for me. 

I was disturbed to find this issue on the first copy of the lens I purchased (used), but as I was saying elswhere, the lens had damage that was not noted in the description. So I sent it back in and got this copy of the lens. It seemed to work perfect at first. I did two photo shoots with it and on the second one, I noticed some of the shots looked like the previously noted shots. Since I do use auto focus when doing portraits, I chalked it up to just missed focus. 
However, when I finally got to go out into the woods and photograph, every shot out past about 125-135 exhibited that odd blur as seen in the nest photo. I shot that with Manual focus on a very heavy 90's Gitzo tripod The nest is literally the sharpest I could achieve from 6 yards away at 200mm. Well within the focal range. This was also at 1/640th of a second shutter speed. IS off and on gave the same results, both on setting 1 and 2. 

Thinking it might be my camera, like with the first used copy I purchased, I sought out all of my friends who also use Canon cameras. Same results on a 7D, a 5DMIII, a 5DMII, a 6D and a t1i. 

As far as photography and technology are concerned, I tend to fall into the catagory of people who spends a lot of time researching how the lenses themselves work. Watching videos on lens construction with aspirations on being able to repair them myself. I've done so for several Sigma lenses and have repaired/ replaced various internal components on at least a dozen camera bodies from a t2i to soldering a new USB port onto a 5DMIII. 

This isn't my first rodeo, but it is the strangest. However, I've never had this issue with this particular line of lenses. I just assumed they were all nearly perfect with very small batch variation as goes most lenses. Looking at videos of out of calibration lenses, these issues are in line with that, but what bothers me is that every photo from the first shoot I did was sharp. Or at least, they seemed to be. I might have kept most photos well under 200mm. I don't normally pay attention to my focal length when shooting unless there's an issue. 

Side note: I just found out my mother has lung cancer (not surprising, as she smokes like a chimney, but still...) and my friend has been going through some pretty bad stuff as well. So we went for a nice drive around the countryside. Obviously this means stopping to photograph something every ten feet. I was using the 70-200 beause it photographed fine at wider angles... Or so I thought. Looking closely at the photos I took the same "blur" is present, but less noticeable due to the wider field of view/ less magnification.

Anyway, thank you for your response. It was the most reasonable and less patronizing than most.

I viewed countless numbers of posts about people having similar issues with this particular lens and, on this forum n particular, the poster was usually new to photography and the comments section would univerally patronize the OP and tell them they're just using the lens wrong or that it was obviously branches or some other obstruction in the foreground. When looking at the images, it was definitely not the case.

As somebody else replied to me claiming it was just objects in the forground. No, definitely not objects in the forground. Shooting at the photo studio/ gallery/ print shop/ customing framing shop where I've worked for the last 5 years, there was nothing in the foreground that would have caused this there. And the couple of branches in front of the nest are apparent. The blur is visible across the frame. If I had to guess, the calibration is off and/ or the calibration screws are somehow loose. 
My other guess is that it could involve the IS system not quite working properly and shifting a little bit while exposing the image. I guess that due to a similar looking effect as shown to happen with a particular Sigma lens as noted by another photographer from an article on Petapixel. 

Anyway, I apologize for what is likely a very lengthy response. My plan is to just send it in. I was really hoping it was just user error/ something noted on a particular camera body or perhaps just an update needed by the lens. IE: Issues that could be solved for little to no money. 


Occasional Contributor
Posts: 7
Registered: ‎04-09-2018

Re: Bad Coma? Or Focus issue?

Yeah, basically. I was just hoping for an easier solution. Or at least confirmation that I wasn't insane. :/

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VIP
Posts: 8,886
Registered: ‎12-07-2012

Re: Bad Coma? Or Focus issue?

"Or at least confirmation that I wasn't insane."

 

I am not sure this qualifies you as not being insane but it will get you  perfect working lens.  Good luck.  Smiley Happy

A lot less stuff for 2018 but still a lot of Canon stuff. Along with, a lot of other stuff.
Respected Contributor
Posts: 1,892
Registered: ‎02-26-2015

Re: Bad Coma? Or Focus issue?


@Chip_Ormwrote:

There are no out of focus branches in the forground. I'm about 6 yards away. 


OOF Branch.jpg

 

 

Honored Contributor
Posts: 6,111
Registered: ‎08-13-2015

Re: Bad Coma? Or Focus issue?


@Chip_Ormwrote:

These were taken on a t3i. But the same results come from a 7D, a 5DMIII, a 5DMII, a 6D, and a T1i. 

I'm at 200mm in both photos. The nest is a crop from the original to show what I'm talking about. I wish I had a different copy for comparison, but I don't currently. However, on a tripod, using manual focus, there is no sharpness achievable. Literally none. That nest was only ~5 yards from me. Over the last decade, I have used and/ or rented this particular lens model about twice a year. I've never once had a problem with it, regardless of camera body. 
Which is why this is baffling. This is the full image. I was about 5 yards away. I have shot many portraits at this distance with this lens. Always tack sharp. 
IMG_1340.jpg


This is one of the more difficult focusing scenarios.  Trying focus on a subject that is within a cluster of branches.  It will test your gear, and your skill equally.  I typically use One Shot focusing mode, with BBF enabled, for these types of shots.  Using AI Servo does not give photos as sharp as One Shot, even with a high shutter speed >1/1000.  

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"I don't rent software. I use Photoshop CS6, ACR 9.8 and Lightroom 6.8 ."
Honored Contributor
Posts: 6,111
Registered: ‎08-13-2015

Re: Bad Coma? Or Focus issue?

I copied this from my Facebook page, so I do not have exposure settings.  6D, EF 70-200mm f/2.8L IS II USM, heavy crop.

 

AA7C025F-8B51-4AB3-875B-53037793D05C.jpeg

 

I am sure I cropped this photo, but not how much.  But, I do recall that I used One Shot with BBF.  Once I focused, I could shoot away without worrying about the camera refocusing.

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"I don't rent software. I use Photoshop CS6, ACR 9.8 and Lightroom 6.8 ."
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