# Can't get really sharp images on EOS 40D



## MDesigner (Jun 11, 2008)

I have the highly touted Tamron SP 17-50mm f/2.8 lens with an EOS 40D.  I was taking some shots and when I zoom in 1:1 at the part of the photo where the camera was focused, I expect it to be pretty sharp.. but it's a bit fuzzy to be honest.  I tried different f-stops.. 2.8, 8, 10, tried ISO 200, ISO 400.  What else would contribute to this?  Am I just expecting too much, maybe?  I'll see if I can post photos later.


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## BoblyBill (Jun 11, 2008)

I don't think it's the camera that would give you soft images but possibly the lens. I would like to see some of these pics if you could please. what shudder speed you shooting at?


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## icassell (Jun 11, 2008)

I have the Tamron 17-50mm with my 30D and haven't had soft issues once I learned about AI and AI servo.  I had been a manual-focus 35mm person for years, so the whole AF thing was new to me.  I still don't trust it entirely and frequently will manual focus (have been thinking of buying a Katzeye split-screen viewing screen).  I don't think you're having a camera problem -- I think you're getting into situations where the AF just isn't doing it for you.

Another thought -- what shutter speed are you using? Are you sure it isn't camera shake?

I love the lens -- it has become my standard walkabout glass.


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## MDesigner (Jun 11, 2008)

Any shutter speed mostly.  1/60, 1/800.  I'll see if I can take some more shots later and post 1:1 cropped sections to illustrate this.


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## sultan (Jun 11, 2008)

How fuzzy? If a sharp edge is about 5 or less pixels wide, that's normal. Just turn up the sharpening and the 5 pixel edge becomes a 2 pixel edge.

If it's a great blur, check the focus and if that's not the problem, you have a defective lens. Return it.

The shutter speed sounds fine, it's not camera shake.


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## julie32 (Jun 11, 2008)

Are you using a tripod?? Can you post some of your images?


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## Mav (Jun 11, 2008)

Yeah post some photo samples.  A good number of these third party lenses appear to have front or back-focusing issues, which could cause softness issues as well so keep that in mind.


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## RyanLilly (Jun 11, 2008)

But also, a picture will not really look "sharp" at 100% on a computer screen.


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## MDesigner (Jun 11, 2008)

Well, I was zooming in to 1:1 on my 40D's LCD display, which I was just told is not a good idea.   On the computer, it looks better at 1:1 for sure.  But then again, I was looking at night shots (shot on a tripod, ISO 800), so that's not a great test either.

I think I'm obsessing.  I expected 1:1 to be razor sharp, that's all.  Not on this Tamron.. but maybe on my future lens.. Canon 50mm f/1.4!


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## passerby (Jun 11, 2008)

RyanLilly said:


> But also, a picture will not really look "sharp" at 100% on a computer screen.


 
Good idea if you have go to the store you purchased from and try it with different cameras. Hopefully you have a reciept for that lens and still under warranty.


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## Mav (Jun 11, 2008)

MDesigner said:


> Well, I was zooming in to 1:1 on my 40D's LCD display, which I was just told is not a good idea.   On the computer, it looks better at 1:1 for sure.  But then again, I was looking at night shots (shot on a tripod, ISO 800), so that's not a great test either.
> 
> I think I'm obsessing.  I expected 1:1 to be razor sharp, that's all.  Not on this Tamron.. but maybe on my future lens.. Canon 50mm f/1.4!


Err, okay, well I think you just answered your own question.  ISO 800 shots aren't going to  look sharp at 100% because they'll have either more noise, or more noise reduction, both of which muddy up images.  And there's no reason to be at ISO 800 on a tripod at night either.  What you want to do is shoot a long exposure at base ISO and use the camera's self timer or a remote release to minimize any vibration in your setup.  So I doubt there's anything wrong with your camera or lens.  You'd need to post a sample along with the EXIF data (shot data, shutter speed, aperture, iso, etc) for anybody here to know for sure.  You may be obsessing, but it's probably technique related too.


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## BoblyBill (Jun 11, 2008)

I have a 40D as well and one of my complaints is that the LCD DOES NOT do a good job of seeing sharpness... I have learned what to look for on the LCD that will give me a sharp shot at 100% and then I'm satisfied after that.

Here's an example of what I'm talking about:

Here's the file.







Here's what the 40D would give you on the LCD if you zoomed in all the way on the eyes (approx.)






Here's what the image file actually is at 100% (minus a little sharpness due to upload to flickr). 






note: I shot this with a 17-40m L, but it does give you an idea of what to look for in the "sharpness" of the LCD.


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## MDesigner (Jun 12, 2008)

17mm, ISO 800, 0.8/sec @ f/2.8

Image showing which points i'll be showing 1:1 crops of:


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## MDesigner (Jun 12, 2008)

Mav said:


> And there's no reason to be at ISO 800 on a tripod at night either.  What you want to do is shoot a long exposure at base ISO and use the camera's self timer or a remote release to minimize any vibration in your setup.



What exactly is base ISO?  100?  200?


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## Senor Hound (Jun 12, 2008)

MDesigner said:


> What exactly is base ISO?  100?  200?



As low as possible.  Since shutter speed isn't a big factor in shooting tripod shots, you wanna go with the least amount of noise possible.

I see the problem you have to be with the back LCD, right?  Its not that the camera itself isn't taking good photos, its just they look blurry on the back when you try to look at them?


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## dylj (Jun 12, 2008)

MDesigner said:


> 17mm, ISO 800, 0.8/sec @ f/2.8
> 
> Image showing which points i'll be showing 1:1 crops of:


 
Try these with ISO 100. They look plenty sharp for me, though.


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## Sw1tchFX (Jun 12, 2008)

Could be a few things, field curvature, depth of field, front or back focusing, camera shake..

they look ok to me for a shot at f/2.8.


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## Garbz (Jun 12, 2008)

I'm sorry but did you just really compare L glass to a cheap Tamron? Also when was the last time you printed an photo that big? If it's a bit blurry apply an unsharp mask.


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## Mav (Jun 12, 2008)

MDesigner said:


> 17mm, ISO 800, 0.8/sec @ f/2.8
> 
> Image showing which points i'll be showing 1:1 crops of:
> http://img149.imageshack.us/img149/8660/zoompointsqn3.jpg
> ...


These look fine to me.  

They don't look completely sharp because ISO 800 isn't completely sharp, and because only one of those points is really in focus.  The lens only focuses at one point so either one of those points or the other is in an area that's falling out of focus.

Drop your ISO down to 100, and stop the lens down to at least f/4 and you should get much better results.  It'll also give you an exposure time of about 12-13 seconds.  This is how most night photography like this is done.  And then make sure you're using either a remote shutter release, or the time delay feature on the 40D so that any vibration from hitting the shutter itself dampens out before it starts taking the photo.  Otherwise you'll get blurry photos from the camera setup vibrating.


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## BoblyBill (Jun 12, 2008)

Garbz said:


> I'm sorry but did you just really compare L glass to a cheap Tamron? Also when was the last time you printed an photo that big? If it's a bit blurry apply an unsharp mask.


 

I wasn't comparing the two. I was giving an example of how blurry the LCD is on the back of the camera. That was one of the shots that I still had on my camera last night so I used it so that I could blur the sharp crop to look similar to what the LCD looked like. I don't really want to print a picture that big... yet... but sadly I'm a pixel pusher and I like to have see pictures sharp even at 100%.


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## BoblyBill (Jun 12, 2008)

To the OP... Mav is completely right. throw that down to 100 ISO with an aperature of f/4, and I bet you'll get better performance of that lens.


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## MDesigner (Jun 12, 2008)

BoblyBill said:


> To the OP... Mav is completely right. throw that down to 100 ISO with an aperature of f/4, and I bet you'll get better performance of that lens.



Very curious why the adjustment to f/4 instead of f/2.8.


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## Mav (Jun 12, 2008)

MDesigner said:


> Very curious why the adjustment to f/4 instead of f/2.8.


Because lenses usually don't perform their best at their maximum aperture.  If you stop down 1 or 2 stops to f/4 or f/5.6 you're likely to get sharper results.  This is true of most lenses, although different lenses tend to have very different starting points as to how sharp they are wide open.


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## MDesigner (Jun 12, 2008)

Great, thanks for all the tips..very helpful!


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## Dao (Jun 12, 2008)

MDesigner said:


> Very curious why the adjustment to f/4 instead of f/2.8.




FYI, according to photozone:

At 17mm, your lens perform the best at F4
From 24mm to 50mm, it perform the best at F5.6

But F4 or even f2.8 should still pretty sharp.  I would agree with others try it with iso100 with longer exposure.    And for the type of photo you take, a smaller aperture may look sharper (more DOF).  Please correct me if I am wrong.


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## MDesigner (Jun 12, 2008)

Mav said:


> Because lenses usually don't perform their best at their maximum aperture.



Does that rule apply to prime lenses?


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## reg (Jun 12, 2008)

Is a prime lens a lens?

BTW quit staring at 1:1 crops. You'll drive yourself crazy.


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## Dao (Jun 12, 2008)

I do not think that is a rule.  However, when I look at lenses review sites, it appear that way.  Lens usually performs better few stops down from the max aperture size.


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## MDesigner (Jun 12, 2008)

reg said:


> Is a prime lens a lens?



Hey, just asking.  May I remind you the forum we're in:

"*The Beginners Place* Brand new to photography, or brushing up on some of the basics?"

I know that prime lenses tend to be sharper than zoom lenses.  Just wondering if a prime lens at its max aperture will yield better (sharper) results than a zoom lens at its max aperture.


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## Mav (Jun 12, 2008)

MDesigner said:


> Does that rule apply to prime lenses?


Yes, although generally speaking prime lenses are going to be sharper than consumer grade zooms, so they may be as sharp as you'd ever need them to be even wide-open at their maximum apertures.  My Nikon 50mm f/1.8 lens was crazy sharp even wide open at f/1.8, and got ridiculously sharp stopped down to f/2.8 or f/4.  It depends on the lens though.  Pro level zooms that cost $1000+ are usually going to be as sharp as you need them to be at maximum aperture and can shoot them there all day if you want.  This is also why it's impossible to shop for lenses just based on specs alone.


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## icassell (Jun 12, 2008)

Garbz,

I think one can compare the Tamron 17-50 to an L lens. I did compare them side-side when I bought it. I had the option of buying either and I love that Tamron (which is not particularly cheap, just less expensive than Canon).  The build is good and the optics are excellent ... I just miss USM (which hasn't been a real issue for me).


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## MDesigner (Jun 12, 2008)

I can be objective if I want to.  I'll do so now.

reg had some good advice when he said "BTW quit staring at 1:1 crops. You'll drive yourself crazy."  The other comment, "Is a prime lens a lens?" was a snotty way of saying "yes, the rules applies to prime lenses."  Maybe reg is a photo god and finds my questions silly.  If that's the case, maybe he should keep in mind this is a beginner's forum, and maybe he's better off spending his precious time with pros than trying (key word there) to help photo newbs.  If he continues to hang around the beginners' forum and make snotty comments, I'd start to wonder if maybe he just gets off on talking down to people he regards as not as skilled as he.  I'm a photo newb, but I'm a pro in another trade, and I NEVER talk to newbs like that, ever.  Why?  Because I'm not a jackass.

There.  Oh I guess that last part there was a little subjective.. sorry. :roll:


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## elemental (Jun 12, 2008)

Might I be the only one who's thinking that at most one (and possibly neither) of the crops are areas that are in focus, seeing as how they appear to be different distances from the camera? Maybe I'm missing something or pointing out the obvious, but I would imagine a lens wouldn't be very sharp away from its focal point (particularly at f/2.8).


It would be great if this thread actually survived on topic instead of turning into another Beginner*s' *Place bickerfests (yes, that apostrophe drives me crazy).


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## Chris of Arabia (Jun 12, 2008)

elemental said:


> Might I be the only one who's thinking that at most one (and possibly neither) of the crops are areas that are in focus, seeing as how they appear to be different distances from the camera? Maybe I'm missing something or pointing out the obvious, but I would imagine a lens wouldn't be very sharp away from its focal point (particularly at f/2.8).



That looks to be a fair point, though given the size of the image as presented, I'm struggling to work out where the point of focus actually is in this shot - my guess is that it's nearer the camera than either of the two 100% crops.


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## Mav (Jun 12, 2008)

elemental said:


> Might I be the only one who's thinking that at most one (and possibly neither) of the crops are areas that are in focus, seeing as how they appear to be different distances from the camera? Maybe I'm missing something or pointing out the obvious, but I would imagine a lens wouldn't be very sharp away from its focal point (particularly at f/2.8).


Yeah that's what I pointed out above.  Technically only one of those crop areas would be in perfect focus, assuming the camera actually focused on one of them.  At 17mm and f/2.8 the depth of field should be quite large which is why they looked about the same.  Still, at ISO 800 you're looking more at the camera's high ISO capability than anything else.  It'd be easier to see at ISO 100.


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## terri (Jun 12, 2008)

Stay on track and play nice, all.     There is good information here.

Thanks.


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## MDesigner (Jun 12, 2008)

Point of focus was infinity, I believe.  I was focusing about where the truck is.

And BoblyBill: Thanks for the welcome.   I'll definitely be posting photos as soon as I come up with some decent ones I feel are worthy of sharing.

Actually, I do have something I shot years ago, with a Nikon Coolpix 8700, and stupidly lost the original unprocessed JPEG.  Quite sad about it.. as now the shot only exists in 640x480.


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## MDesigner (Jun 12, 2008)

OK, so I got home and set up my tripod, and forced ISO to 100, zoomed to 50mm, put the 40D in Av, and tried two different shots using the 2-sec timer.  Focal point was the barcode. (these crops are 1:1)

First one is f/4.






Second one is f/5.6.






Wow, what a difference.  Dao's advice on f/4 at 17mm and f/5.6+ at 24-50mm was spot on.

This brings up some questions.  Does this mean at 50mm, f/4 will never yield sharp results on this particular lens?  I imagine f/2.8 would've been even worse.. and even at 17mm, f/2.8 might've looked crummy.  So why would we want to sink the cash into a fast lens (I realize f/2.8 isn't amazingly fast) if the widest aperture yields blurry results??


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## BoblyBill (Jun 12, 2008)

Hmm... I have a hard time believing that there would that much difference between f/4 and f/5.6 actually. Were you shooting on manual focus or auto? I would think that the f/4 shot didn't get the focus right.


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## BoblyBill (Jun 12, 2008)

By the way... I like the diamond picture... that's cool.


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## MDesigner (Jun 12, 2008)

You're right.  Here I was trusting the Tamron's AF too much.. bleh.

Auto-focus:






Manual focus (using the very kickass Live View feature):






That's not cool.  So it seems maybe the Tamron's AF is a bit off at f/2.8?


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## Mav (Jun 12, 2008)

The focus may very well be off, but if it's off it'll be off regardless of aperture.  You'll notice it more at larger apertures like f/2.8 because your depth of field is smaller there (less in focus) so mis-focusing is easier to see.


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## MDesigner (Jun 12, 2008)

Ahh, that makes sense.

I think this is the focusing problem many people have claimed this lens has.  Some people have returned the lens and gotten the exact same model in exchange and that one winds up working better.  It might just be an issue of the lens needing to be calibrated (someone else's words, not mine).

I'll have to do some more AF vs MF tests and see if it's consistently off.  I've never noticed it till now.  I'm glad I did these 1:1 comparisons, otherwise I would've never noticed this issue.


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## Mav (Jun 12, 2008)

I'd try a test chart like this to confirm it: http://focustestchart.com/chart.html


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## Dao (Jun 12, 2008)

MDesigner said:


> Ahh, that makes sense.
> 
> I think this is the focusing problem many people have claimed this lens has.  Some people have returned the lens and gotten the exact same model in exchange and that one winds up working better.  It might just be an issue of the lens needing to be calibrated (someone else's words, not mine).
> 
> I'll have to do some more AF vs MF tests and see if it's consistently off.  I've never noticed it till now.  I'm glad I did these 1:1 comparisons, otherwise I would've never noticed this issue.





Just wondering, is your lens assembled in China or made in Japan?


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## MDesigner (Jun 12, 2008)

Dao said:


> Just wondering, is your lens assembled in China or made in Japan?



Made in Japan..says that on the box and the lens


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