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11-07-2016, 08:40 AM - 1 Like   #1
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A comparison between the DA21 LTD and FA28 (with pics!). Mainly for starbursts

I've been using the DA21 MTD (not the HD version) for a while. In the recent years, it has been used for principally one single purpose : night photography, especially cityscapes. And for that it shines, so much so that it's my go-to lens for such applications.

However, I recently acquired a K-1 and was wondering if there was a full frame compatible lens capable of delivering similar results while taking advantage of that high resolution sensor. The 21 has superb colours, good sharpness without being the "best", some distortion that's hard to note in real life, but mostly it creates superb starbursts. That's its main perk:





I chanced upon a FA28mm and decided to acquire it and compare both. Considering that the DA21 is APS-C only, I set my camera to APS-C in order to compare apples with apples. I looked at resolution, starbursts, and a few other things. Here goes (right side is always DA21). Click for high-res.

Focus point crop at F3.2


Same at F8


Focus point crop at F5.6 (different frame)


Near the focus point at F5.6


Out of focus area at F3.2


Center of the frame, wide open for both lenses


Same at F8


Bottom edge wide open for both lenses


Same at F8


Corner wide open for both lenses


Same at F8


The conclusion of that short series is that, apart from the focal length, there isn't much to differentiate the two lenses. They are quite comparable, which shows how capable the 28 is. Based on this, either could serve me well.

Now for some starbursts. Here is the scene I used:



Here is a crop at F4:


Smaller crop at F4


Same type of crop at F8


Disregard the fact that the 21 was dusty (which I saw after the test).

While the 28 performs decently, the DA21's advantage is pretty clear. In particular, the odd number of aperture blades helps create more defined rays of light.

The DA21 is smaller, lighter, has a semi-built-in hood and a metal body. It has quick-shift. The FA28 is still very well made in itself and both are durable.

This comparison makes deciding difficult. I haven't found a lens compatible with FF which delivers the kind of results the DA21 (and DA15 for that matter) can offer. I have heard that the F28mm is not as sharp as the FA28, but that its 5 aperture blades deliver pleasing starbursts. It's mighty rare, however (in fact, the listing I saw was for the F28, but I got the FA. No complains of course). The FA31 would yield the same FOV as the 21, but its 9 aperture blades mean that the aperture is more or less a circle, so no starbursts there.

I'm interested in opinions!

11-07-2016, 08:58 AM   #2
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The FF equivalent FOV for your 21mm would be the Pentax smcP FA 31mm f/1.8 Limited. 9 aperture blades...and as far as I know, they are not rounded. Can anyone verify this?

Optically I canʻt imagine youʻd be disappointed with this prime on your K-1.
11-07-2016, 10:17 AM   #3
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You will probably find that both lenses will give you a star burst pattern as this is due to the sensor's grid pattern. It is interesting to see how the two lenses effected the star burst patterns, most easily seen on the string of light.

regards,
11-07-2016, 10:25 AM   #4
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QuoteOriginally posted by Alex645 Quote
The FF equivalent FOV for your 21mm would be the Pentax smcP FA 31mm f/1.8 Limited. 9 aperture blades...and as far as I know, they are not rounded. Can anyone verify this?
Yep, I did mention the 31, with its 9 straight blades. Based on experience, 9 blades will loook mostly circular, so no starbursts.

QuoteOriginally posted by BigDave Quote
You will probably find that both lenses will give you a star burst pattern as this is due to the sensor's grid pattern.
nope, the starbursts are mainly caused by the aperture shape.

11-07-2016, 11:13 AM   #5
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QuoteOriginally posted by bdery Quote
Yep, I did mention the 31, with its 9 straight blades. Based on experience, 9 blades will loook mostly circular, so no starbursts.
Your 21mm has 7 blades, correct? Yes, a 9 sided polygon (nonagon) is similar to a circle than a heptagon, but with straight blades you are still going to get that starburst effect but with even more rays. Of course, you can always just use an 8-point star burst effect filter although you'll compromise your odd rays for even.

Hoya 77mm (8 Point) Star Effect Glass Filter S-77STAR8-GB B&H
11-07-2016, 12:17 PM   #6
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The FA 31 can produce starbursts. They lines aren't as crisp as those you'll find on the DA 15 or DA 21, but they're there.

Some examples from Mike Oria. These were shot on APSC, so I'm not sure how it would translate into FF:

Night In Old San Francisco | Rain puddle reflection from Pie? | Flickr

Spokes | please press L for lightbox The sun sets behind Mt.? | Flickr

Happy New Year! | Please press L to view in LIGHTBOX Here is? | Flickr
11-07-2016, 01:17 PM   #7
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QuoteOriginally posted by EarlVonTapia Quote
The FA 31 can produce starbursts. They lines aren't as crisp as those you'll find on the DA 15 or DA 21, but they're there.

Some examples from Mike Oria. These were shot on APSC, so I'm not sure how it would translate into FF:

Night In Old San Francisco | Rain puddle reflection from Pie? | Flickr

Spokes | please press L for lightbox The sun sets behind Mt.? | Flickr

Happy New Year! | Please press L to view in LIGHTBOX Here is? | Flickr
I think the FA31 starburst is a little bit better on FF.
However it's still not as sharp and crisp as the starbursts from DA15&DA21
_IMG1798

11-07-2016, 01:37 PM   #8
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Although it is not an effect I often try to elicit, the FA31 can produce nice clean starbursts. You'll need to view at higher magnification in flickr to fully appreciate them.



Personally, I find 18 point stars a bit busy and prefer the 14 pointers from the DA15 and DA21, which are uniquely wonderful in this regard. Although my lens collection is being tailored for full frame, these two lenses aren't going anywhere.

I did own a F28/2.8 for a while, but never got to test it for its starbursts. It was a nice compact lens with good IQ, but it was never going to replace my FA31 for general use, so I couldn't justify keeping it.
11-07-2016, 01:48 PM   #9
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QuoteOriginally posted by Alex645 Quote
Of course, you can always just use an 8-point star burst effect filter although you'll compromise your odd rays for even.

Hoya 77mm (8 Point) Star Effect Glass Filter S-77STAR8-GB B&H
Not a fan of adding extra stuff in front of my lens, but thanks for the suggestion.It's not the amount of lines that I'm digging, per se, but their size and definition.

QuoteOriginally posted by EarlVonTapia Quote
The FA 31 can produce starbursts. They lines aren't as crisp as those you'll find on the DA 15 or DA 21, but they're there.
Well, I WOULD love to own the 31, but it's still a wee bit expensive (selling both the 21 and 28 wouldn't cover it, probably). I'll try to find other examples of nighttime results with it.

QuoteOriginally posted by Sandy Hancock Quote
Personally, I find 18 point stars a bit busy and prefer the 14 pointers from the DA15 and DA21, which are uniquely wonderful in this regard. Although my lens collection is being tailored for full frame, these two lenses aren't going anywhere.
Thanks for that further example. I'm beginning to think the 21 is, indeed, pretty unique. Here's a comparable setting to your image, but with the 21:

11-07-2016, 04:11 PM - 2 Likes   #10
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Nice comparison of the DA21 and FA28. I have both as well, and (as I don't have a K-1) on APS-C I tend to prefer the 21 for indoor use and the 28 more for out of doors. That's more to do with focal length than anything else. For my copies, though, the 28 looks sharper at infinity, while the 21 is really good up close.

QuoteOriginally posted by bdery Quote
I'm beginning to think the 21 is, indeed, pretty unique. Here's a comparable setting to your image, but with the 21:
I think the 21 and the 15 aren't that different when it comes to starbursts. A recent image with the DA15.

11-07-2016, 04:23 PM   #11
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Your sunset looks like Lanai shot from Maui. Or is that Kahoolawe?
11-08-2016, 12:37 AM   #12
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QuoteOriginally posted by bdery Quote
Well, I WOULD love to own the 31, but it's still a wee bit expensive (selling both the 21 and 28 wouldn't cover it, probably).
Yeah, I had an FA 31 last year, sold it, kinda regret it. It was definitely an amazing lens.



On the point about DA 15 SMC vs DA 21 starbursts, the DA 15 SMC is unique in that it's the only lens I know of where the starburst points are different lengths (the points go long-short-long-short . . . )

Here's an example from the DA 15 club:

https://farm3.static.flickr.com/2707/4260763026_df984042ae.jpg

You'll see it in other DA 15 photos, particularly where the sun is present.

I'm actually curious if there's another lens that can produce such a starburst.
11-08-2016, 12:58 AM - 1 Like   #13
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QuoteOriginally posted by Alex645 Quote
Your sunset looks like Lanai shot from Maui. Or is that Kahoolawe?
It's from the Canary Islands - La Gomera shot from Tenerife. Would very much like to visit Hawaii, though!
11-10-2016, 05:44 AM   #14
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To add to the discussion : should the FA*24 F2 be considered in this comparison? On paper it appears to be a beautifully spec'ed lens, however tests don't always make it shine. I have not seen how it performs regarding night cityscapes, and it has 8 aperture blades which isn't ideal. Corner sharpness doesn't seem impressive either, but many owners swear by it.
11-10-2016, 11:09 AM   #15
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QuoteOriginally posted by bdery Quote
To add to the discussion : should the FA*24 F2 be considered in this comparison? On paper it appears to be a beautifully spec'ed lens, however tests don't always make it shine. I have not seen how it performs regarding night cityscapes, and it has 8 aperture blades which isn't ideal. Corner sharpness doesn't seem impressive either, but many owners swear by it.
Yes, absolutely. In fact, the FA 24mm is closer to the starburst renderings of the 21mm vs. the 28mm.
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