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soft shots?
I've recently graduated from the P&S world to a Canon SL1 with kit lens and 40mm pancake.
I bought the camera just before a recent trip, so I really didn't have a lot of time experimenting with it.
There was a link in this forum to print a sheet for lens focus testing, and on a tripod, to my eye, it looked fine.
In camera, my shots looked OK, using the center focus point only and recomposing.
When I got home this weekend, I was disappointed to see a lot of shots looking soft.
Some might have been my own fault using too large an aperture for indoor shots with flash, shortening the DOF with multiple people in the shots, but now I'm concerned that there is an issue with the camera/lens.
Is there something I can look at, or just send them to Canon and see what they say about calibration?
Thanks in advance.
I bought the camera just before a recent trip, so I really didn't have a lot of time experimenting with it.
There was a link in this forum to print a sheet for lens focus testing, and on a tripod, to my eye, it looked fine.
In camera, my shots looked OK, using the center focus point only and recomposing.
When I got home this weekend, I was disappointed to see a lot of shots looking soft.
Some might have been my own fault using too large an aperture for indoor shots with flash, shortening the DOF with multiple people in the shots, but now I'm concerned that there is an issue with the camera/lens.
Is there something I can look at, or just send them to Canon and see what they say about calibration?
Thanks in advance.
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If you have any links to full resolution image examples, which also have full EXIF, it would be helpful in isolating the cause(s).
For the reason why focus and recompose can cause focus errors:
http://visual-vacations.com/Photography/focus-recompose_sucks.htm
http://www.bobatkins.com/photography/technical/focus_recompose.html
http://www.mhohner.de/essays/recompose.php
Adding an electronic flash which has a focus-assist lamp can improve AF accuracy tremendously in indoor and darker conditions.
These are the steps I take to check a lens for focus accuracy:
1) Basic AF accuracy is best accomplished using a flat target, i.e. a brick wall or other large textured surface. If a camera/lens cannot accomplish this task, it has no chance of passing any subsequent AF tests including real world use. Make sure that the target is at the typical distance for your normal use of the lens, meaning that a long focal length lens that you would normally use for wildlife at a distance should be tested at that same distance for AF accuracy. Always test a lens at least twice Minimum-Focus-Distance (MFD). Lenses rarely do their best at MFD (the exception being true "macro" lenses.)
If a lens shows consistent front or back focusing with the wall test, then use micro-focus adjust technique until you get consistent accuracy. If the particular camera body does not have a micro-focus option, it should be serviced, or the lens should be serviced. If you have consistent results with all lenses then send in the camera. If the problem only exists with a particular lens, it's the lens that needs service.
If the lens passes the wall test, proceed to the next test. If the lens fails the wall test and you cannot gain accurate AF with micro-adjust, send the lens back to where it came from or explore camera issues.
2) A fence line or similar, shot at an angle to the subject. Put a singular strong-contrast target on the top of the middle post and use a single focus point in the camera to focus against the target. This shows focus accuracy and/or how easily distracting for/aft objects influence AF accuracy (compared to the above wall shot). It also shows bokeh tendencies at different aperture settings.
3) A focus target/chart like in the following:
http://regex.info/blog/photo-tech/focus-chart
I do recommend testing these charts at twice minimum focus distance or greater. Most lenses, especially most zoom lenses, do not do their best at MFD. True macro lenses are the major exception.
4) A US stop sign, or similar very high contrast signage, both centered and off center and to the side and/or corner. This can show chromatic errors and off-axis errors.
5) Now just shoot "typical" subjects for your use of the lens(es). It's important that the lens perform correctly for your intended uses.
Moderator of the Cameras and Accessories forums
I'll look at your suggestions.
P&S cameras have small sensors and short lenses with wide depth of field.
With a small sensor, it is difficult not to have everything in focus, and
photographers wanting shallow DOF gravitate toward bigger sensors and
larger apertures. A bigger sensor is the best upgrade to improve the technical
quality of one's photographs, however, the larger the format, the more attention
to detail needed.
I plan on taking some shots tomorrow in good daylight with fast enough shutter speeds and making notes of exactly where the focus points are for each shot, and checking them out on my computer.
I'll post an update with links if my concerns persist.
By the way, does anyone have any recommendations on what I can read for tips on popup flash shooting to get better results?
At this point, I'll still be using the popup flash. Yeah, I know how much better speedlights are, but for now it will have to do.
"You miss 100% of the shots you don't take" - Wayne Gretzky
I'll have to see what the camera is using for defaults, but I usually add some sharpening in LR.
Another thought is that anything other than viewing full 100% pixel size can look soft, or otherwise odd.
Here's what I generally use for JPEG output on my Canon bodies. They're pumped up a bit, but the JPEG's are mostly ready to go this way. RAW images are left unaffected by this (I record separate RAW and JPEG images with each shot). The "3" setting (of 7) gives a sharp enough image that I don't usually don't need to change it in editing.
"You miss 100% of the shots you don't take" - Wayne Gretzky
I'm using Lightroom. It brings in the lowres thumbnail for speed until you open it up full-window.
Then you see it bring it in full-res.
"You miss 100% of the shots you don't take" - Wayne Gretzky
I'll use both the kit and 40 mm pancake.
I really hope it was just the low light situations and not an issue with the camera or lenses.
Most photographers have been where you are now. I went through
this in the early 80's when I upgraded from a fixed mount lens shutter
camera to an SLR. I have a student now who recently upgraded from a
Canon G10 to a Fuji XE1. His photographs have improved, however, he
has really had to step up his game.
First shot with 18-55 kit lens at 3.5.
Second shot with 40mm pancake at 2.8.
They are full size--I didn't know whether or not to resize them regarding forum rules, since it might make them harder to analyze.
If so, I'll do it.
I just want to make sure that the defect is with my technique and not the camera.
P&S was so much easier not having to worry about DOF when trying to get a sharp focus.
I know there's a learning curve--I'm just disappointed that I got the camera just before a trip, and a lot of the shots could have been sharper.
[post=1874576]Procedure for testing accurate focus[/post]
Perform the first test (brick wall test) to determine front focus, back focus and accurate focus.
The test chart shot at such a strong angle cannot be used for determining focus. There is a reason that I shoot a test chart as item #3, and that reason is that a test chart often only shows how distracting subject matter can affect focus.
To determine accurate focus you really must photograph something extremely simple, like the brick wall test. If the brick wall test fails for focus accuracy, there is something wrong with either or both the camera and lens. Fortunately you have two lenses which should allow you to determine what's really happening, but start with the brick wall test.
Moderator of the Cameras and Accessories forums
Kit @ 8
40 @ 2.8
40 @ 8
I didn't know what f/ to use--I included a few.
If you want a shot from further back, let me know. They were from about 6 feet.
If you want a "standard" brick wall, I'm going to need to search for one. The burbs around me don't have any.
I really appreciate the help.
Image sharpness does not seem to be a problem with either lens. The Canon EF 40mm f/2.8 STM is sharper wide open than the "kit" EF-S 18-55mm IS STM, but that's to be expected as kit lenses are made to be inexpensive and highly affordable, sacrificing ultimate image quality for versatility and low cost. The 40mm f/2.8 STM is just a very nice lens, by comparison.
A lens with a maximum aperture of f2.8 (or larger) also actuates the high-precision mode of the center AF dot. In high-precision mode the AF is twice as accurate as the other AF sensor locations. The center AF sensor location is also the only cross-type sensor, allowing focus detection on either the horizontal or the vertical edge of the subject. All of the other sensor locations are both less sensitive and they are "line" type AF sensors, meaning that they only detect a subject's edge in one direction, either vertical or horizontal detection only (depending upon the design specification).
I suspect, but do not know for sure, that the 9-point AF system of the SL1 is probably similar to that used in the Canon 20D, as shown here:
http://k53.pbase.com/o4/67/574167/1/55053704.web20DFocusSensors.jpg
In low light, you may wish to use "Live View" mode and magnify the area of the screen you wish to be in sharpest focus, then manually focus the lens. It is slower to focus this way but in low light may yield better results.
As I mentioned previously, an external flash with an AF Assist light, and using a suitable flash modifier, can work minor miracles in improved image quality when the ambient light is low, like at night and indoors anytime.
To answer your previous question about improving the quality of results from the on-board flash, if you position a diffuser in front of that flashtube that will help a little, but only a little. A diffuser will cost you some light output as well.
Things really improve when you use an external hotshoe flash with an appropriate flash modifier, and then things get "interesting" when you can start using flash off the camera. Multiple flashes just increase the possibilities for creative lighting.
In the meantime for indoors, try using whatever form of extra light you can find. Try to keep the color temperature the same as other light in the scene. (Try not to mix fluorescent and tungsten bulbs, for instance.)
Moderator of the Cameras and Accessories forums
I'm trying to find topics on achieving better focus, and there are many opinions out there, but several common themes keep coming up.
I'll keep experimenting and see how things go.
Again, I really appreciate you taking the time.