[ChristianRock]

These look pretty good. I wonder how the cheaper SMC version compares.

In blown up flickr pictures, to me it looked a bit worse than the DA 18-55.

In the reviews section here, there's only an entry for the HD 18-50mm, so people who have the SMC version post in there - some say it's the SMC version, and some say it's the lens that came with their K-S2 (so yes it's the SMC).

The reviews average is 7.45 score with 73% recommending it. Basically, poor results. Average Cost is $135.29.

But I when I take out 5 reviews that were obviously for the SMC version, the ones left being the HD version (tough there's one that I wasn't sure about, with a score of 8, but I left it in there) - and now the average is 8.50 with 100% recommendation! Average cost is $167.25.

For the 5 SMC copies, the average rating was 6.20, with only 40% recommendation. Average cost was $95.51.

All of this looks about right to me! I think if the retract locking mechanism was better, the HD scores average would easily hover around 9, as that was the main complain people had.

I'm seriously impressed with this little lens, especially with the contrast, sharpness and colors wide open. It's a different look from my DA*16-50, which I think has finer details especially at f8, but in some ways it's better - how it handles light sources in the picture, for example. I think I won't compromise too much when I want to go light and go out with this instead of my DA*16-50. But I still have to use it with people, where the 16-50 shines - the texture of skin and hair are absolutely gorgeous with the 16-50. We'll see how they compare...

[ChristianRock]

So, it ended up happening - I bought both lenses... last week I received the HD DA 21mm Limited. That tells you what these threads do for your LBA

Having used both for a few days, including some informal comparisons in the front and back of my house, I thought I'd give some preliminary findings so far...

* They are both very sharp. In fact I have some shots where the HD DA 18-50 at f4 captured a stunning amount of detail, more so than the 21 Limited at f4. Those usually happened at high shutter speeds (more on that in a bit...)
* For some reason, the DA 18-50 at 23mm has the same field of view as the DA 21mm (I don't mind and in fact it makes it easier to find out which shot is from which lens...)
* In terms of color, they are very close. I seem to see a little bit more detail in the 18-50 - which might be better micro-contrast, and might be what I'm seeing what I described in the first bullet point
* The prime, of course, goes down to f3.2, so that is quite an advantage
* The zoom focuses quite a bit closer than the prime. The DA 21 is not as useful for closeups as I thought it would be. But the bokeh is of course a bit nicer.
* At wide angles when doing close-ups, the DA 21 is a bit sharper than the DA 18-50. But then if I go up to say 40mm or so in the DA 18-50, the closeups are just as good and the perspective is much better.
* At f8 the DA 21 is a bit sharper than the DA 18-50, but there's not much in it.
* The DA 18-50 seems a little better corrected in the frame edges for CA
* The DA 18-50 seems to be much more affected by shutter vibration/mirror shock

I'm going to elaborate more on that last point... I made these comparisons on two bodies that I didn't really consider to be problems as far as shutter/mirror shock: first the K200D then the K-3. With the K-3 and shutter speed of 1/50s, the DA 18-50 was pretty bad compared to the DA 21 - which was affected only a little bit. Get the shutter speed up to 1/400s and all pictures are now sharp as tack from wide open.

My two other "plastic fantastic" lenses seem to suffer from this as well - the DA 35 2.4 and the DA 50 1.8 (these are more used with the small K-S1 where this problem is more known - but the K-3 was a bit worse, probably because of smaller pixel size). The only thing I can think of is that these lenses don't have the tight tolerances that the DA Limiteds and the older manual Pentax lenses had, so when the shutter moves (it's probably more the shutter than the mirror, which already stopped moving at this point), something moves inside the lens and we know that even the tiniest of movements can cause a blur in the picture, if there wasn't a long enough exposure to compensate for it, or if the exposure wasn't so short that it would basically "freeze" that movement like it does with the subjects.

I'll see if later today or sometime this week I can test the K-3 with a flash on - that seems to solve most problems with shutter shock with the K-S1.

So, in conclusion, I think I still stand by my earlier opinion that if you need a small, moderate wide angle lens for your APS-C Pentax, I'd firstly recommend the HD DA 18-50mm f/4-5.6. If you can have both, like I am fortunate enough to be able to, it's worth having them. The main advantage of the DA 21 is the size and the fact that you don't really have to watch your shutter speed all that much. Optically they are very close and the zoom has quite a bit to offer - good close-up ability, WR and a DC motor are the main ones that set it apart from the prime.

But then, when you can, get the Limited as well... you'll be glad you did...

[seventysixersfan]

thanks for this comparison -- the DA 21 is a fun limited prime, super compact, and all metal. 18-50 offers zoom convenience along with the other benefits you mentioned. Good to know the zoom fares well in the image quality comparison to the limited. I say, own them both if possible! :-) Though I admit that sometimes I think I should sell my DA 21 and just use my DA 15mm and crop.

[Ronald Oakes]

I absolutely Love my little DA 18-50.
It's a bit quirky , different , and definitely cheap......but it fits me perfect and performs well.
Glad you came to good conclusions on this much maligned little lens.

---

Last edited by Ronald Oakes; 07-13-2021 at 06:37 PM.

[redrockcoulee]

Of I'm just going walking or cycling with no real intention for specific shots I usually take my RD 18-50 L DA instead of my limiteds. If wishing to travel light but still wanting to do some serious photography I take 3 of my limited with 2 of them in a lens case on my belt and the third on the camera.

The RE is light and has a decent range and is water resistant. You are not crazy to use it as a walkabout lens plus it's so cheap it does not exclude you from afterwards buying the limiteds. I have the SMC versions of the 15, 21, 40 and 70. Occasionally I might take the RD on the camera and the 70 and 15 in the belt case.

On the other hand if we end up going to Antarctica next year I'll probably pick up a used 18-85 for the small boat trips to landing and maybe on the kayaks.

Most posters here advise you to buy buy buy in order for their buying to appear normal.

[UncleVanya]

I have the SMC version of the 18-50. I need to give it a serious testing. I have an SMC DA 21 as well... hummm....

[ChristianRock]

Here they are on my K-S1 bodies...

Despite being larger, the HD DA 18-50 is actually noticeably lighter (all plastic...), so both are pretty portable.

[Bertrand3000]

So, it ended up happening - I bought both lenses... last week I received the HD DA 21mm Limited. That tells you what these threads do for your LBA Having used both for a few days, including some informal comparisons in the front and back of my house, I thought I'd give some preliminary findings so far...

Very interesting. I regret a bit to have sold the 18-50, but it was the DA-L version, which seems to be much inferior to the HD version by many reports, even if no one really knows why there is so much a difference. HD coatings never improved IQ that significantly for other lenses.

[Jonathan Mac]

So, it ended up happening - I bought both lenses... last week I received the HD DA 21mm Limited. That tells you what these threads do for your LBA

Having used both for a few days, including some informal comparisons in the front and back of my house, I thought I'd give some preliminary findings so far...

* They are both very sharp. In fact I have some shots where the HD DA 18-50 at f4 captured a stunning amount of detail, more so than the 21 Limited at f4. Those usually happened at high shutter speeds (more on that in a bit...)
* For some reason, the DA 18-50 at 23mm has the same field of view as the DA 21mm (I don't mind and in fact it makes it easier to find out which shot is from which lens...)
* In terms of color, they are very close. I seem to see a little bit more detail in the 18-50 - which might be better micro-contrast, and might be what I'm seeing what I described in the first bullet point
* The prime, of course, goes down to f3.2, so that is quite an advantage
* The zoom focuses quite a bit closer than the prime. The DA 21 is not as useful for closeups as I thought it would be. But the bokeh is of course a bit nicer.
* At wide angles when doing close-ups, the DA 21 is a bit sharper than the DA 18-50. But then if I go up to say 40mm or so in the DA 18-50, the closeups are just as good and the perspective is much better.
* At f8 the DA 21 is a bit sharper than the DA 18-50, but there's not much in it.
* The DA 18-50 seems a little better corrected in the frame edges for CA
* The DA 18-50 seems to be much more affected by shutter vibration/mirror shock

I'm going to elaborate more on that last point... I made these comparisons on two bodies that I didn't really consider to be problems as far as shutter/mirror shock: first the K200D then the K-3. With the K-3 and shutter speed of 1/50s, the DA 18-50 was pretty bad compared to the DA 21 - which was affected only a little bit. Get the shutter speed up to 1/400s and all pictures are now sharp as tack from wide open.

My two other "plastic fantastic" lenses seem to suffer from this as well - the DA 35 2.4 and the DA 50 1.8 (these are more used with the small K-S1 where this problem is more known - but the K-3 was a bit worse, probably because of smaller pixel size). The only thing I can think of is that these lenses don't have the tight tolerances that the DA Limiteds and the older manual Pentax lenses had, so when the shutter moves (it's probably more the shutter than the mirror, which already stopped moving at this point), something moves inside the lens and we know that even the tiniest of movements can cause a blur in the picture, if there wasn't a long enough exposure to compensate for it, or if the exposure wasn't so short that it would basically "freeze" that movement like it does with the subjects.

I'll see if later today or sometime this week I can test the K-3 with a flash on - that seems to solve most problems with shutter shock with the K-S1.

So, in conclusion, I think I still stand by my earlier opinion that if you need a small, moderate wide angle lens for your APS-C Pentax, I'd firstly recommend the HD DA 18-50mm f/4-5.6. If you can have both, like I am fortunate enough to be able to, it's worth having them. The main advantage of the DA 21 is the size and the fact that you don't really have to watch your shutter speed all that much. Optically they are very close and the zoom has quite a bit to offer - good close-up ability, WR and a DC motor are the main ones that set it apart from the prime.

But then, when you can, get the Limited as well... you'll be glad you did...

Buying both and comparing at the same time is always the best option if you can manage it.

Here they are on my K-S1 bodies...

Despite being larger, the HD DA 18-50 is actually noticeably lighter (all plastic...), so both are pretty portable.

Did that camera come with the old AOC logo on it or did you (or someone else) add it later? It looks nice.

[microlight]

Now that’s a decal I’d like to put on my K-3II!

[ChristianRock]

Buying both and comparing at the same time is always the best option if you can manage it.

Yeah I was fortunate enough to get great deals on both... The HD DA 21 especially, usually has a high resale value.

Did that camera come with the old AOC logo on it or did you (or someone else) add it later? It looks nice.

This was forum user pepperberry farm's K-S1, that he used on his Adaptist project (see here: Adaptist PK+MM installation and usage - PentaxForums.com)
I think he puts that sticker on all his Pentax cameras. I think he mentioned before where he gets them but I now don't remember...

[ChristianRock]

Very interesting. I regret a bit to have sold the 18-50, but it was the DA-L version, which seems to be much inferior to the HD version by many reports, even if no one really knows why there is so much a difference. HD coatings never improved IQ that significantly for other lenses.

Yes, usually that is the case.

I have a couple of theories... first that the HD version is just better coated. I think the SMC version has always been sharp (in its sweet spots...) but I think the micro-contrast just wasn't that good, and that can make a lens seem much less sharp.

There's something else I found while I was searching for pictures of both lenses... and it's totally speculative on my part... but I even bookmarked it... I hope the author of the picture doesn't mind me posting it here...



Now compare that to the optical design from Ricoh's site:



I could be totally wrong, but it seems like the flickr picture from the Pentax booth at CP+ shows an extra special glass in that lens, that is not listed. It's about in the center in both pictures.

In the lens description in the Ricoh site, it is listed that the main reason they released the HD 18-50 was to have a kit lens for higher resolution sensors. So it makes sense it was optically tweaked. But I'm probably wrong, since if they used more special glass in there than the old 18-55 design had, they would have listed it for marketing purposes.

[ehrwien]

I think the SMC version has always been sharp (in its sweet spots...) but I think the micro-contrast just wasn't that good, and that can make a lens seem much less sharp.

Can you explain the difference between sharpness and microcontrast? I thought that was almost the same, but I fail to see how they differ.

I could be totally wrong, but it seems like the flickr picture from the Pentax booth at CP+ shows an extra special glass in that lens, that is not listed. It's about in the center in both pictures.

Do you mean the thin thing between the doublets in the middle? Wouldn't that be the aperture?

[ChristianRock]

Can you explain the difference between sharpness and microcontrast? I thought that was almost the same, but I fail to see how they differ.

Microcontrast as I understand it would be like "color sharpness" - for your microcontrast to be good, ideally no colors will "leak" into the neighboring pixels.
Sharpness is about the lines and edges, and having those well defined.

Do you mean the thin thing between the doublets in the middle? Wouldn't that be the aperture?

No, I'm referring to the glass that has a different color - like the other two from the optical formula.
Again, it could be totally coincidental, but I thought it was interesting.

[UncleVanya]

Very interesting. I regret a bit to have sold the 18-50, but it was the DA-L version, which seems to be much inferior to the HD version by many reports, even if no one really knows why there is so much a difference. HD coatings never improved IQ that significantly for other lenses.

Several reviews I read showed virtually the exact same results on tests. I would love to see a double blind test to remove reviewer bias.