Digital noise at high ISO — put your camera through it’s paces

When you research buy­ing a dig­i­tal SLR cam­era we all read about what it can do. So when you finally get the cam­era of your choice and you pull it out of the box, now is the time to see what it cant do. One of these tests that you should per­form is a high iso test. What we are look­ing for in a test like this is to see at what point in our cam­eras iso range does the image itself become unus­able for your final pur­pose. Be it either online pre­sen­ta­tion, fine art print­ing, com­mer­cial print­ing etc.

Before we go any fur­ther lets have a look at how to set up to test your cam­eras iso range and the results of a test done on the Canon 5D Mk II in low light.

Set­ting up your cam­era:
If your cam­era has the option acti­vate the ISO expan­sion set­ting. (You may want to check your user man­ual for this). This will allow your cam­era to go to it’s fullest iso range in both low and high ISO. Also make sure your cam­era is set to cap­ture RAW files. RAW + jpeg is fine as long as you have RAW files to look at.

Per­form­ing the test.
1. Set your cam­era on it’s low­est ISO set­ting. For the Canon this could be 50 or 100, for Nikon users this will be L1.0 (100 iso).

2. Tri­pod mount your camera.

3. Obtain your best expo­sure at an f-stop (aper­ture) of your choice. Now with those cap­ture set­tings dial that into your cam­era on man­ual. This will give you con­sis­tent look­ing expo­sures in the images.

4. Take a shot with your hand in front of the cam­era (or some­thing), we will do this again at the end of the test. As this will let us know that the ISO test is in between these two shots.
Very help­ful when you have a card full of images.

5. From your 50 ISO and fixed shut­ter speed. (Lets say it is 1/30 sec) take a shot and then increase both the shut­ter speed and ISO one stop. So now you would have 100 ISO @ 1/60 sec. Now repeate this process until you reach your cam­eras max iso.

6. Now in your RAW image edit­ing soft­ware open up all your ISO test files together. View them at 50% and look at the qual­ity of the pixel noise in each. There will be a change between two images where you find it accept­able and un acceptable.

The image with the accept­able ISO noise before it is unac­cept­able, is now the max­i­mum ISO that you want to push your cam­era too.

In my ISO test with the Canon 5D MkII I found the ISO change between 3200 and 6400 to be the deal breaker. 3200 ISO being what I wouldn’t want to push my cam­era past for the image qual­ity I am look­ing for in my work.

My test as you can see was done in a lower light sit­u­a­tion, over­cast day under the canopy of trees, but there is no rea­son why you cant do your test or test in dif­fer­ent sit­u­a­tions. It is all about exper­i­men­ta­tion and under­stand­ing your cam­era. Sure you can read about the results in a mag­a­zine or on a web­site but do it your­self and see first hand the qual­ity difference.

Some quick gen­eral info:

Nikon ISO is stated dif­fer­ently than Canon for some rea­son in it’s lower ISO range. You will see your ISO go from 200 to L1.0, L.07 and L.03. These set­tings are L1.0 = 100 iso, L.07 = 125 iso and L.03 = 160 iso. So basi­cally 1/3rd stop incre­ments from 200 iso to 100 iso.

Matt Lauder is the edi­tor of the Rub­bing Pix­els web­site and is a full time land­scape pho­tog­ra­pher based on the Cen­tral Coast of NSW. To view Matt’s full pro­file and the range of video he has con­tributed to the site please click here.