Comments on Canon EF-S 18-55mm IS F/3.5-5.6
- Thread starter lioneldude
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gymak90
Senior Member
If AF missed the target, say the Hamilton F1 model, then somewhere else will be sharp.
From the picture I couldn't identify a sharp spot.
Is it really AF missing the target? Especially for the landscape shot, the camera shouldn't have any trouble in setting focus at infinity.
The lens doesnt pick up details. It's the sensor. You earlier said the lens was sharp. That is enough to ensure details are able to be seen, regardless of focal length. If focal length could affect sharpness, then no landscape shot with UWA lenses would be sharp.
What is wrong for checking 100% crop?
100% crop simply means a small section of the full 100% size of the picture is being displayed to you. In fact, this is the best way, argubly the only way to check picture sharpness. There is absolutely no degradation in image quality at 100% crop.
Besides, cropping has got nothing to do with focal length of the lens. A 55-250 changes the magnification and changes the picture entirely. If you are talking about cropping a picture then causing it to be overly enlarged, you should be talking about megapixels. Because pixels dictate resolution. Resolution governs the dimensions of the picture at full 100% size.
Reportage
Senior Member
Have you edited your pics?
hope you dont mind but with ten mins work can get something like this or better,
taken with 18-55mm iso200 at 55mm with 300D and cropped just few minutes ago...my scale models
Just me but i find this lens works best as a general lens rather then a specific use.
hope you dont mind but with ten mins work can get something like this or better,
taken with 18-55mm iso200 at 55mm with 300D and cropped just few minutes ago...my scale models
Just me but i find this lens works best as a general lens rather then a specific use.
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Hi Gymnak, thanks for your comments.
Thanks for pointing out about the UWA and sensor's role in focusing, in theory you appear to be correct. However, if you recall any experience with the kit lens, or especially the 55-250, the lens at the wide end focuses horribly at long distances... most of the time it won't even confirm (or take ages to).
Surely the sensor is at work, but the sensor still takes input of lines from the glass. If these inputs are not very clear (too small in this case), the sensor may just miss. And well, infinity has a small range to work with too, its only ~infinity. Just my guess perhaps, I could be wrong.
Also about the 100%, nothing wrong with checking it, I do it all the time, on every lens (including my IS Kit), in fact I tested my IS kit lens on a test chart (maybe even going to do one more test with upsampling) & sent it in for calibration due to a 1cm (on test chart) front focus, I bet the CSC people are frowning at it right now.
But I am saying, don't be too fussy about it with this lens, because you probably should not need to crop photos taken with this lens if framed properly, agree? And if you are cropping photos with this lens, its somewhat indicative that you need a longer focal length. Hope I clear my drift.
Maybe I'm just too impressed with my IS kit lens that I got a little fanatic with my arguments here, my apologies if I've too hastily dissed any part of the conversation carelessly. =)
engrmariano
Senior Member
im satisfied with my 18-55 IS
lioneldude
Senior Member
Have you edited your pics?
hope you dont mind but with ten mins work can get something like this or better,
taken with 18-55mm iso200 at 55mm with 300D and cropped just few minutes ago...my scale models
Just me but i find this lens works best as a general lens rather then a specific use.
Hi i have not edited it. I'm still learning on how to use photoshop etc. Only know certain basics like levels, curves, hue, saturation, etc. Thanks for pointing out.
Where can i find this test chart? The focusing is off due to wear and tear?
I designed my own test chart to my own liking. =) Its definitely not up to ISO 12332 (or whatever number) standards but its enough for me to determine if I'm satisfied with the lens. Basically just sharpness, CA fringing, focus, and gray contrast. I don't know how to test colors, but its usually non-issue since you can more or less post process.
Whether wear and tear can mis-calibrate the lens, I'm not very sure, maybe ask the seniors around here. =)
Test charts basically put an objective measurement to the lens (such as front focusing, measured with a number). However, in reality you do not need to go to such a great extend. Just shoot on any printed matter (i prefer black and white, not newspaper as it is gray) and you probably can get a good but 'subjective' feel of your lens' focusing issue and sharpness.
lioneldude
Senior Member
I did not off the IS when its on the tripod/and didnt use cable release. Could this be the problem?
I did more test by shooting far with both the 18-55 and 55-250 lens. Will look at it again.
No, it shouldn't be THAT obvious, unless you're a super picky user. By the way whats the ISO? I seriously suggest you shoot something with better lighting. Go out and do some flower macros with your 55mm, you should be able to get 1:3 or 1:4 magnification cant remember... Try shooting at F5.6 again as well, maybe you just hit a bad spot in the lens.
By the way, you should know that this lens is worst at 55mm, but having said that, its not unusable, and does it really concern you? You mentioned having the 55-250? 55 on that lens is awesome. =)
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samchong
Senior Member
Of course IS is not require when the camera is on the tripod.The camera will shake when your finger pressing the shutter. I had experience this when taking the night shot .....
please try again with this, good luck ........:lovegrin:
lioneldude
Senior Member
Thanks for the tips/comments. I will take note and do more tests this xmas weekend. Worse come to worse i will send it to CSC for calibration.
lioneldude
Senior Member
Ok this time i shot the hamilton model with Tripod, Shutter Timer 2 sec, Mirror Lockup, Aperture Priority Mode at F/7.1, IS is set to OFF
NOTE: All shots Auto Focus point is set to middle point, and aimed at the center of Mercedes Benz logo on Hamilton's helmet. Window reflection can be seen in helmet.
Shot in RAW format, then used Canon's DPP software to raise brightness to comparable values
At 55mm, 0.5 Sec Shutter, F/7.1, ISO-100
full pict http://i11.photobucket.com/albums/a174/lioneldude/IMG_1360-55mm-editMedium.jpg
At 35mm, 0.3 Sec Shutter, F/7.1, ISO-100
full pict http://i11.photobucket.com/albums/a174/lioneldude/IMG_1370-35mm-editMedium.jpg
At 24mm, 1/4 Sec Shutter, F/7.1, ISO-100
http://i11.photobucket.com/albums/a174/lioneldude/IMG_1378-24mm-editMedium.jpg
Comments? Is it better now?
NOTE: All shots Auto Focus point is set to middle point, and aimed at the center of Mercedes Benz logo on Hamilton's helmet. Window reflection can be seen in helmet.
Shot in RAW format, then used Canon's DPP software to raise brightness to comparable values
At 55mm, 0.5 Sec Shutter, F/7.1, ISO-100
full pict http://i11.photobucket.com/albums/a174/lioneldude/IMG_1360-55mm-editMedium.jpg
At 35mm, 0.3 Sec Shutter, F/7.1, ISO-100
full pict http://i11.photobucket.com/albums/a174/lioneldude/IMG_1370-35mm-editMedium.jpg
At 24mm, 1/4 Sec Shutter, F/7.1, ISO-100
http://i11.photobucket.com/albums/a174/lioneldude/IMG_1378-24mm-editMedium.jpg
Comments? Is it better now?
samchong
Senior Member
Ya this look better than before, you can use sef timer for the shot if the time is not too long :thumbsup:Ok this time i shot the hamilton model with Tripod, Shutter Timer 2 sec, Mirror Lockup, Aperture Priority Mode at F/7.1, IS is set to OFF
NOTE: All shots Auto Focus point is set to middle point, and aimed at the center of Mercedes Benz logo on Hamilton's helmet. Window reflection can be seen in helmet.
Shot in RAW format, then used Canon's DPP software to raise brightness to comparable values
At 55mm, 0.5 Sec Shutter, F/7.1, ISO-100
full pict http://i11.photobucket.com/albums/a174/lioneldude/IMG_1360-55mm-editMedium.jpg
At 35mm, 0.3 Sec Shutter, F/7.1, ISO-100
full pict http://i11.photobucket.com/albums/a174/lioneldude/IMG_1370-35mm-editMedium.jpg
At 24mm, 1/4 Sec Shutter, F/7.1, ISO-100
http://i11.photobucket.com/albums/a174/lioneldude/IMG_1378-24mm-editMedium.jpg
Comments? Is it better now?
gymak90
Senior Member
You mean at the wider side of your 55-250, the lens won't (or take ages to) focus at far away objects?
If that's the case, you should blame the lens and it's focusing speed. Like I've said earlier, once subjects are far away, most likely the lens will have to focus at infinity. Check your lens on where infinity is, probably about 15m or further. And beyond that range, everything should be sharp.
There are many factors affecting focusing. The sensor only picks up the image. But it is the focusing mirror and that controls focusing. Unless the subject you're focusing is really small, then there might be some difficulty. Here is where small and many focus points help.[/QUOTE]
Well yes you can say that people sometimes crop so as to get a more narrow view, where a longer lens would have equally done the job.
However there are sometimes where cropping is done to change picture dimensions, or make the view more concentrated on the subject.
Framing properly is something we should all do, but in the heat of the moment, it's hard to do.
Just to check, any PP done on the picture? It looks a bit "over-sharpen" for a 100% crop picture.
that was taken with my 18-55 IS at f5.6,55mm.
100% crop
i find it quite a bit sharper than my tamron 18-200.
Adding a lens hood might help ( the degree varies ).
The 2 kit lens is not very resistant to flare (since you mentioned the lens is more or less facing the sun ), and stray light will reduce the contrast and the picture will appear less sharp.
There's another thread that mentioned that adding a cheap filter will cost some loss of sharpness too. And the effect is especially pronounced in your case (of facing strong light source). You didn't mentioned whether any filter was ON for the sentosa picture (Althou you mentioned tokina UV filter for another picture), so not sure if it is the cause. But your picture appears to have a white screen over it, which is likely caused by flare.
There's a picture which I took at Chinese Garden w/o filter (not sure if hood was on). The colour seems better right? Try to avoid strong light source in front, and use Hood whenever possible. It may help.
original
100% crop
The 2 kit lens is not very resistant to flare (since you mentioned the lens is more or less facing the sun ), and stray light will reduce the contrast and the picture will appear less sharp.
There's another thread that mentioned that adding a cheap filter will cost some loss of sharpness too. And the effect is especially pronounced in your case (of facing strong light source). You didn't mentioned whether any filter was ON for the sentosa picture (Althou you mentioned tokina UV filter for another picture), so not sure if it is the cause. But your picture appears to have a white screen over it, which is likely caused by flare.
There's a picture which I took at Chinese Garden w/o filter (not sure if hood was on). The colour seems better right? Try to avoid strong light source in front, and use Hood whenever possible. It may help.
original
100% crop
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Actually I'm not sure what exactly the problem is with the 55-250... all copies seem to exhibit the same problem. At exactly the 55 point, it is really painful to lock onto focus at a far away object. However, the image will already be in focus... it just won't confirm (no hunting at all). If at that time you switch to MF and shoot the shot, it should be in good focus. By 70mm the problem is gone, its just weird.
Otherwise, the AF speed is pretty fast and silent for the lens of its class. No USM speed, but say 70% there. Able to lock on even at night with just street lights. =) Running OT~!
The IS kit lens focuses pretty well too. And I'm only on a 350D body, if the points laid on correct details, should have no problem.
Anyway, yea I agree framing isnt exactly easy on the field, but I guess my point was that, it shouldn't be that far off that you need to use more than a 50% crop thus no need to be so hard for a lens of this class. Honestly I haven't seen any standard lens of any grade, even L, beating the MTF figures of this lens. Do you know of any?
lioneldude
Senior Member
Took all my shots with the Tokina UV filter. Did some test on with and without filter but they appeared the same to me. Will double check on this again. BUT i do agree that a cheap filter will affect the shots esp if the sun is in front of you.
Anyway tested BMW F1 car with Filter and Without Filter (TOKINA UV Filter). I see no diference.
ISO-200, 0.6 sec, F/7.1, Tripod, 2 sec shutter release, mirror lockup
With Filter
Full Photo
http://i11.photobucket.com/albums/a174/lioneldude/IMG_1395-edit-withFilterMedium.jpg
Without Filter
Full Photo
http://i11.photobucket.com/albums/a174/lioneldude/IMG_1396-edit-woFilterMedium.jpg
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