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41jas
24-12-2011, 4:50pm
I did a test on my 24-105.. canon lens the other day and again today. I thought I'd post a couple of photos to show you at f4...ITS SHOCKING!!! are they all like this?
I tried the 50mm and its sharp right through.
f4 was at 1/180s
f8 was at 1/45s
So pretty much to get the nice bokeh I want with portraits I can't use the wide open aperture. A bit annoying. The further away the subject it the worse it is. This was taken within the meter.
These are 100% cropped so you can see.
So looks like f4 isn't worth using on my 24-105mm :(
These were focused right on the eye and I tried it a few times with the same results.

41jas
24-12-2011, 5:08pm
these two pics of mine are unsharpened. Straight from camera and are worse further away with the sharpness at f4
Is something wrong with the lens or is this how they are?
Why have it if you can't use it?

mudman
24-12-2011, 5:14pm
a question jules, were you at a didtance Greater than the minimum focus distance?
google the lens, it will give you the 'sweet' spot. that is the apetur and focal length for best performance.
i am sure that with your experience the answer to my question is 'yes'. just thought i would ask if only to jog your memory.
were these manually focused?

jjphoto
24-12-2011, 5:21pm
...These were focused right on the eye and I tried it a few times with the same results.

Did you use liveview (preferably with tripod and timer to fire the shutter)? It's the only way to test sharpness IMHO. Using AF allows for the possibility that the focus is actually in the wrong spot, which I suspect si the case.

Angle a ruler at about 45 degrees and focus on the middle of it (using AF or liveview). This will ensure that you see the actual point that is correctly focused. You may have auto focus accuracy issues but I hardly ever use AF so I can't really help you with that.

JJ

etherial
24-12-2011, 5:36pm
I agree, try to focus with liveview and see if you get a similar result. If you get sharp pics you may need to look at adjusting your cameras microadjust if it has it and/or at getting the lens checked out. I have that lens and find it is very nice right through the focal lengths and I use it wide open all the time. Microadjust for me did require a +3 adjustment to match my camera but that isn't much at all.


were you at a distance Greater than the minimum focus distance?
Minimum for that is 0.45m so that should be ok, but good thought.

arthurking83
24-12-2011, 6:01pm
Hey Julie.
Did you AF through the viewfinder? Was the camera on a tripod?


Two tests to do:

* on a tripod, do three tests through the viewfinder, after each focus attempt, manually focus away to completely blur papasmurf!
*still on the tripod, do at least two focus attempts using liveview using the same spot on papasmurf as the focus point like before.

one other thing to try is to use at least one other focal length.. either 50mm or less and 100mm or more as well.

Some zoom lenses can be very soft at different focal lengths(I'm assuming this is the 24-120/4 lens??).


As to why have it! .. because it still allows you to capture lower light images, even if they are going to be slightly softer.
Usually in lower light, the lack of contrast masks the effect of a less sharp image.
Although a larger aperture doesn't necessarily mean that you only use it in lower light.
DOF and super duper fast shutter speeds are the other reasons to have bigger apertures, in very bright light.
And on a technical note a faster sized aperture will always allow you better Autofocusing ability for a given lens type.

From a processing standpoint, as long as there is some good image data in the frame(that is, something to sharpen), sharpening will help to recover lost sharpness.

98kellrs
24-12-2011, 8:25pm
The 24-105 is supposed to be a good sharp lens right through the (aperture) range. Do a proper test using manual focus, live view etc which should tell you if the lens needs to go for service, or if you need to make any adjustments.

Not wanting to sound rude, but was a revival of a 600 day old thread necessary given you have already started your own thread?

41jas
24-12-2011, 9:28pm
a question jules, were you at a didtance Greater than the minimum focus distance?
google the lens, it will give you the 'sweet' spot. that is the apetur and focal length for best performance.
i am sure that with your experience the answer to my question is 'yes'. just thought i would ask if only to jog your memory.
were these manually focused?

I was close but actually zoomed in at 82mm on lens to frame. I actually took the first lot of photos that were at a distance of about 4 meters and that was worse.
No I didn't tripod it. The speed was fast enough at the setting. I first noticed this when I was doing portraits outside. Zooming in on them, they just weren't sharp enough for my liking which is why I did this test.
Do you think it would be worth taking it to someone that can do that microadjusting. Though it seems fine on the 50mm i tested. Wondering if the lens isn't a good one.

41jas
24-12-2011, 9:32pm
I agree, try to focus with liveview and see if you get a similar result. If you get sharp pics you may need to look at adjusting your cameras microadjust if it has it and/or at getting the lens checked out. I have that lens and find it is very nice right through the focal lengths and I use it wide open all the time. Microadjust for me did require a +3 adjustment to match my camera but that isn't much at all.


Minimum for that is 0.45m so that should be ok, but good thought.
These shots were focused with AF...When I have my camera out tomprrow I will give the live view a test...on a tripod and try is on AF first and switch it over to Manual and see if I have to fine adjust it. IF that is the case, can that be fixed? For doing portraits having the nice bokeh and inside where its darker you'd really wish using it at f4 would benifit having it.
Thanks for everyones advice.

41jas
24-12-2011, 9:33pm
These shots were focused with AF...When I have my camera out tomprrow I will give the live view a test...on a tripod and try is on AF first and switch it over to Manual and see if I have to fine adjust it. IF that is the case, can that be fixed? For doing portraits having the nice bokeh and inside where its darker you'd really wish using it at f4 would benifit having it.
Thanks for everyones advice.
( Seems to have attached to the quote so I have posted it again.)

41jas
24-12-2011, 9:35pm
Did you use liveview (preferably with tripod and timer to fire the shutter)? It's the only way to test sharpness IMHO. Using AF allows for the possibility that the focus is actually in the wrong spot, which I suspect si the case.

Angle a ruler at about 45 degrees and focus on the middle of it (using AF or liveview). This will ensure that you see the actual point that is correctly focused. You may have auto focus accuracy issues but I hardly ever use AF so I can't really help you with that.

JJ

Good idea...I will give that a go and see where the focus is at...Hopefully tomorrow or it will have to be after I get back from Tassie.

arthurking83
24-12-2011, 9:47pm
Hey again Jules.
I alredy posted in the other thread too(and I'll move them replies to here, to keep it all in the one place)

BUT!!! if you use LiveView + AF and you get misfocusing in any way .. it's time to take the camera back to the shop!

LiveView is not like normal AF.
Normal AF through the viewfinder is prone to the tiniest erros because of the way it works(using mirrors and stuff).
Live View is different(better!) in that the actual sensor is used to detect the contrast difference and hence focus to the best spot.

Unless your lens is 'broken'(which it isn't) if there is an error in Lv autofocus, then you have a defective camera!

What you would do with manual focus is:
Focus through the viewfinder as per normal and stop. Taking the exposure is optional .. not necessary but not going to hurt either.
What you then do is to switch to Lv mode and start the Lv function going. You won't mess up the focusing you previously achieved, so now you're in Lv mode but with the focusing you managed to achieve via the viewfinder.
This is where you now manually focus in super micro small adjustments to see if you can get the image on the review screen sharper!
Zoom in to just under 100% view on the review screen to see how accurate focusing was, and if you can achieve better results doing it manually.
There is a high possibility that if you AFed using the viewfinder, you may get slightly better focus via Lv mode and manually adjusting focus.

This can be normal depending on exactly where the focus spot was set too.
Just because you set the focus point on the eye, doesn't necessarily mean that the eye will be in focus, because there are other variables to deal with.

Can you post an image with the focus point highlighted too?
That is; are these images the full frame or crops? It all makes a difference unless all possible data is provided.

41jas
24-12-2011, 10:08pm
Would this make a difference to the camera if it seems ok with another lens?

I just bought this camera from an AP member. Its a 50D. I think what made me check it that the photos were very grainy. A few adjustments in the menu seems to have fixed this. At that time the eyes weren't real sharp is why I did this test. I will try and do it again and I might even try my 40D body as well...to see if ther eis a difference.
Thank you Arthur...you are a champ. x

etherial
24-12-2011, 10:26pm
Yes it will make a difference, the camera and lens can work with each other or against. That doesn't make any sense. In any case both can have errors, sometimes you get lucky sometimes not.

Microadjust each lens on each body. I find that my 24-105 is about +3 on both my bodies, but the 70-200 needs +10!! When I first got my 70-200 new it was terrible, needed something silly like +15 at 200mm and the opposite at 70mm. After sending it back to Canon it came back still requiring +10 on my 7D but at least it was consistent through the range. Now I can confidently use it wide open.

Do a search here for microadjust, there are a few posts about it (I posted a couple of threads about my adventures!). It is easy to do with the 50D and you can't break it, it is just a setting that you can change back to 0 if you find it gets worse.

arthurking83
24-12-2011, 10:35pm
Graininess can be from sharpening.

The higher the megapixel count, the more careful you need to be with sharpening.

41jas
24-12-2011, 11:26pm
Yes it will make a difference, the camera and lens can work with each other or against. That doesn't make any sense. In any case both can have errors, sometimes you get lucky sometimes not.

Microadjust each lens on each body. I find that my 24-105 is about +3 on both my bodies, but the 70-200 needs +10!! When I first got my 70-200 new it was terrible, needed something silly like +15 at 200mm and the opposite at 70mm. After sending it back to Canon it came back still requiring +10 on my 7D but at least it was consistent through the range. Now I can confidently use it wide open.

Do a search here for microadjust, there are a few posts about it (I posted a couple of threads about my adventures!). It is easy to do with the 50D and you can't break it, it is just a setting that you can change back to 0 if you find it gets worse.

Thank you sooo much for your help...I will look into it. Now I wish I had more time. I only have Christmas at home, then I will be flying to Tassie for 3 weeks. I will certainly look into it when I get home.

41jas
24-12-2011, 11:26pm
Graininess can be from sharpening.

The higher the megapixel count, the more careful you need to be with sharpening.

Didn't know that...I will look to what the camera is set to but I'm sure that is turned off.

mikew09
24-12-2011, 11:52pm
Hi Jules, I have just recently puchased a 24-105 and can't say I have noticed this when wide open. Just went through the shots I have taken at f4 and the best part of them are pretty sharp - the few not so spot on are user fault :-). I definitely suggest testing the lens for micro-adjust as my 24-105 seems pretty spot on but my 70-200 needs a +4 micro-adjust to hit the target focus point spot on.

About the grain or maybe noise you mentioned, it is a frustrating, but part of life when owning a 50D. Don't get me wrong, I love my 50D and it is a great camera but I struggled with noise issues coming from a 400D that was pretty forgiving with the lower pixel count. It is no secret that the 50D does suffer a bit on the noise side of things with the higher meg-p count. Having said that, it is a more than workable camera and once you get the feel for it the noise thing does not seem much of a problem anymore.
I have read pretty similar comments with owner of the 7D also.

Interested to hear how the tests turn out Jules but for me the 24-105 is one of the sharpest lens I have owned to date and I would say it is a smidgen sharper than my 70-200 L f/4 to be honest.

Hope it works out Jules, if you want I can post some un-sharpened shots from my 50D at f4 for comparison if that will help.

Brian500au
24-12-2011, 11:52pm
One other thing to check is to make sure if you have a second hand 50D there is not a micro adjustment already set for a 24-105 in the memory of the camera. I am not sure if the MA remembers the lens FL, or if it remembers a particular serial number of a lens. When I bought my 1DMKIII I was surprised to find it already had MA settings for most of the lens I was using, so I had to reset all the MA settings.

mikew09
24-12-2011, 11:59pm
Actually Brian500au, that is a very good point. Maybe just a need to zero the micro-adjust for the lens and go from there.

41jas
25-12-2011, 12:51am
If you micro set the lens at one point. Does it effect the other end of the lens? Might sound silly to those who know but I'm just trying to understand it all.
Also....does it effect the other lenses or does it remember that lens and knows when I have it on the camera?

arthurking83
25-12-2011, 12:54am
Micro adjust affect the entire focal length range.

if you have problems at say 85mm, and none at the longer and shorter end, and if you adjust the micro adjust to fix the 85mm length, it buggers up the rest of the zoom range!

41jas
25-12-2011, 1:03am
Micro adjust affect the entire focal length range.

if you have problems at say 85mm, and none at the longer and shorter end, and if you adjust the micro adjust to fix the 85mm length, it buggers up the rest of the zoom range!
Hummmm...thats what I was wondering. I might see how its going over the 3 weeks in Tassie Monday onwards and I'll go from there. Seems there is a commom problem though. Thanks for your help AK...x Merry Christmas hun..xxx

Brian500au
25-12-2011, 1:16am
MA remembers every different lens. The adjustments you make to the 24-105 will not affect 50 or 70-200 etc