28/1.8 vs 50/1.8II

[drisley]

I almost sold my new Canon 28/1.8 USM lens last week in an attempt to buy a 50/1.4 to replace my Thrifty Fifty.
In the end I came to my senses, and decided the 28mm is a very useful focal length on the 20D. Not to mention this lens is built so beautifully.
I wasn't sure of the quality of the 28mm images, because it was a focal length I wasnt used to. You dont get the cool distortion that wide angle brings, nor the great compression and blur that a zoom brings. 28mm is basically normal length on the 20D, and what you see is what you get.
I decided to do a sharpness comparison with the much vaunted 50/1.8II.
I know the 28/1.8 is very sharp from F2.8 on up, so I chose F2.5 for the comparison.
Both images are 100% crops, taken with mirror lockup, and converted from Raw with PS CS2 and the same values. No extra processing.

I did some other testing and found the same thing... the 28/1.8 beats the 50/1.8II consistently at F2.5 and above. I also found that the 28mm has a slightly warm tone, or at least warmer than the 50/1.8II which may be slightly cool. I now think the only real drawback with the 28/1.8 is that it may be priced slightly too high.

Anyway, here are the 2 images. Again they are 100% crops that represent a good portion of the frame (the rest is mainly out of focus background).
The focus point is the letter T (which is the center focus point on the 20D), and that is also the sharpest point in both images, indicating no focus problems in either case.

28/1.8 USM (http://www.mts.net/~lftbrain/20d/28mm_f25.jpg)

50/1.8II (http://www.mts.net/~lftbrain/20d/50mm_f25.jpg)

The 50/1.8II is still one of my favourite lenses, and has never let me down. But I now have new respect for the 28/1.8 USM lens.

[tim]

The 28mm does look a good bit sharper in those tests, it makes the 50mm look out of focus. It's probably that the 50mm shot is out of focus, its focus motor's quite innaccurate in my experience.

[drisley]

No, it's not out of focus.
I did a few tests, and the 28mm always beats the 50mm.
And as I mentioned, the T is the focus point, and is the sharpest point in both images. As you move further back in the 50mm image, it gets softer, as it does as you move forward.
Also, the trident package isn't perfectly perpendicular to the camera. It's at a slight angle. So, if it was out of focus on the T, there would be some point on the package that would be sharper. But that is not the case.

[schmoelzel]

Hi Drisley:

Glad you kept the 28mm.....('cause with my lens addiction, I was thinking of taking you up on your sale!!). Now sell that thrifty 50 and get the 50F1.4..........just as you appreciate the quality of the 28mm, the 501.4 exudes the same quality feel.

[drisley]

You know, at first I thought the 28/1.8 was letting me down image-wise. But I have now realized, as I did with my 17mm, that shooting at wider angles you should expect a different result. There is often no creamy bokeh to make the focused areas look super sharp. Also, the lens will be taking in much more information at wider angles, so the apparent lack of detail can be blamed as much on the camera's resolution as anything.
Heck, last summer I took a "scenic", landscape type picture with my DRebel and 135/2L at F8, and I was shocked when I saw it at 100% because I expected each and every detail to be present and sharp, which was NOT the case at all.
I think you mentioned in another thread that you like when a lens gives you confidence to shoot.
Well, as much as I like the 50/1.8II, I didnt have the confidence to use it at the last fitness show, mainly because of the focus system, so I moved farther back and used my other lenses. I think that is a good indication of when it's time to get the 50/1.4 :)

[tim]

The 28mm lens definitely looks sharper to me.

My 50mm F1.4's going in next week for calibration. They want to me to send the body too, but since I have 4 lenses that work perfectly on the body I think i'll just send the lens - being without my single Camera for the 2-3 weeks it'd take would be quite annoying.

[drisley]

Yes, the results surprised me too, especially since I've seen comparisons that show the 50/1.8II to be sharper than the 35/2 lens. I will try to post more results tomorrow.
Btw, I too would dread having to send my camera in for servicing. It took over 1 month for Canon Service to apply a "simple fix" to my BG-E2 to remedy the flexing issue. In the end they sent me a new one with the same problem.
I would HATE to be without my camera for that long.

[tommykjensen]

I recently replaced my 50 1.8 with the 50 1.4 and this shot was taken while I was in Florida.

I like the results.

ISO 100
1/400
F5
100% crop
http://photo.klein-jensen.dk/photo.php?n=ef5014test.jpg

[drisley]

Yup, nice color and contrast.

[drisley]

I just did some further comparison test with these two lenses at different apertures.
I found that in some cases the 50/1.8II was sharper, and in others the 28/1.8 was sharper.
I think the conclusion is that they are both very close, and that any focus innacuracies (usually from the 50/1.8II) will scew the results.
Also, the different compression caused by the 2 focal lengths will produce quite different images.
The only thing I can say for sure is that the images from the 28/1.8 are definately warmer.
Both lenses are very good in their own right.

[tim]

Can you post pics demonstrating the different images produced by different focal lengths? I know what you mean, but it'd be interesting to see.

[tommykjensen]

You know drisley, You play a major role in me purchasing primes. You are talking me into buying the 28 mm 1.8 lens too......

[drisley]

Hehe, Tim, yes I will post some comparisons tomorrow or maybe tonite.
Tommy, I always worry that somebody will buy a lens based on my recommendations, and then be disappointed (well, not with the 135L or 85/1.8).
Don't necessarily base it on my rants, but rather the pictures. I sometimes can get overly excited about a lens, and perhaps be biased. But, if you like the quality of the pictures then I'm glad to have helped.

[tommykjensen]

Tommy, I always worry that somebody will buy a lens based on my recommendations, and then be disappointed (well, not with the 135L or 85/1.8).
Don't necessarily base it on my rants, but rather the pictures. I sometimes can get overly excited about a lens, and perhaps be biased. But, if you like the quality of the pictures then I'm glad to have helped.

Don't worry, I do look at the photos also before purchasing a lens. I bought the 85 1.8 when I was in Florida and I really like the results from that one so. But I do have to say that when looking at Your photos and reading Your thorough testing of lenses Your opinions weigh a lot on the plus side when I choose lens.

[drisley]

Tommy, I am glad that you find my opinion helpful :)
Well, I do say that this lens is in a class of it's own, much like the Tokina 17mm. There are no other 28mm lenses out there with such low light capabilites and USM. There is the Sigma, but I hear it's focus system isn't good at all.

As far as focal lenght compression goes, here is an animated gif showing a quick and dirty comparison. I did my best to make the main subject, the DVD case, to look the same in both images. You will notice a big difference inthe background (look at the door and the wheel). Not to mention, the 2 bottles look much closer to the DVD case (in distance from the camera) on the 50mm picture.
Both pictures were taken at the same height and roughly level, but the 28mm image almost looks as if it is pointed downward slightly (it's not).
It's rather interesting that such a small difference in focal length can make such a difference

.http://images2.fotop.net/albums/sharpnsmart/miscellaneous/comparison.gif

[tim]

Interesting, thanks Drisley.

[Persian-Rice]

Dris, there is something wrong here. Look at the text at the top of the package compared to the bottom, specially text on the bottom left. They are actually pretty close in sharpness when you compare that, however, the 28mm has better contrast. It's also logical to think the the 50mm would have a shallower DOF, which means it will also be less forgiving to errors. best is to have a poster to a wall with the camera perpendicular to it.

The 28mm shows the "pop" that most expensive glass shows, it's that absolutely fantastic color contrast. That is something I have noticed that cheaper lenses seem to lack. My 50mm and Tamron, which are my only relatively cheap glass, they both produce cooler images with weak color contrast, and its something I have a hard time accurately replicating on the computer. Even comparing on that animation you have, the colors of the same scene look more vibrant with the 28mm.

[drisley]

Persian-Rice,
Yes, I admit that the first images are not scientifically exact in any way. But, the focus point on both was the letter T. So, I guess if the AF of the 50mm is not accurate enough to give a sharp T, we have to take that into consideration as well. I think I was so shocked that the 50mm didn't "mop the floor" with the 28mm in terms of resolution that I may have jumped the gun a bit. Subsequent testing has shown that both are very close (and that is a good thing for the 28mm).

I also agree about the 28mm having nice colour and contrast. It is definately MUCH warmer than the 50mm. In fact, in the animation above I actually used a WB of 2850 for the 50mm shot, and 2750 for the 28mm shot to try to get similar colour values, and the 28 is still slightly warmer, as you noticed.

I guess I shouldn't have made this into a lens vs lens type thread. I was just curious as to how the 28mm compared to the next closest focal length I have, the 50mm. I've always found the 50mm lens to be pleasing optically, and if I could prove that the 28mm lens was close optically, than I would have nobody to blame but myself for poor pictures.

As Schmoelzel would say, I now have confidence in this lens, and I can "focus" on improving my own skills with this less forgiving focal length.

[Persian-Rice]

Drisley, I realized this along time ago, and this where I think people are very wrong in deciding on the quality of lenses. People only look at sharpness, thats it and nothing else. Actually sharpness on most lenses is so minimal that people need to crop to 100% and squint to tell the difference bbetween what they might call a good lens or a bad lens.

They don't look at the rendition of colors and the contrast within them, this is something manufacturers have realized, they make sharp lenses that produce pale and cool images and people love it because its cheap and sharp, but looks like ****, excuse my French. When I first got my 28-75 or 50mm, I thought to myself damn this is awesome, but upon further use, the images are so dead, they look like nothing that comes out of a good quality lens. The worse part is, the render the color a solid, there is no range in them and you cant fix that. I notice that in both of my lower quality lenses, they ruin bright colors,especially warm ones, specifically reds.

I think your comparison only shows this more then anything else. The 50mm might be sharp, but compared to a similar style of lens(normal, widish prime) with better quality and optics, it wipes the floor with it.

[drisley]

Btw, for further examination, HERE (http://www.mts.net/~lftbrain/20d/28_half.jpg) is an image taken with the 28/1.8 at F7.1, and resized 50%.
A few people have said this lens lacks detail on "far away" objects.
I found the lens did an exceptional job in this case, and did a very good job representing a normal focal length (what I saw with my own eyes).
Perhaps they were referring to wide open? But, I would never shoot a picture like this wide open, unless I had no other choice.

[tim]

That's a nice looking photo, nice colors, nice sharpness.

[Redbird_xo]

Shooting with primes is an addictive behavior! Alert!!! :lol:

I'm eyeing on the 24 f/2.8 at the moment...