[mepopa]

Hi,
I'm owning a Sigma 18-50 mm f/2.8-4.5 for 9 years now and I am still quite happy with its results. However, as I have an opportunity to buy another Sigma lens, 17-50mm 2.8 (as a replacement), I would like to have your thoughts if it worths spending 350 euros on it.
Thanks!

[BigMackCam]

Welcome I've moved your post to a new thread, as it will be more visible to our members

[mepopa]

Thanks for the support. .

If a better replacement lens is proposed for a budget under 500 euros, I might change to it, given the arguments.

[BigMackCam]

Thanks for the support. .

If a better replacement lens is proposed for a budget under 500 euros, I might change to it, given the arguments.

You're welcome

I have the Sigma 17-50 f/2.8 HSM and it's an excellent lens - the major benefits being the constant f/2.8 aperture capability throughout the focal length range, and the fact that it's decently sharp wide open (though the borders improve as you stop down, which is to be expected). As such, it offers shallower depth of field (if that's something you find creatively appealing), but is also useful for keeping the ISO level down in lower light.

I don't own the Sigma 18-50 lens you mention, but I'm fairly confident the 17-50 f/2.8 would be a good step up. Whether it's worth 350 euro is really something only you can decide... but I've never regretted buying mine

[Gene D]

Thanks for the support. .

If a better replacement lens is proposed for a budget under 500 euros, I might change to it, given the arguments.

I have the f2.8 and can also vouch that it is an excellent lens--can't go wrong. You say you are happy with your current one, so not sure what other benefits you are seeking, but for me when I migrated to this lens I was going from the Pentax kit lens and it has been a world of difference. I like the ability to shoot it in lower light, , its very sharp, constant 2.8 and the bokeh is nice. If you look at the user reviews on this site you can see there is a good collection of recommendations for this lens. As for the price you'll know based on your location and Brussels market but I was able to purchase a very nice used one from a reputable dealer for around $250 US several years ago (located in the US), you may check the marketplace or even eBay. For what its worth, I did recently purchase a used Pentax 20-40mm Limited and have been impressed with it when traveling and also in cold/rainy/dusty weather. Used, it's probably in your range. For me it was due to the weather and travel (it smaller and more portable). It is a different camera in its range, ability, feel and color output but could be worth a look if you can borrow to test.

[ramseybuckeye]

I had the 17-50 2.8 and it is a very nice lens, I did end up selling it after getting the Pentax 20-40 (because being weather resistant and a Limited) I was no longer using the Sigma.. If you are happy with your 18-50 I would probably keep using it, I'm not sure the constant 2.8 would give you that much advantage.

[dronegeek]

The reviews here on the Forums are much better for the Sigma 17-50mm F2.8 than the Sigma 18-50mm. I have the Sigma 17-50mm 2.8 and it is one of my most used lenses. It is very sharp and I use it for portraits in close quarters when I do not have the room to use my Pentax DA* 50-135mm. I highly recommend the Sigma 17-50mm.

[mikesbike]

I have the Sigma 17-50mm f/2.8 and I remember seeing test reviews for both lenses. Based on my own experience with the Sigma 17-50mm f/2.8, and the lab tests I have seen, I am sure it is a superior lens.

[mepopa]

Thanks a lot for your feedback. I will make the deal then.

[ChristianRock]

I was surprised to see that the difference in size between the two lenses isn't that significant. The 17-50 2.8 is probably a bit heavier though.

See size comparison: Compact Camera Meter

With that in mind, and with the prices that these lenses are selling for nowadays (very affordable!), I think the newer 17-50 is almost a no-brainer.

(For disclosure, I don't have either lens. I thought about it, but I love my Pentax DA 16-45mm f4, and f4 is fast enough for what I use it for - and I much prefer the colors I get from Pentax lenses. If I were to buy a constant f2.8 lens, I think I personally would look at the Tamron 17-50 2.8, because I really like the look of the pictures taken with it)

[rogerstg]

I'm owning a Sigma 18-50 mm f/2.8-4.5 for 9 years now and I am still quite happy with its results. However, as I have an opportunity to buy another Sigma lens, 17-50mm 2.8 (as a replacement), I would like to have your thoughts if it worths spending 350 euros on it.

Since it's a lens you're happy with, you'll be spending 350eu for 1mm extra width and slightly faster aperture in the long end. Is that worth it to you? It's unlikely that you'll notice any difference in image quality, though you may think you do due to confirmation bias, post purchase rationalization and the bandwagon effect.

[BigMackCam]

It's worth checking out the LensTip review summaries for both lenses, as they may help with the decision...

Sigma 18-50 mm f/2.8-4.5 DC OS HSM

Pros:

• Tight lens body that doesn’t change its dimensions
• The presence of image stabilization and HSM in this price class
• Very good or even great image quality at the center of the frame for all focal lengths
• Slight chromatic aberration for longer focal lengths
• Well-controlled astigmatism
• Quiet and accurate autofocus

Cons:

• Poor image quality at the edge of the frame, especially visible at the widest angle of view
• Large chromatic aberration at 18 mm focal length
• Noticeable coma
• Quite large vignetting in the whole focal length range
• Work against the bright light might be better

Sigma 17-50 mm f/2.8 EX DC OS HSM

Pros:

• high build quality and very solid barrel,
• sensational sharpness of images in the frame centre even at the maximum relative aperture,
• decent image quality at the edge of the frame,
• chromatic aberration well-controlled at longer focal lengths,
• negligible astigmatism,
• silent, quick and accurate autofocus,
• efficient image stabilization,
• three-year-long guarantee period with the possibility of extending it by additional two years.

Cons:

• noticeable chromatic aberration at the shortest focal length,
• a bit too high vignetting,
• significant coma at 17 mm,
• too simplified manual focus ring,
• image quality at the maximum aperture, at the edge of the frame for shorter focal lengths could have been better.

[Piotrek K]

You can always resell 18-50 here if 17-50 works for you.

[mikesbike]

The Sigma 17-50mm f/2.8 also tested having practically zero field curvature, an exceptionally good result for a wide-to-short tele zoom lens. Whether its virtues are worth the cost is an individual matter. I do a fair amount of low light photography, where this lens pairs well with my DA* 50-135mm f/2.8 lens. But I do use it a lot for a great all-around zoom lens as well as for action shooting where it can allow a higher shutter speed.

As far as a semi-fast but very compact alternative, my DA 20-40mm f/2.8-4 is a favorite for me when I want to go lighter and don't need the f/2.8 aperture throughout a longer zoom range.

[mepopa]

I will receive the lens today. Among the key features I was looking for the new lens, the price, the noise level and the low light performance were the most important. I will do the comparison between the lenses myself (although they will be mounted on 2 different Pentax-es, a KP and an old K5).