Compare and contrast: HD Pentax-D FA 24-70mm F2.8 with HD Pentax-D FA 28-105mm F3.5-5.6

If anyone has used both the HD Pentax-D FA 24-70mm F2.8 and HD Pentax-D FA 28-105mm F3.5-5.6, I would appreciate a brief comparative analysis between the two. I understand that the former is heavier, faster, wider and more expensive, but am interested to know how they compare as lenses for landscape and architecture, especially for printing up to 12" x 16".

I do have the HD Pentax-D FA 28-105mm F3.5-5.6 which I do enjoy using a great deal, it spends more time on the K-1 than any other lens, but am wondering if the difference in quality is a step up with the 24-70mm F2.8.

As to image quality there isn't much to choose. Obviously the former is faster, wider and significantly heavier, the latter is slower, longer and lighter! If a faster lens is needed for sports or theatrical work then the former is useful otherwise the one you've got does the job.

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John K

I tend now to use the 28-105mm as a lightweight walkabout option for general use, and it does give excellent results. However in more challenging light and where the extra width is needed in landscapes and architecture the 24-70mm is the lens of choice, in reality it is probably the lens I use more than any other. You have the constant f2.8 throughout and that comes at a price in cost and weight but the extra one or two stops extend your handheld options.

When I first got the 24-70 I did a wide end comparison with my 28-105. Tripod, mirror up, delayed release, f5.6. The result surprised me. Centre sharpness was similar but edge sharpness was better on the 28-105. The 24-70 showed significant barrel distortion, the 28-105 had very little distortion. Not exactly a like for like test as it was comparing 24mm vs 28mm but still interesting. I like the punchiness of the images from the 24-70 but if you are expecting a huge step up in quality over the 28-105 I think you will be disappointed.

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Regards, Philip

Thanks for the advice guys, it has been very helpful indeed:

I see the disadvantages in terms of speed, width, and weight, John, and given that I seldom if ever take sports or theatrical type photos, I guess the 24-70 offers less than I would benefit from.

Rob, although light is sometimes an issue with architecture (interior) shots, or night scenes in urban and evening landscape situations, yet in these scenarios I tend to prefer the greater depth of field that is offered with a more closed down aperture where of course a tripod or other form of support is needed (walls, lamp posts, trees come to mind). For that extra width, there is the 15-24, a beast to carry around but always worth the trouble.

Philip, I think you have saved me approx £1,000, thank you! It is reassuring to know that at least when at maximum angle, the 28-105 betters the 24-70 in terms of sharpness (and barrel distortion). I have just been looking at the sample photos on this site, and it appears that the 28-105 is not only sharper at edge comparing 35mm focal length, but noticeably so at edge comparing 70mm focal length.

Given that I don't usually need F2.8 (I have other lenses for portraits, or picking out detail etc), and that I have the wider angle in the 15-30, I will be happy with with what I have. Pentax's so called kit lenses; the 28-105 for FF and the 16-85 for APS-C are exceptionally lenses, and good value for money.

The lesson to me is; worry not about hardware, focus on developing a higher level of photographic skill and compositional creativity!

Just found this thread that's very helpful. Seems I may not be doing the deal after all and sticking with what I've got already.

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Gareth
Welsh Photographer

My outfit: K1 gripped - Pentax D FA 24-70mm - Sigma 70-200mm OS HSM - Pentax modified DA* 60-250mm f4 - Irix 15mm Firefly - Pentax FA 35mm - FA 50mm - Tamron SP 90mm macro - Pentax AF 540 FGZ II

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For me the 28-105m punches well above its weight for the mentioned reasons. The difference between the two in real world usage is not worth the additional spend imho. #2pennysworth

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