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01-03-2010, 03:10 PM   #31
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No, you're wrong Gregg. The 31mm image was taken at f/1.8 1/180s, and the 16-50 was taken at f/2.8 1/180s. It says it right in the exif. Ben_Edict is right. You are not even comparing the lenses equally, so no, "the fact the shots look so similar to all tell me the differences in optical quality are minimal" is not true at all. You also resized the images, and half of the frame of the snow one is overblown, and you put some kind of weird border on the left of the 16-50 image. You cannot compare edited and sampled-down shots in CS4, you have to compare raw shots, or at least full-sized crops from JPEGs direct from the camera.

You are making a faulty comparison, and it seems you don't have enough camera or optical experience or ability to tell the difference between images to warrant the purchase of either of the high-grade lenses being compared in this thread. Perhaps you would be better suited with a pocket digital camera.

01-03-2010, 03:42 PM   #32
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The biggest difference I see is actually in the indoor shot. If you look at the photograph of the baby on the right side of the frame (wearing the hat), the image taken with the 31mm 1.8 is clearly far sharper than the same area of the frame taken with the 16-50. Of course the focal length is different here (you set the 16-50mm to 28mm) which might account for some of the difference, but even accounting for that I find the 31mm dramatically sharper on the right side of the frame.

On the outdoor shot, the exposure differences are pretty glaring (pun intended), making comparisons more difficult, but in the 16-50mm image I see increased vignetting in the upper right corner, and in the upper left corner, the pine needles appear to be noticeably softer than the same area of the image captured with the 31mm lens. You can also see increased vignetting in the lower right of the 16-50 image in the snow.

So, I would say the 31mm LTD looks better in these two examples. In the indoor shot, pretty substantially better -- though some of that response might be emotional based on the fact that it is a better exposure and zoomed in a little tighter.
01-03-2010, 04:32 PM   #33
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Hi

Wally:

Thanx for the correction. I actually meant to take an image with each at their widest, so my intent was correct--my posting was in error. The indoor shots were at the same f stop, but it looks like I zommed to 28, not 31. So, these were my errors in doing something quickly today.

I have been using the lenses for the last copuple of weeks and simply seemed to notice little between them. Perhaps, I was not "pushing" the lenses and I recognize that differences between good and great optics can be nuanced.

I had the Sigma 24 and definitely noticed problems with it. Not necessarily defective, just clearly inferior--even to my eyes. I also had trouble with my first 16-50 lens. It had problems giving a sharp image at just about any focal length. My next copy of the 16-50, which I now have, is great, but of course the AF malfunctioned and the lens was at Pentax for 7 weeks.

I appreciate all of your input and like direct blunt criticism--so I take no offense, but I respectfully do not think I deserve the sarcasm. Nonetheless, I appreciate your assistance, given so quickly, along with that of everyone else.

Gregg
01-03-2010, 04:37 PM   #34
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QuoteOriginally posted by lawjbm Quote
I appreciate all of your input and like direct blunt criticism--so I take no offense, but I respectfully do not think I deserve the sarcasm. Nonetheless, I appreciate your assistance, given so quickly, along with that of everyone else.
There is no sarcasm in my post.

01-03-2010, 06:48 PM   #35
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QuoteOriginally posted by lawjbm Quote
Hi all:
I know another member indicated this may simply show how good the 16-50 is. Gregg
Well, my 16-50 is nowhere close to the quality of my 31 Limited...!
01-03-2010, 07:54 PM   #36
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I wanted to post yesterday but since there was no image posted, I wasnt sure at how to answer...

Looking at that, here's my take on it:
Lenses' characters does not show on test shots at all. I bet if you're comparing the ones you took, the kit lens can do almost or just as good job at it at f/8

If you want to see how well a lens really performs / why is it so special, you should go out and shoot!
01-03-2010, 08:54 PM   #37
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In my opinion: the outdoor shots all have horribly blown highlights, so it's tough to determine much. However, if you look at the yellow label on the red ladder, you can see that it's much clearer in the second picture than in the first. But then the first picture is at F1.8, and the second at F2.8, while the shutter speeds remained the same for both. So obviously the first one (31mm Limited) will look brighter, more washed out, and less clear. There are other similar differences throughout the pictures too. If the snow wasn't all blown out and the apertures were the same, it might be possible to determine some differences in the texture of the snow itself, but that's not the case.

Unfortunately, the indoor shots are not a good example to judge by, so that can't really be used as a comparison either.
01-03-2010, 09:42 PM   #38
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Good lenses cost money.
Having one good lens doesn't negate the value or cost of having another good lens.
The 16-50 is a good lens.
The 31/LTD is also a good lens.
Both are relatively expensive lenses because they are both good lenses.
This isn't hard.

01-03-2010, 10:03 PM   #39
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QuoteOriginally posted by Wheatfield Quote
Good lenses cost money.
Having one good lens doesn't negate the value or cost of having another good lens.
The 16-50 is a good lens.
The 31/LTD is also a good lens.
Both are relatively expensive lenses because they are both good lenses.
This isn't hard.
I think his concern is that his DA* 16-50mm makes his DA Limited 31mm redundant because his DA* is more flexible, includes 31mm in its range, and offers the same IQ. I'd be a little concerned too, considering how much these lenses cost. If it were true, then that's $1000+ that could've been used to buy other lenses or accessories... or pay back the mortgage sooner

But it's still a moot point. The only thing the pictures he posted prove is that the 31mm is in fact a faster lens since it was brighter at F1.8 than the DA* at F2.8. This isn't exactly revelatory material.

Honestly, I had the same concern when I got my DA* 50-135mm. Initially, I was pixel-peeping so hard that I was disappointed in its results. Sure, it was sharper than the 18-55mm WR kit lens, but not THAT much sharper (with both at 50mm). I was wondering why I bothered to spend so much money on something for a couple pixels' worth of sharpness. I could've just gotten a less expensive zoom lens in a similar focal range and saved a lot of money.

But then I stepped back and had a look at the overall picture. That's when I realized the DA* had vastly superior colour and contrast on top of the improved sharpness. The bokeh was incredibly smooth. The whole picture just looked "better", by leaps and bounds. I didn't appreciate the improved overall IQ until I stopped staring at the pixels themselves. I also eventually realized the enormous benefits of the larger aperture over the kit lens' lame F3.5-5.6 range.

I don't know if that's the case here for the OP, there just aren't any proper pictures to judge by yet.
01-04-2010, 03:11 AM   #40
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QuoteOriginally posted by Wheatfield Quote
Good lenses cost money.
Having one good lens doesn't negate the value or cost of having another good lens.
The 16-50 is a good lens.
The 31/LTD is also a good lens.
Both are relatively expensive lenses because they are both good lenses.
This isn't hard.
Agree 100%

Horses for courses... I love both of these lenses and if I didnt I would not have and use both.




Neil
01-04-2010, 03:22 AM   #41
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I think both lenses are out-resolving the photographer at the moment.
01-04-2010, 03:43 AM   #42
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Hi all

Thanx so much for all of your input.

I regret my sample pictures were not varied and better chosen.

After looking at the pictures I have taken over the last few weeks and taking some more time to look at the images I can see the differences between the lenses, but they still appear to me not so significant. The downside of pixel peeping. Not seeing the forest for the trees.

Perhaps that goes to the quality of the 16-50 and the often repeated observation that one usually pays quite a bit for small improvements in performance in already very good optics.

I bought the 31 to give me some back up and after I had tried less expensive lenses (the Sigma 24 and 18-55 WR). Both were inferior even to my eyes.

I also think I made an error, or at least was expecting too much for the types of shots I tend to take. I am beginning to do portrait work in my home studio. I use off camera flshes with a radio trigger and thus generally shoot at 5.6 or above. When I go below, to emphasize bokeh, I use the DA* 55 1.4 since I generally am doing head shot portrait work and try to stay away from wider lenses for that. So, I think my overall error was expecting to see that much of a difference in the narrower apertures I generally use.

We also have 3 children and I shoot quite a bit of them with the DA* 55 1.4 in lower light without a flash at wider apertures. Those are more candids and I could use the 31 for those and perhaps would see generally superior color, sharpness, etc., except the 55 is already very good and though more confining given the focal length, has become a favorite of mine to use.

Anyway, I think I may have purchased a sportscar when I generally use the car for travelling at highway speeds. I also think I may have been a bit frantic given I was doing a number of shoots while my 16-50 was in the shop for so long and wanted a quality back-up. When the Sigma 24 and 18-55 WR showed to be significantly inferior (though, it would be incorrect to say they were bad lenses--they were not) I stepped up to the 31 over the Sigma 28 or 30--since I did not want to go with another Sigma.

Anyway, I also am sure that at this point with photography I simply may not be able to fully appreciate the subtle differences between superb optics and very good optics and unwilling to pay that premium right now. Also, I tend to post process in CS4 quite a bit. This no doubt helps to cover up my mistakes, but also likely significantly erodes the differences between the lenses. As I become a better photographer and use CS4 as less of a crutch I likely will be able to better appreciate the qualities of lenses, along with other equipment.

These issues, though, are troublesome for people like me. Far enough with photography to make it the time to step up to equipment that is higher in quality and also able to provide more flexibility, but perhaps not so far long that nuanced differences are not that significant. I know--just go out and shoot more. Enjoy and gain experience. This reminds me of weightlifting. I competed for years and did well in my weight class and also do a lot of martial arts. I have friends who complain or comment about working out and not being able to get in a workout without having all of this premium equipment at a gym. I can get a workout pretty much anywhere--with equipment that is pretty low standard, and often without any equipment at all. That is because I have been lifting for 20 years. So, I understand I am at the beginning here, but these purchasing choices still remain difficult and I imagine these mistakes and "boo boos" at this point constitute learning experiences that will make me a better photographer many years from now.

Thanx again for the discussion. I appreciate everyone's assistance and criticisms.

Gregg

Last edited by candgpics; 01-04-2010 at 04:05 AM.
01-04-2010, 09:21 AM   #43
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For me the difference is down to bokeh.

The 31 will give images with graduated, smooth bokeh, helping the subject pop off the paper/screen.

To my mind (and many others), it does that better than most other lenses, certainly at that length.
01-04-2010, 10:04 AM   #44
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After this fairly...um...spirited discussion, I think you deserve a tip of the hat for your very thoughtful post, Gregg. It seems that questioning the 31mm ltd is about as close to heresy as you can get around here. I have one and it's given me some nice photos but, like you, I haven't been "blown away" by it (as I have been by the 77mm) yet. I think that's probably both my failing and because I haven't used it in the situations where it excels but I think an "ah-ha!" moment awaits me.
01-04-2010, 10:48 AM   #45
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I am confused as to how the 31 being as sharp at f1.8 as the 16-50 is at f2.8 is an "issue". It seems to me that is a good thing.
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