pictures not sharp

[ron moore]

hello everyone

I am using a 500D with a Tamron 18-270 lens and some of my pictures are not very sharp
is it the way that i am setting the camera up or is the lens that is the problem. I have attached pic for your comments

i dont think my pic uploaded can someone tell me how to please

regards ron moore

[ianpinion]

Hello Ron,

Firstly, for more help on how to upload your photograph click here.

Now the images you've been producing with this lens that you're not happy with, do you find the focusing looks a little soft when you're shooting with the focal length over 220mm or under 50mm? If so, then this could be down to the lens I'm afraid. You see the wider the focal length range is for your lens the more compromised the optical quality of the lens becomes. You see it's trying to be all things to all men and in doing so something has to give. The problem the lens makers have is at the wide end they've got to try and prevent lens barrelling and at the other vignetting occuring in higher contrast conditions amongst many other making it almost impossible to keep the lens' dynamics optically sound. This is why you may have heard that the images produced using prime lenses with a fixed focal length are usually much crisper and punchier. It's because the manufacturer can optimise the optical quality of the lens becuase the only parameter that can alter is the aperture value. With a zoom lens the focal length can also be changed.

So with a zoom lens you will find that they perform best around the middle focal lengths and aperture values and as you move towards the extremities the performance tails off. So if you were using your lens at say a focal length of 135mm between f/6.3 - f/11 you will find that it produces pretty sharp images, because you'll be in the lens' 'sweetspot', but as you move away from the mid point in either direction the quality starts to gradually decrease.

Now of course, if you're anything like me, you'll predominantly want to use this lens at either 270mm or 18mm and if that's the case then you will have to accept that the image quality will suffer. You can always try to sharpen the image in photoshop afterwards using the unsharp mask and this will improve things. My other recommendation would be not to use either very small or very wide apertures as again you may find if you did that it again would impact on the optical quality of your images. Certainly, we are told to use f/16 for landscapes to ensure that our depth of field remains wide enough that everything remians in focus from front to back in shot, but you will also start to detect what is termed diffraction, that basically makes your images look slightly off focus. What happens is that the light as it passes through the lens can get reflected off the sensor surround and then reflected back towards the sensor off the aperture blades creating a double image if you like.

Anyway, post up one of your photos and we'll have a look at them and give you an honest opinion, but next time you're using this lens just bear these points in mind and see how you get on.

[ron moore]

hello ian p

the photo is in my photos page
please tell me if my settings are wrong
what would you suggest as a beginners all round lense that i could use all of the time
for every day photography in a decent price range


ron moore

[OldBoy]

Is this the photo you were trying to post?



It looks like the focal point isn't on the face and your shutter speed was 1/250s. You are best using spot focus when you want to focus on a subject, and you speed is a bit slow if handheld, would be better at 1/500s. I'm guessing you had walked up the hill/slope before turning to take the photo, if so then your breathing could cause the problem. You can use shutter speeds of 1/30s handheld, but you need to be sure you can hold the camera rock steady to get a good shot.

To upload a picture, click on it in your gallery and when it opens medium size, you should see a plus sign top right corner above your picture, right click on this and from the dropdown list click on copy shortcut, then open the thread you wish to post your picture in, cilick on the insert image icon(looks like a mountain), and in the window that opens right click in the box and select paste from the dropdown list.

[ianpinion]

Here you go Ron, I'll post it into the thread for you.


Which focus point was the camera using, Ron? To me it doesn't look as though the focus point was on your wife and as such it's focused on a point in the background. Also because it didn't focus on you wife and you're using a wide aperture, it means your depth of field is shallower too. Am I correct in thinking that you were trying to get her in focus and throw the background out of focus? If so, you're right to use your widest aperture, but it also helps if you zoom in tighter on your subject.

[amk1977]

Hi Ron

Its looks like the auto focus locked onto the tree behind the subject, as the stones between the two shadows cast on the path behind her, look to be in focus.

Aside from the AF inadvertently locking onto the tree, it could be that as you half depressed the shutter release and focused on your wife, if the camera wasn't in continuous servo mode (constantly monitoring/tracking and adjusting the focus) that as she continued to walk towards you, she automatically moved beyond the focal plane and defocused herself - if that makes sense.

The lens you have is a good all-purpose lens, with a very useful zoom range, going from wide angle to super telephoto. This allows you to go from landscape to close up shots without the need to change lens. Although there will enevitably be compromises in terms of optical quality and focus speed from covering such a vast zoom range, its still capable of producing very nice results.

If its your only lens for your camera and are looking to add to your kit, then I would strongly recommend the Canon 50mm f/1.8 MKII. Excellent for portraiture and also as a general walk about lens too. Obviously you have no zoom capabilities as its a prime/fixed focal length lens but, the wide aperture allows for really shallow depth of field and its also a great low light lens. Razor sharp too.

[ron moore]

hello everyone
thanks for all your comments, are you all telling me that the lense is ok and i need to
adjust my settings because i was thinking of selling it and buying something else

ron moore

[ianpinion]

Ron, the lens is fine for what you want at the moment. Just be aware of it's strengths and weaknesses and work around those to get the best you can from it. The problem with your shot is down to user error, not the lens.

However, there will come a time when you feel it is time to upgrade to a better quality lens, but this will be when you cannot attain the quality of image you want from it. Until then, keep using it and learn how to get the best out of it.

[KeithT]

Several factors make for a sharp image. Good lighting is the most obivious,and good holding technique is important too. OldBoy mentions focus point, and perhaps you should look at how you have set this up. I have always advised the use of centre point focussing and use nothing else myself, simply because we normally aim at our subject to achieve focus. Also aperture: make sure your aperture is giving you fast enough shutter speeds so that it illiminates hand shake — a big cause of unsharp images. As a rough guide for hand held shots, make sure your your shutter speed equates with 1 over the focal length of your lens. For example, if you have a 50mm lens on board, your shutter speed should be at least 1/50s. Your aperture should be set to its optimum for front to back sharpness and as a guide that is usually about 2 or three stops up from your widest aperture. If that is f/4 then shooting at f8 - f11 will optimise your lens sharpness. My advice is to shoot with AV mode, so that you can control the aperture very quickly. If you find you need a bit more shutter speed you can always up the ISO — something that couldn't be done so easily with film, though us oldies did push and pull ISO levels at times.

[amk1977]

Good advice from Ian and Keith here. There are a lot of factors you have to take into account when taking a photo. When you first start out in photography, it can be a bit bewildering knowing when to use certain settings but, in time it will become clearer until its virtually second nature. Obviously you can set the exposure mode to automatic or one of the other pre-programmed modes (portrait, landscape, night time, etc.) but, you're letting the camera do 95% of the work for you and will not get the most from it.

The way I taught myself was that were is essentially a balancing act between available light, aperture of the lens, shutter speed and ISO. If you're not familiar with these, my advice would be to read up or watch some online tutorials on what each does, how they affect an image and how they interact with one another. Some (like the aperture) have a couple of effects such as affecting the amount of light entering, the sharpeness and depth of field.

I'll expand a little on what Keith mentioned and give you an example. Say you were shooting pictures indoors and the lighting is a bit dim, your shutter will need to be open for a longer period of time, than it would do in bright lighting, in order to get the picture correctly exposed. Now, any movement by you or the subject during that time, will result in motion blur. Slower shutter speed = bluring of moving objects. Fast shutter speed means freeze framing of moving objects.

However, you do have the option of raising your ISO, which is basically the sensitivity of the sensor. By making the sensor more sensitive, you don't require so much light hiitting the sensor in order to get the same exposure. The only downside to raising ISO is that noise begins to enter the image, particularly in shadows/dark areas. Up to a point, it isn't noticeable and a lot can be removed in post processing with software like Photoshop. Experimenting with the ISO is important. I'd suggest setting the camera on a tripod and shoot the exact same image at ISO ranges from 100 - 6400, then review them. Make a mental note of where you think the noise level becomes too much to be worthwhile keeping the photo. Then try to keep within that boundry.

As Ian says, your lens is fine for what you want it for and should be no problems with it. 99% of all photography "errors" are to do with what's holding the camera, not the camera itself lol.