Why Are My Photos Noisy?

Grainy photos have a speckled appearance to them. This is different than photos that have a blocky appearance, which have a different cause. See the next section below about what causes blocky looking photos.

Noise is caused by setting the ISO to a high number. The ISO determines how sensitive the sensor is to light. A high ISO, such as 1600, makes the sensor more sensitive to light. It will allow you to take photos in dim conditions. The disadvantage is that it creates more noise.

The noise created by digital cameras has a speckled appearance. Sometimes the noise is created by variations in value. One pixel may be slighter darker than the pixel next to it. There’s also noise that is created by slight differences in color.

One way to prevent noise in your photos is to shoot with the ISO set to a lower setting. I recommend using 100 to 400. Of course, this depends upon the camera that you’re using. DSLRs tend to have less noise than smaller point and shoots.

The actual, physical size of the sensor has an influence on the noise in your photos. The smaller sensors in compact cameras create more noise. It’s also important to note that the size of the sensor is different than the resolution. For instance, a point and shoot and a DSLR may both have 18 megapixels but the sensor in the DSLR has larger physical dimensions. A sensor from a compact camera may measure 7.44mm x 5.58mm while a DSLR sensor measures 22.3mm x 14.9mm.

Avoid the auto ISO setting because the camera will change the setting based upon the brightness of the subject. This may lead to having some photos that are noisier than others.

“Trees at Krull Park” watercolor and ink on paper. Chris Breier © 2018
This photo is from my Canon DSLR. It’s a close up of a branch in the watercolor painting above. The top half was taken at ISO 6400 and the bottom half at ISO 100. There’s more noise in the top half, especially in the dark areas.
This is from my Canon s95 compact camera. The top half was taken ISO 3200 and the bottom at ISO 100. The higher ISO creates more noise

Why Do My Photos Look Blocky?

Blocky photos have a pattern of large blocks in them. This is different than noise which creates a pattern of fine speckles in the photo. There are three possible causes for photos that have a blocky appearance.

  • Low resolution setting
  • Using the digital zoom function
  • Setting the jpeg compression to the lowest quality

Low Resolution

If you set your camera to the lowest resolution, the photographs may have a blocky appearance. These blocks that you see are the actual pixels that the image is made up from.

The red inset is an extreme enlargement that shows the grid of pixels that the photo is made up of. The photograph is of the Niagara River.

Digital photographs are made up of a grid of squares. Each square is assigned a color. When you take a picture with a low resolution, then this grid becomes more visible to the eye. Details are lost and the photo has an overall “chunky” or “blocky” appearance.

The solution to this problem is to set your camera to the highest resolution setting. Check your manual if you don’t know where to change the resolution settings.

It’s also possible to lower the resolution when you edit a photograph in Photoshop. If you use the “save for web” feature it allows you to change the resolution when exporting to a jpg. Pay attention to this setting when you export your photos.

Turn Off the Digital Zoom Function

The “digital zoom” feature on many compact cameras is a gimmick that you should avoid using. Refer to your camera manual for instructions on how to disable it. DSLRs don’t have this feature, although some have a crop feature which produces similar results.

The digital zoom makes it seem as though you can zoom beyond the limits of the lens but it’s a trick. What it’s actually doing is cropping the photo which creates the illusion of being able to zoom in further. In other words, it crops the photo to a smaller section of the image and then enlarges it to fill up the frame–without adding more detail.

This is the same as cropping it with photo editing software.

Most cameras with this feature have an indicator on the LCD that lets you know if you zoomed into the “digital zoom” range. Another indication is if you don’t hear or see the lens extending but the image is enlarging on the screen as you zoom.

The “digital zoom” function crops in a section of the image, such as the area with the Red box, and then and enlarges it. It has the same effect as cropping a photo in photo editing software. The photograph is of trees at Chestnut Ridge Park.

JPEG Compression

The JPEG compression settings have an impact upon the file size. Compression settings have names like “Fine” or “Normal”. It’s different than the resolution of the image.

The purpose of compression is to reduce the size of the file. It does reduce the file size but it comes with a cost to the quality. A little bit of compression is barely noticeable but aggressive compression will create a distracting blocky pattern within the image.

Set the compression setting to the highest quality. The files will be larger but this is important if you plan on making prints from your photographs. If you’re saving a jpg to share online, then you can go ahead and increase the compression to create a smaller file size.

The compression algorithms are complex but the general idea is that it reduces the amount of similar colors in a photo.

You may have noticed that the size of the jpg varies depending upon the subject. A photo of a White wall will have a smaller file size than a photograph of a group of colorful flowers that contains a variety of colors and a lot of detail. The compression works to reduce the amount of colors in a photo to create a smaller file size.

This close up is from my Canon s95 with the resolution set to the lowest setting with the greatest amount of compression. It has numerous compression artifacts which you can see around the branches of the trees.

How Do I Align the Painting in the Viewfinder?

It happens to all of us. You take the picture and you don’t notice it’s slanting to one side until you view it in Photoshop.

One principle that I like to follow is to “get it right in the camera.” This means make all of the corrections when your taking the photo instead of relying on fixing it in Photoshop. Take the time to review the photo on the LCD before moving on to taking the next photo. Straightening a photo in the viewfinder is rather simple. The adjustments on the tripod will allow you to tilt the camera left or right.

Compare the edges of the painting to the edges of the LCD. If they’re not parallel then you need to make some adjustments.

A copystand allows you to photograph the painting while it’s laying on the base of the stand. In this case you can just nudge the painting to align it.

How to Straighten a Painting in Photoshop

If you notice a painting is crooked when you’re viewing it on your computer then you can straighten it in Photoshop. This is faster than having to set everything up and shooting it again. There’s also no guarantee that you’ll get it perfectly straight the second time around.

I explain in detail how to straighten a painting in Photoshop in a separate post. I’ve been using Photoshop for a long time and I have to say this is the fastest and easiest way to straighten an image. If you fumble around with trying to manually rotate a photo, then you’ll want to read this because it will save you a lot of time.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *