Originally posted by koraldon I know there might be some variance due to the manufacturing and wanted to ask what is a simple way to check that the lens quality I have is similar to other lenses ?
i.e. to photograph somthing using pre-defined setting, etc...
Do you have any other lenses with similar focal lengths? That's the best way to compare. If you only have the 18-55 you should be able to compare it to the 55-300 at 55mm. At the same aperture, the 55-300 should have better resolution. I usually shoot a cereal box to test lenses. It's a good size for testing at medium and longer distances and the print on the box shows up differences very readily. You can also use a cereal box (or anything similar) see how aperture, shutter speed & ISO affect IQ.
(I can't remember what lens I was testing here, it's posted for reference only).
I have a Tamron 70-300mm and a Pentax A*300mm to compare with my 55-300 at 300mm. A tested a couple of times because I thought my 55-300 was off, but the Tamron showed me that the Pentax zoom hasn't changed. What changed is my expectations after shooting with the prime.
To test for back-focus and front-focus, I use the chart at the bottom of the page posted below. Lay the printed chart on a flat spot that's well lit by natural light (warning, artificial light may affect focus, use daylight for testing). Set the focal length you want to test (usually the longest), use the widest aperture, hold the camera at a 45 degree angle and shoot several times to see if there is a trend to BF or FF. The directions rightly state that a tripod should be used, but I find it unnecessarily clumsy. Just make sure you have good shutter speeds and take several photos. Reset the focal length each time so the lens has to look for the target. If there is a trend, you should see it.
http://focustestchart.com/focus21.pdf