What digital SLR camera lens is equivalent to the 35-80mm lens on film SLRs?
January 6, 2009 by Cam
Ali asked:
I am looking for a lens for my Olympus E300 that has the equivalent focal length of my regular SLR's 35-80mm lens.
I am looking for a lens for my Olympus E300 that has the equivalent focal length of my regular SLR's 35-80mm lens.
That depends entirely on the size of the IMAGE SENSOR and can vary from one manufacturer to another. The easiest way to determine this is to find out what the “crop factor” value is for the model of the camera you want to use. For example a crop factor of 1 would mean that the sensor is exactly the same size as a full frame 35mm camera and the lens would be exactly the same.
For a camera with a 1.5x crop factor the lens would be 34/1.5 or 24mm (rounded up) to 80/1.5 or 54mm so a 1.5x crop factor would need a 24-54mm range.
For a camera with a 2x crop factor it would be 34/2 or 17mm to 80/2 or 40mm so the lens would be 17-40mm.
Smaller sensors allow better power management, smaller & lighter camera and lens construction and improved optical designs for lenses to be used with sensors (for design reasons image sensors need more direct or “straighter” light paths than film). The sensors also generate less heat which may cause image deterioration when a camera is used continuously.
The advantage of larger sensors is that they can have physically larger “pixels” so they are less likely to have a bleed over from adjacent pixels. The bleed causes image deterioration in the form of “noise”.
Typical crop factors are in the range from 1.3 – 2.0. Most camera companies use whatever they want but some cameras have adopted a standard called Four/Thirds which has a 2x crop factor.
Hope this helps.
Email if you have more specific questions.
EDIT: Additional info, the Olympus 14-45 “kit” lens is roughly equivalent to a 28-90mm and would be very comparable. I have a lightly used one for sale. If you are interested contact me via email.
Your sensor is half the size of a full frame sensor, so your multiplication factor is 2x (that should be in your cameras manual)
Rob Nock is right, “For a camera with a 2x crop factor it would be 34/2 or 17mm to 80/2 or 40mm so the lens would be 17-40mm.)