Last month during my wedding, I found that my 18-70mm zoom lens was really quite useless for low light indoor shots. Note: I have no complaint with its outdoors capabilities. I also discovered that the standard flash that comes with the D50 sucks - it either overbrightens the image - makes everyone look white as ghosts or it fails to go far out enough to illuminate at a distance.
To rectify this I bought a faster lens (i.e. bigger aperture) - Nikon 50mm F1.8D. I also bought an external zoom - nikon SB 600 (to be tested by me soon).
Note: for all the shots below, there was no post processing in Photoshop apart from reducing the image size by 50% and applying very minimal unsharp mask (0.2%). WYSIWYG. No fancy curves, colors, levels, higher sharpness tricks
Here's some close-up shots to evaluate the new len's sharpness and bokeh capabilities. I was focussing on the top most flower from a distance of about 8 feet.
F1.8 -> F2.2 -> F2.5 -> F3.2 -> F7.1 -> F8 -> F11
Analysis: The lens is fantastic wide open at F1.8 all the way to F11.
I was curious to see how the F1.8 lens compared with my 70-200mm lens. It (along with 200-400mm lens) is widely regarded as perhaps the best quality Nikon zoom with quality equivalent to the best prime lenses. The 18-70 is what you would call a decent lens - not crap and not fantastic either.
To avoid getting carpal tunnel typing the big ass names, I will assign them letters.
50mm F1.8 D Prime = A (costs approximately $105)
70-200mm F2.8 zoom = B (costs approximately $1600)
Bokeh/sharpness comparo
[email protected]/50mm
--> No comparison possible as no other lens opens this wide.
[email protected]/50mm v/s
[email protected]/70mm
Both are quite sharp. The bokeh seems more pronounced on the 50mm lens (the yellow flower on the right is blurrier). The 50mm lens is now in its sweet spot as it is 2.5 stops from its max while the F2.8 lens is at its (relatively speaking) weakest as it is wide open.
Portrait capability
A: Wide open/ F2 /F2.8 / F8 all at 50mm
B: Wide open F2.8/F3.5/F8 at ~200mm
Both lenses are pin sharp one stop beyond max aperture. Lens B gives sharper images but its bokeh is in some ways superior to Lens A: it is creamier.
Enough of playing around outside. I moved inside to test low light capabilities.
I went up my staircase and took shots focussing on Senna's helmet on the banister.
First A vs C:
A @ 50mm/F1.8 vs C@70mm/F2.8
The 70-200mm lens' VR (vibration reduction) feature was on to help it. I wanted to see whether it could compensate for the 1.5 times smaller aperture compared to te 50mm lens
The Senna helmet is sharper in the F1.8 lens - see the Nacional sticker.
For grins, I ran the 18-70mm lens at 50mm/F4.5 and got this blurry image
F1.8 vs F2.8 vs F4.5 may not seem very different but take a look at the shutter speed to understand the difference: it takes 0.08 sec for taking a picture at F1.8 aperture versus 0.25 secs at F2.8 and 0.5 sec at F4.5 lens. At F8, you need 1 second to take a picture. So put yourself in the situation where you are at an art gallery and are not allowed to use the flash, isn't it a lot easier to hold you hand still for 0.08 seconds compared to 0.5-1 second for poorer lenses. That's the beauty of big aperture lenses.
This is the reason why I wanted a new lens. Indoor shots are crap with the 18-70 lens - requires the flash all the time.
Overall, I am very satisfied with the performance of the new lens. The only negative (albeit minor) is a relatively slow and noisy focus compared to the lightning quick 70-200mm lens. Also, obviously due to its fixed zoom @50mm, you will need to walk about more to compose your shots compared to a true zoom lens which does the walking for you.
The price makes it a must have purchase for every Nikon DSLR owner. I think I now have lenses for all occasions:
18-70mm: Walk-around/Outdoors only/Wideangle
50mm: Close-up/Portraits/Indoors/limited Walk-around/outdoors
70-200mm: Racetrack/portraits/Close-ups
Alternatives to 50mm? You can get the 50mm F1.4 which give about an extra half a stop of light. But it costs ~$260 - nearly 2.5 times the price of this lens. You can get a 85mm/F1.8 but this costs $350. The F1.4 version of this lens is one the finest lenses Nikon makes - used used by professional portrait photogs or tennis, basketball photogs. costs $1000 -gulp-
Ideally what I could do with is a 35mm F1.8D which would be ideal with the 1.5 crop factor with most of the Nikon DSLRs. The 50mm is a bit too much zoom built into it. But hey, you can't have everything.