Grainy Photos - Need advice

[MarkH]

Hiya all i'm new to photography and new to these forums so I'm hoping you guys can help me.

I recently went on a trip to London and noticed when back home a lot of my photos are rather grainy. I have attached links below to show you a sample of what I mean. The photos were taken on my Canon 450D with the standard Lens Kit. As I say I am new to photography the most I have used in the past is a compact camera on Automatic with this I did a little reading set the camera on RAW and used the Live View to help me choose the right settings.

Anyway here are a couple of images if you could take a look and advise me why they appear so grainy id be greatful. I know having a high ISO can cause Noise so I made sure this was low (100-200) in the light pictures.

(Sorry the images are around 10mb each so you can see the grain)

http://cloudbite.co.uk/photos/image1.jpg
http://cloudbite.co.uk/photos/image2.jpg
http://cloudbite.co.uk/photos/image3.jpg

Cheers,
Mark

 

[subscuck]

I only looked at the first pic, but the ISO is 800, not 100-200. Were you shooting in Auto? If so, no matter where you set the ISO in the menu, the camera will still set it where it chooses. The only way you have control is in the semi-auto modes.

 

[Robin Usagani]

and used the Live View to help me choose the right settings.
Cheers,
Mark

So you look at the screen and if it looks like the right exposure, you shoot? Are you sure it didnt change the ISO?

 

[KmH]

In digital images it's called 'noise' instead of grain.

The last photo also list it at ISO 800, so it looks like it was user error.

Plus being it's a scene having a significant amount of direct sunlight, the 1/800 shutter speed at an f/10 aperture should have been a clue you weren't at ISO 100 or 200, which would have resulted in a shutter speed 2 or 3 stops slower.

 

[Steve01]

As already stated, ISO 800 is the problem.
Use the lowest ISO setting you need to get the shot right.

 

[MarkH]

Hiya guys, thanks so much for your replies, I think I must of accidentally been changing the ISO as you say its on 800. I didnt realise the file saved all that data otherwise probably would of seen for my self. But thanks for the replies it was really bugging me. In sunlight ill make sure I keep an eye on keeping the ISO low. I don't really want to use the auto setting as 1 it doesnt let you shoot in RAW and 2. I would rather learn how to use the camera and make these mistakes.

Just a quick question the "F stop" I believe its called I think I read that determines wether the background is in focus or not (this is probably wrong) but if not why is it changing how dark the photo is I find I am putting usually really high or low. Obviously I need to do more reading but if you have a quick easy way of knowing the basics would love to hear (read) them!

Cheers Again!
Mark

 

[KmH]

The f-stop is the size of the aperture in the lens. It is one of the things that controls how much light gets to the shutter and has a large bearing on how long the shutter needs to be opened for, to let the light impinge on the image sensor.

Another consideration of the lens aperture is how much depth-of-field (DOF) it gives.



DOF is actually a function of 4 variables:

1. the lens aperture (f-stop)
2. the lens focal length
3. the subject to image sensor distance
4. the subject to background distance, if any.

Back to the f-stop idea.

Most cameras today default to 1/3 stop adjustments, but it is critical to understand what a full stop is.

A full stop either lets in twice as much (larger aperture), or half as much (smaller aperture) light. To let in twice as much light the diameter of the aperture must be increased by the √2, the square root of 2 (1.414) so the area of the opening is doubled. To halve the amount of light the lens aperture diameter must be reduced by the √2.

Full stop apertures:

f/1
f/1.4
f/2
f/2.8
f/4
f/5.6
f/8
f/11
f/16
f/22
f/32

 

[dak1b]

isp is ur issue, stated above.

try lower iso settings such as 100-400 at most during day

 

[Steve01]

Just a quick question the "F stop" I believe its called I think I read that determines wether the background is in focus or not (this is probably wrong) but if not why is it changing how dark the photo is I find I am putting usually really high or low. Obviously I need to do more reading but if you have a quick easy way of knowing the basics would love to hear (read) them!

Cheers Again!
Mark

The "F stop" refers to the aperture setting.
The aperture is an iris in the lens that closes down very small (high f#- f22, f32, etc.) or opens up very wide (low f# - f1.4, f1.8, etc.)

Each time you adjust the aperture up or down one full stop, you double or halve the amount of light getting into the camera.

Don't think about aperture settings as

"determines whether the background is in focus or not".

It's called depth of field and it really means what's in focus in front of and in back of the thing you focused on.

The larger the aperture, the narrower the things in focus will be in front and behind the subject.
The smaller the aperture, the deeper the things in focus will be in front and behind the subject.

By changing the aperture you're not changing how light or dark an image is because for every change in aperture you should be making a change in shutter speed, compensating for the aperture adjustment.

The simplest way to accomplish all this automatically is to shoot in Aperture priority mode.

There's a lot more to it than that but I hope this clarifies it a little for you.
Steve

 

[MarkH]

@KmH and Steve thanks so much for your explanations they have really helped. When I was adjusting the F stop I was finding I did need to adjust the shutter and now know this is right as I thought I was doing it all wrong.

You two and everyone else in the thread have helped me a lot and I am really grateful! I'll definitely be sticking around in this beginners forum having a read what others come across and the solutions. Now all I need is a nice day to go out taking some snaps and put what you guys have told me into practise.

Thanks Again
Mark

 

[Rajeen Loius]

Its really nice shots nonetheless, I hope the advice helped!

 

[Polyphony]

How did you guys get the photo info from those images?

 

[KmH]

How did you guys get the photo info from those images?

By using an EXIF data reader. Exchangeable image file format - Wikipedia, the free encyclopedia and right clicking on an image.

There are free EXIF readers available for download:

www.opanda.com
www.photome.de PhotoMe is an EXIF editor and can also write EXIF data.

 

[KmH]

How did you guys get the photo info from those images?

By using an EXIF data reader: Exchangeable image file format - Wikipedia, the free encyclopedia and right clicking on a photo. Editing a photo often strips the EXIF data.

www.opanda.com (EXIF reader)
www.photome.de (EXIF editor)

 

[Polyphony]

How did you guys get the photo info from those images?

By using an EXIF data reader: Exchangeable image file format - Wikipedia, the free encyclopedia and right clicking on a photo. Editing a photo often strips the EXIF data.

www.opanda.com (EXIF reader)
www.photome.de (EXIF editor)

Thanks