Sharpness advice

[swoosta]

Hi
I have just purchased a Canon 70-300 USM IS lens an have taken a few test shots. I can't get really sharp images on it ...see image.


any tips?
(looks worse in a larger photo)here .... http://www.flickr.com/photos/swoosta/5917905051/

[swoosta]

Camera Canon EOS 40D
Exposure 0.01 sec (1/100)
Aperture f/5.6
Focal Length 300 mm
ISO Speed 200
Exposure Bias 0 EV
Flash Off, Did not fire
Orientation Horizontal (normal)
X-Resolution 72 dpi
Y-Resolution 72 dpi
Date and Time (Modified) 2011:07:07 16:03:48
YCbCr Positioning Co-sited
Exposure Program Aperture-priority AE
Date and Time (Original) 2011:07:07 16:03:48
Date and Time (Digitized) 2011:07:07 16:03:48
Metering Mode Multi-segment
Sub Sec Time 00
Sub Sec Time Original 00
Sub Sec Time Digitized 00
Color Space sRGB
Focal Plane X-Resolution 4438.356164 dpi
Focal Plane Y-Resolution 4445.969125 dpi
Custom Rendered Normal
Exposure Mode Auto
White Balance Manual
Scene Capture Type Standard
Macro Mode Normal
Self Timer Off
Quality Fine
Canon Flash Mode Off
Continuous Drive Continuous, Low
Focus Mode Manual Focus (3)
Record Mode CR2+JPEG
Canon Image Size Large
Easy Mode Manual
Digital Zoom None
Contrast Normal
Saturation Normal
Metering Mode Evaluative
Focus Range Not Known
Canon Exposure Mode Aperture-priority AE
Lens Type Canon EF 70-300mm f/4-5.6 IS USM
Short Focal 70 mm
Focal Units 1/mm
Max Aperture 5.7
Min Aperture 45
Flash Activity 0
Flash Bits (none)
Zoom Source Width 0
Zoom Target Width 0
Manual Flash Output n/a
Color Tone Normal
SRAWQuality n/a
Auto ISO 100
Base ISO 200
Measured EV 5.50
Target Aperture 5.7
Target Exposure Time 1/102
White Balance Cloudy
Slow Shutter None
Sequence Number 0
Optical Zoom Code n/a
Flash Guide Number 0
Flash Exposure Comp 0
Auto Exposure Bracketing Off
AEBBracket Value 0
Control Mode Camera Local Control
Measured EV2 5.5
Bulb Duration 0
Camera Type EOS High-end
NDFilter Unknown (-1)
Canon Firmware Version Firmware Version 1.1.1
Serial Number 1330725445
Camera Temperature 24 C
Camera Orientation Horizontal (normal)
Focus Distance Upper 1.64
Focus Distance Lower 1.53
Color Temperature 5200
Firmware Version 1.1.1
File Index 2078
Directory Index 100
Lens Model EF70-300mm f/4-5.6 IS USM
Canon Model ID EOS 40D
AFMode Off (Manual Focus)
Num AFPoints 9
Valid AFPoints 9
AFArea Widths 97 97 97 97 97 97 97 97 97
AFArea Heights 98 98 98 98 98 98 98 98 98
AFPoints Selected 4
Original Decision Data Offset 0
Bracket Mode Off
Bracket Value 0
Bracket Shot Number 0
Raw Jpg Size Large
WBBracket Mode Off
WBBracket Value AB 0
WBBracket Value GM 0
Live View Shooting Off
Internal Serial Number J0832118
Dust Removal Data (Binary data 1024 bytes, use -b option to extract)
Tone Curve Standard
Sharpness 3
Sharpness Frequency n/a
Sensor Red Level 0
Sensor Blue Level 0
White Balance Red 0
White Balance Blue 0
Picture Style Standard
Digital Gain 0
WBShift AB 0
WBShift GM 0
Measured RGGB 512 1024 1024 466
Color Space sRGB
VRDOffset 0
Sensor Width 3944 (40-3927 used)
Sensor Height 2622 (23-2614 used)
Black Mask Left Border 0
Black Mask Top Border 0
Black Mask Right Border 0
Black Mask Bottom Border 0
Color Data Version 3 (40D)
White Balance RGGB Levels 2378 1024 1024 1346
Color Temperature 6017
WB_ RGGBLevels Measured 2251 1021 1025 2203
Color Temp Measured 4030
Raw Measured RGGB 255677 527333 505598 226249
Exposure Level Increments 1/3 Stop
ISOSpeed Increments 1/3 Stop
ISOExpansion Off
AEBAuto Cancel On
AEBSequence 0,-,+
Safety Shift Disable
Flash Sync Speed Av Auto
High ISONoise Reduction Off
Highlight Tone Priority Disable
Lens Drive No AF Focus search on
Lens AFStop Button AF stop
AFPoint Selection Method Normal
Superimposed Display On
AFAssist Beam Emits
AFDuring Live View Disable
Mirror Lockup Disable
Shutter Button AFOn Button Metering + AF start
AFOn AELock Button Switch Disable
Set Button When Shooting Normal (disabled)
Dial Direction Tv Av Normal
Focusing Screen Ef-A
Add Original Decision Data Off
Live View Exposure Simulation Disable (LCD auto adjust)
Add Aspect Ratio Info Off
Compression JPEG (old-style)

[littlebro]

Shutter speed far too low for presumably hand held at a focal length of 300mm, someone here will give you more technical advice but I think the general rule is shutter speed should be approx three times the focal distance. It would have been ok on a tripod though also at the top end your lens will be softer. BTW the exif data is in the link bottom r/hand corner on Flickr.


Right I shall wait for someone to shoot me down. LOL.

[GeoffWessex]

I don't know about 'Technical Advice', but if you're using a 300mm lens, you should be using nothing slower than 1/300th.
It follows that 'n' (mm) focal length should use nothing slower than 'n' (1/'n'th) shutter speed, e.g. 50mm lens - 1/50th (later cameras, with Image Stabilization, would allow an extra stop - i.e. slower - like 1/25th).

However.... although you're using 300mm, the crop factor on a Canon 40d would be +1.6.... so you're effectively using about 460mm..... which would limit you to 1/500th. So your 1/100th is about two stops too slow on the shutter speed. This, of course, is assuming you're shooting 'hand-held'. Image Stabilization, which this lens has, would have allowed an extra 'stop' or two of shutter speed. But I wouldn't guarantee it.

Also, if this kind of subject matter really interests you, you should invest in a macro lens - your 70-300mm lens would have been a long way from the subject on this shot - and there could have been some very small movement in the flower/insect. A proper macro lens, giving 1:1 magnification (at maybe 100mm) would have allowed you to get within 15" or so. You shot shows a lot of unnecessary foliage - the main subject(s) take up about a quarter of the image - showing that you've been forced to shoot from quite a long range.

Just to add to the problem, you shot this (out of necessity) at the largest aperture your lens could give you (f/5.6). Apart from not really being large enough to give a good shutter speed, that's at the extreme end of the optical performance of the lens (when it's set to that length).... all lenses work at their optimum performance if the aperture used is in the middle of the range - which would be about f/8 or f/11 in this case.

The answer, of course, is a tripod..... though the IS is better switched off when the camera's tripod-mounted.

One other thing.... looking closely at the large version of the image, it appears that the focus is slightly behind the insect and flower - like on the leaf at the bottom. You were manual mode focus.... so you may want to check the accuracy of the viewfinder, to match your eyes.... you can alter the 'dioptre' (magnification) in the viewfinder to suit you better.... worth doing a few test shots in manual focus.

[deena]

There is a rule of thumb which links focal length & shutter speed to avoid blur when taking hand-held shots. Generally your shutter speed should be the same or higher than your focal length to avoid camera shake blur.

In this photo, you have used 300mm focal length but this is really equivalent to 480mm when you take into account the 1.6x crop factor for your camera. So a minimum of 1/500 sec would have given you a much sharper image.

In practice if you brace your body against a wall or tree etc and use a smooth shutter release you can sometimes get away with a slower shutter. Also if your lens has IS or VR then you can usually use a slower shutter speed. Of course using a tripod eliminates this problem but then with a moving insect you have to take into account how fast the insect is moving!!A tripod in this instance is only valuable if you know EXACTLY where the insect will land .......or a lot of patience

[swoosta]

Thanks for all the help

[deena]

Didnt mean to sound repetitive after Geoff. We posted at the same time. I agree, the f/8 or f/11 would have also made a slight difference.

[swoosta]

Can you explain more about the optimum performance at the middle of the aperture, does this apply for only close-up photography?

[deena]

It applies to all lenses. Each lens has a 'sweet spot' which refers to the aperture setting that yields the best overall sharpness. Here is an interesting article on the subject. Hope you find it useful

http://www.digital-photography-schoo...ens-sweet-spot

[ianpinion]

The sharpness would also improve if you were using a focal length of between 130mm and 200mm, because again these fall between the focal sweetspot for your typical 70 - 300mm lens. All zoom lenses are a little bit soft at their extremeties, unless you're paying mega money for top quality optical glass.