I have four lenses that cover the same focal length of 45mm ( Why four ? Interesting question but the good thing my wife doesn’t read my blog! And the people who read this blog most likely have similar lenses).

Update  12/18/16 : Still learning how Wordpress formats images, so added the screen capture again for 100% view

1. Olympus 40-150mm f/4 to f/5.6 $100
2. Olympus 12-50mm f/3.5 to f/6.3 $200
3. Olympus 45mm f/1.8 $299
4. Panasonic 35-100mm f/2.8 $899

Though each lens is for different purpose, I wanted to test if it’s worth carrying all thelenses and more importantly is it even worth changing the lens just for image quality.   Camera tested OM-D E-M5, (Waiting to get E-M1 Mark II) so I will do an update after getting the new camera.

ISO 200 45mm & 35-100 f/2.8

The light was barely enough for handheld shot at ISO200. With other lenses it was not possible to get hand held shot at ISO 200.

Sharpness:

Left : 35-100mm f/2.8                                           Right : 45mm f/1.8

The difference is barely visible, but obviously the prime is sharper only when viewed at 100% as noticed on certain  “No Diving Allowed” letters.  Unless I am planning to print, it’s not worth changing the lens for f/2.8 and above.

Color and Contrast:

Identical,  maybe I slightly prefer Panasonic rendering.

ISO 500

The difference is very stark. I don’t even need to zoom 100%, just looking at the preview the difference was very obvious…12-50mm is not good at 45mm.

The prime f/1.8 and the f/2.8 zoom are close at f/5.6. The prime lens captured red little bit better.

35-100mm f/1.8                     12-50mm                            45mm

 

When looking at the people in the picture, 12-50mm lens makes the face very blurry. But the prime and the expensive panasonic lens were similar and produced cleaner results.

ISO 1250

I tried the same at ISO1250, with speed of 1/100th of second to avoid any handshake, the difference is much more apparent between 12-50mm and other lenses. Still panasonic lens is closely matched to the prime lens.

 

ISO 1600:

Top Left : 40-150mm @f/6.3                                 T0p Right :  12-50mm @ f/6.2

Bottom Left : Panasonic 12-35mm @f/6.3          Bottom Right:    Olympus 45mm @ f/6.3

The results very obvious, I don’t even need to look at the meta data. The ranking is very clear:

1. Olympus 45mm f/1.8 prime and close
2. Panasonic 35-100mm f/2.8
3. Olympus 40-150mm f/4 – f/5.6 and a distant
4. Olympus 12-50mm  f/3.5 – f/6.3

12-50mm is not bad lens, but looks it should be avoided in the tele-zoom range.

Here are all the photos shown above..

Which lens to swap at 45mm (90mm equivalent) :

45mm f/1.8

While shooting portraits, to get  the equivalent DoF of  45mm f/1.8 I have to use 70mm f/2.8 with 35-100mm lens.  Which means moving further back and not at a comfortable talking distance. The full frame equivalent is like choice between 85mm lens at f/3.5 or 135mm lens at f/5.4.

Or when the light is ver low and the extra stop of aperture is keeping from moving above ISO3200.

35-100m f/2.8

Everything else, no need to swap to prime for the sharpness.

40-150mm f/4 to f/5.6

When the light is decent enough, very good at the lower end of the zoom

12-50mm f/3.5 to f/6.3

Should be avoided at longer end of the zoom. Should be used just as wide angle zoom

Summary

I started this topic to compare the sharpness of the lens, but looks like the ISO performance of the lens is lot more apparent than that of the camera. So, for the same camera at the same aperture, ISO1600 of one lens is better than ISO500 of the other lens.

Even at the same aperture, the out put IQ  of the lenses are quite different. The difference isn’t obvious at low ISO, but quite obvious in a high ISO. Though I have posted the images of brick and flag, for the faces at the same lighting condition, the image ranges from being blurry even for  screen view to sharp enough for printing.

This helps me understand why my results with the high ISO D810 (link to review) , are quite different from most of the reviews. The reviews of the camera generally use the best lens available for that camera, and the lens reviews typically test the sharpness at different aperture at the lowest ISO in best camera.

So quite happy with the purchase of f/2.8 zoom lens,  wish Olympus has brought their f/2 zooms in the m4/3 system.