I thought I would post a compilation of 4 images showing the results from 4 different lenses. I've left the Nikon 28 f2.8 out because of the poor performance of the lens. I'll repeat here that the poor performance was due to a bad copy of this lens, and if you should purchase a good copy the performance should be up there with the best. My 50, 100 and 135 E Series Nikon lenses perform very well indeed on the Nex and m4/3 cameras.
Opening the image to full size it's easily visible that the Pentax Takumar (top right) has the best rendition and sharpness of all the lenses. The colour is also better to my eye but this is easily corrected in post.
The Olympus OM 28 f2.8 came in second (top left). These 2 images were taken just seconds apart.
The bottom 2 images taken with the Sigma and Vivitar lenses were taken several days later so the lighting is a little different. Both don't come close to the Takumar. They do however, look so similar that I would have said the lens is from the same manufacturer, but I don't believe this to be the case. Why? I'll post the reason tomorrow.
This will be the last single image from my 28mm f2.8 lens testing. If you're wondering which lens I rate the best in this focal range then it's the Pentax M Takumar 28 f2.8. Remember, I still have two more lenses to test, a Canon 28 f2.8 and a Konica 28 f3.5. If they are to surpass the Pentax then they will have to be very good indeed.
The Pentax is superb in every sense, use, build, rendition. These old Takumar lenses (all of them) are among the best lenses ever built and if you haven't tried one, you should. An all metal build, the focusing ring is very smooth and when you change the aperture it actually feels like you've changed aperture. It clicks nicely into place and won't budge until I decide to change it again (unlike the Nikon 28mm I tested). Everything felt right with this lens and is real fun to use. After I have tested my two remaining lenses I will repost about which lens will have a permanent place in my 28mm arsenal.
I know I've said that these lenses perform well on the Nex bodies (APS-C sensor) I much prefer the image quality I get from my m4/3 bodies. The sensor is smaller so you're effectively using the best part of the image and the corners tend to be cropped out at the time you take the shot. So you may be asking why I keep on using the Nex bodies, well it's simply because of the focus peaking function. With focus peaking creeping into the m4/3 bodies nowadays, it might be that I'll be switching shortly permanently to those cameras. But that remains to be seen.
If you have any questions about these lenses or if you want anything tested, just mail me or leave a comment and I'll see what I can do.
How do you determine when to keep a lens or not? Well, for me personally, a lens has to feel good in the hand and is nice to use. If it doesn't have that then I'll probably not use it much simply for the fact it's not fun to do so. Not being a professional at this I can pick and chose as I like.
If a lens has that effect on my then I'll look at the image quality, how the lens renders on the sensor. If, of course, image qualiy is then abysmal I'll either try with a second copy or not use the lens at all. The final image is the whole point of this photography thing after all, and that is very important but I also like to use the tools I have to get to the final product.
I look at the image above and remember thinking at the time i took the shot that it would be for me, a pleasing image to look at. I could tell at the time that the lens had produced what I was after and if you enjoy using your tools you will, I guarantee, be more careful with your image composition, focusing and everything else that comes with it.
As expected from Olympus,the quality and feel of these OM lenses is just superb. I also own the 50 f1.8, 100 f2.8, 135 f3.5 and the 135 f2.8 OM lenses and they all perform really well on the Nex cameras.
I expected this lens to be top of the 28mm list but it actually came in second. After posting some images from this lens I will post a composit from 4 28mm lenses where it's possible to see the differences between the lenses, even at the size that my images are posted.
As you can see from my images from the 28mm lenses I attempted to take the same scene or as near as I could with each lens, I had to have some reference points to look at the image quality from each lens (i.e. How the lens renders on the Sony body). It's only when you do this with a few lenses you come to realise the subtle differences between each lens and manufacturer.
The second example from the Nikon 28 f2.8, just to show what to expect from a lens of this vintage. Just as a reminder, my copy of the lens wasn't stellar so expect better from a lens in pristine condition.
I had high hopes for this lens as my Nikon 50 f1.8 and the 100 f2.8 are very sharp and are a dream to use in the field. However, this is the worst 28mm lens I have used to date. There's a lot of play in the focusing ring and the aperture ring must have some wear to it as it moves too easily. Every time I took it out of my bag I had to recheck the settings which proved necessary. It seems to be decentered as the left side is pretty soft and the right side could be sharper as well. All this makes me believe I bought, not a bad copy, but certainly one not in pristine condition. After using my 50 f2.8 and 100 f2.8 from Nikon, the 28mm can't be this much worse. Built quality is great, and if I has received a better example then I believe this lens could have been up there with the best of them. I didn't receive a great example so I have to live with it.
I don't think I'll be purchasing a second copy of this lens as I have several good to great 28mm lenses already. However, I will post a couple of images from it just to show what it's capable of. A better example can produce better images obviously but the posted images are considered good enough for web use.
The is the only image I'll be posting from the Vivitar 28 f2.8 which turned out to be a surprise because if I remember correctly postage was dearer than the lens itself. You don't find those too often.
Again it has a metal mount and handles very nicely. Images are pretty low in contrast, as the Sigma 28 f2.8, but they prove to be very processable in LR and Photoshop. As you can see in the image above, the end results are presentable, but that's it.
Having said that, it wasn't the best lens I tested and this will not be staying in my collection.
The same applies to the above image, the more I look at it the more I like it. That doesn't mean there wasn't a lot done in post to get it to look like it is above.
This is the last image from the Sigma 28 f2.8 for the present but I will be coming back to it in my conclusions for the 28mm lenses.
To be honest, if I leave images that I've processed and come back to them after a couple of weeks, I get a completely different feel for the images. The same has happened to these images from the Sigma 28 f2.8. They look better and better the more I look at them now. After I'd processed tham I really didn't think much about the image quality, but when looking again at the above image I quite like it.
This is a lens that I haven't seen too often in shops or offered on ebay (in Germany anyway) but it's turned out to be an ok lens. It handles nicely and the focusing ring is nicely damped. It has a metal mount and the lens is quite hefty when on the Nex-5N.
Images lack contrast and like all Sigma lenses that I've tried (including their modern lenses) has a slight yellow tint to them. Easily corrected in post of course but it's still an extra step to go through. They sharpen nicely in post and the finished images don't look too bad. It's quite probable that quality variation can be expected when purchasing these lenses so make sure you test it thoroughly.
The image above is typical of my minimalistic phases I get from time to time. The metal barrier was quite close and as you can see the lens did quite well at close focusing distances.