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Old May 8, 2008, 11:07 AM   #1
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Greetings,
I'm new to the Canon SLR world and I've recently got a canon XSI. I've been reading about it and there are some complaints about front focusing issues and soft photos. I'm too much of a rookie to know if my camera suffers from any of those symptoms.
Therefore, i'm begging for some help. I was wondering if anyone wouldn't mind evaluating a few photos and letting me know if the camera seems to operate normally. There does seem to be a bit of chromatic aberration when you blow up an image to view at 100% but uncertain if that's normal, or if it may be camera or lens related.
Pictures are taken with the XSI and the kit lens in auto and landscape modes.
Thank you all in advance.
http://www.abload.de/img/img_0002v7f.jpg
http://www.abload.de/img/img_0046t8f.jpg
http://www.abload.de/img/img_0030ur1.jpg
http://www.abload.de/img/img_0104qqi.jpg
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Old May 8, 2008, 11:57 AM   #2
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That looks typical of what I'd expect to my eyes. The first image looks fine from a sharpness perspective (where the subjects sitting on the bank on the right side of the image is concerned, with the rest of the image acceptably sharp (and I see f/13 was used). You do see some DR (Dynamic Range) issues from the harsher lighting (to be expected)

In the next image, the brush you're focused on is so close, you're going to have a very shallow depth of field (and the camera was using f/8 ), and that looks like what I'd expect focusing on something that close).

In the next image, that looks like you were using an external non-dedicated flash from the reflection in the sunglasses (or, that's just sun coming from behind you). That's about what I'd expect in harsher lighting, although it's a tad hot (slightly overexposed face). That's probably a tone curve issue and using different settings with lower contrast might help out, as the sky doesn't look blown.

The next image is slightly overexposed, and CA is a bit excessive in high contrast areas. You can see this same kind of thing in the Canon XSi review here (check out the playground image in the review samples and you'll see purple fringing).

I think that's just lens quality more than anything else, probably made worse from internal lens reflections from flare, as flare resistance seems to be a weak area with this lens from tests I've seen, even though it tends to look good on lens tests in lab conditions. The way the lens interacts with the camera's sensor also comes into play, as you can run into microlens related fringing, too.

IOW, it's probably working fine. Keep in mind that you appeared to be shooting in very harsh lighting. That's tough on any camera and lens. A better bet is to shoot early in the morning or late in the afternoon, and avoid harsher lighting conditions like that with lots of direct sunlight on your subjects for best results.

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Old May 8, 2008, 12:37 PM   #3
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Wow JimC. First I want to thank you for taking time to respond.

Second, it was in certainly was a verry bright and sunny day (seen also in pic 3 where the glasses reflect the sun).

In the second picture, not sure what the "brush you're focused on is so close" is; is it the bush right by the flowing water? I did however understand the f/8 part (from my reading and youtube video tutorials), and that makes sense I might've "accidently" locked on to the bush and shot the picture that way.

I guess i'll have to do a bit more testing to make sure. I'm sure the camera is going to get better as we see some firmware updates. At least now I have a few pointers and some advice to work with Thanks again


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Old May 8, 2008, 12:44 PM   #4
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You'll need to be careful of focus point with a dSLR, as you'll have a shallower depth of field than you will with a point and shoot camera for the same subject framing and aperture setting.

Here's an online Depth of Field calcualtor you may find useful to give you a better idea of how focus distance, aperture and focal length impact Depth of Field.

http://www.dofmaster.com/dofjs.html

Just keep in mind that you have some tradeoffs involved with things like aperture settings. For example, most lenses are not quite as sharp with the aperture wide open (smallest available f/stop number), or at smaller aperture openings (higher f/stop numbers). So, you want to try and avoid settings extremes when possible.

Also, the aperture you choose will impact your shutter speeds for a given lighting and ISO speed. If you use a smaller aperture opening (represented by a higher f/stop number) in order to get more depth of field, you're going to need slower shutter speeds to expose the image for a given lighting and ISO speed. So, you have to keep shutter speeds in mind, too (if you don't want blurry photos from camera shake or subject movement).


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