Canon 400D - Blurred images

[thegcstoat]

Hi all,

In late 2007 I purchased a Canon 400D camera outfit which included a Canon 18-55mm lens. I also purchased a Sigma 10-20mm and 55-250mm lens as well.

When using the 18-55mm lens that was bundled with the camera, I often get blurring of the images - particularly when using the built in flash. I generally shoot inside using 'TV' or 'P' mode, an ISO or 400 or 800 and with some flash compensation to brighten the images slightly. The shutter speed is normally no slower than 1/60th.

I also have a larger, detachable flash which gives excellent results but it's not always practical or convenient (or sometimes I simply haven't charged the batteries!) to use.

Before buying the camera, I checked the reviews. The camera generally got a thumbs up but the lens generally got a thumbs down. Could it be the lens causing this blurring problem? Or simply the way I'm taking photos?

Many thanks for any feedback.

Matt.

[PhilW]

post some examples

[thegcstoat]

A couple of points I forgot to mention:

Quite often, the photos tend to be in focus at a depth behind the subject. Originally the camera was set to automatic AF Point (or multipoint focus). Very early on I set the camera to single point AF (the centre point most of the time) and ensured that this point was always over the subject.

Here's a cropped image showing a typical example of the problem:



Moderators Note: You need file extension at the end (.jpg) to display the photo.

[Malcolm_Stewart]

Hi all,...

...Before buying the camera, I checked the reviews. The camera generally got a thumbs up but the lens generally got a thumbs down. Could it be the lens causing this blurring problem? Or simply the way I'm taking photos?

Many thanks for any feedback.

Matt.

I suggest you do a simple check on your kit lens. Set your camera to M mode, a shutter speed of 1/125 and an aperture of f8, and an ISO of 200. Using the built-in flash take a few snaps of fairly close objects in your home (say 4'-7') in the evening with normal domestic lighting, and examine them for sharpness. By using M mode, you're in control, and the camera should ensure that it's the very short flash exposure that's the main contributor to the exposure.
I've now seen your example - do use the centre AF focus spot for the test, and use OneShot mode.

I also have the kit lens, and with care it is possible to get sharp results with my copy. If your kit lens is adequately sharp in this test, get back to us for further suggestions. When you do, please supply the EXIF exposure info for the blurred shots.

Edited after seeing example snap

[thegcstoat]

Many thanks for the replies. I was meant to post the Exif info with the photo but had trouble uploading the photo itself and completely forgot! Anyway, here's the data:

Apature F4
Exp 1/60
ISO 400
Focal 25mm

If you need anymore info, let me know. I'll get those photos taken this evening.

Many thanks again,

Matt.

[El_Sid]

Anyway, here's the data:

Apature F4
Exp 1/60
ISO 400
Focal 25mm

Hmm, f4 at 25mm on the kit lens is, I suspect, pretty near wide open... This may well be at least part of the problem as this lens, even on the best copies, really needs to be stopped down 1 or 2 stops to get the best performance. It's a lens pretty much known to be soft at maximum aperture.

[Benchista]

Anyway, here's the data:

Apature F4
Exp 1/60
ISO 400
Focal 25mm

Hmm, f4 at 25mm on the kit lens is, I suspect, pretty near wide open... This may well be at least part of the problem as this lens, even on the best copies, really needs to be stopped down 1 or 2 stops to get the best performance. It's a lens pretty much known to be soft at maximum aperture.

Oh come on, Nigel, the lens isn't that soft.

The subject doesn't appear to be in focus. Hard to tell from this crop, but I think the only thing that might be in focus is the metal strip at the back. If you post the full image, though, it's easier to tell.

[thegcstoat]

Here's the full image. Although the subject isn't exactly centre in the picture, I ensured that the focus was locked to the subject before taking photo.

Click here for photo

Mod note: Please see here for a guide to posting images on the forum thanks.

[Benchista]

Hmmm, well the point of focus is most certainly well behind the subject. Silly questions firt, I'm afraid - are you sure you were in one-shot focus mode and not continuous AF?

[thegcstoat]

Yes, the camera was in one shot mode not continuous.

[thegcstoat]

I suggest you do a simple check on your kit lens. Set your camera to M mode, a shutter speed of 1/125 and an aperture of f8, and an ISO of 200. Using the built-in flash take a few snaps of fairly close objects in your home (say 4'-7') in the evening with normal domestic lighting, and examine them for sharpness. By using M mode, you're in control, and the camera should ensure that it's the very short flash exposure that's the main contributor to the exposure.
I've now seen your example - do use the centre AF focus spot for the test, and use OneShot mode.

I also have the kit lens, and with care it is possible to get sharp results with my copy. If your kit lens is adequately sharp in this test, get back to us for further suggestions. When you do, please supply the EXIF exposure info for the blurred shots.

I set the camera to these settings and took a few pictures around the house and they came out perfect, no blurring of the subject. Is it worth just spending a bit of time in manual to get these better photos?

Here's some exif data from typically blurred pictures:

Aperture f3.5
Exposure 1/100
ISO 800
Focal 18mm

Aperture f4
Exposure 1/60
ISO 200
Focal 25mm

Aperture f4
Exposure 1/60
ISO 200
Focal 27mm

Aperture f7.1
Exposure 1/200
ISO 400
Focal 27mm


Matt.

[Malcolm_Stewart]

I set the camera to these settings and took a few pictures around the house and they came out perfect, no blurring of the subject. Is it worth just spending a bit of time in manual to get these better photos?

I suggested that you use Manual because the Canon ETTL flash system does some rather strange things when in P and Av mode, and until you're familiar with what's going on under the hood, it's not the best for fault finding. (Look for Photonotes on the web, by NK Guy for an explanation.) You say you got a sharp snap, so it seems as though your lens is behaving in a typical fashion.

The EXIF data shows that in your blurred shots, your lens was at maximum aperture, and that where it has reduced from the f3.5, that's simply because that's what it does as you zoom to a longer focal length. No (normal) lens gives of its best at full aperture, and your depth of field is also least, so in many ways you got typical results. Setting the ISO high as you did in some of them, probably allowed room lighting to register, and this too may have softened the sharpness. That's why I said use 200 ISO, for the test shot.

Here's some exif data from typically blurred pictures:

Aperture f3.5
Exposure 1/100
ISO 800
Focal 18mm

Aperture f4
Exposure 1/60
ISO 200
Focal 25mm

Aperture f4
Exposure 1/60
ISO 200
Focal 27mm

Aperture f7.1
Exposure 1/200
ISO 400
Focal 27mm


Matt.

Hope things get better from now on! Come back for more help.

[El_Sid]

Oh come on, Nigel, the lens isn't that soft.

I did say part...

[thegcstoat]

Thanks, Malcolm and everyone for feedback. I thought I was quite knowledgeable (for an amateur!) then I learn a relationship between aperture and focusing!

Just a couple of queries to finish off:

It now seems that my problem with mostly and low aperture setting and a small amount slow shutter speeds with a high ISO. Unless I set the camera to 'M' then the camera will always force the aperture low or the shutter speed low (depending on what mode I'm in) to get the required exposure. Certainly in full auto there's virtually nothing you can change. I've never been 100% happy with full auto results anyway.

So is there a way round this. Or should I just shoot in Manual?

Once again, many thanks for all the feedback!

Regards,

Matt.

[john_g]

I'd suggest that, if you're shooting things that move, then select shutter priority mode (Tv), where you set a suitable shutter speed and the camera sets the correct exposure by altering the aperture. For portraits, landscapes etc., I'd use aperture priority mode (Av), where you control the depth of field by choosing the aperture and the camera sets the correct exposure by altering the shutter speed. And always keep the ISO setting as low as you can, only increasing it where low light would otherwise prevent you from capturing a properly exposed, shake-free image.

[Malcolm_Stewart]

Most people who use Canon DSLRs recommend using M mode when using flash. This puts you in control - the only thing to watch is that you don't set a higher shutter speed than the top sync speed, which is 1/200 for your body. Exposure control in this mode when using flash is done via the Fe +/_ compensation which looks as though it's done via a Menu setting, for your 400D. +2/3s is often recommended, but do some trials.

The P and Av modes with flash are more aimed at fill-in flash in daylight, and from memory you may need to set a custom function as well. It'll be in the Manual, somewhere. For this usage you can set both flash exposure compensation, and main exposure compensation at the same time, and independently.

[Benchista]

Yup, for this sort of shot, manual works best in the world of Canon flash.

[beejaybee]

manual works best

Yup.

[PhilW]

manual works best

Yup.

Hmm, you lot are usually fairly complimentary about my use of flash...

I shoot cannon and rarley use M mode when using my flashes...

[Benchista]

I don't use it too much myself, either, but generally I'm wanting to balance flash and ambient exposure, and use aperture priority (and a tripod). If I want to control DOF with straight flash, though, it's always manual.