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Sigma 170-500mm F5-6.3 APO

Reviews Views Date of last review
15 57,434 Fri October 18, 2019
Recommended By Average Price Average User Rating
93% of reviewers $457.40 7.67
Sigma 170-500mm F5-6.3 APO

Sigma 170-500mm F5-6.3 APO
Sigma 170-500mm F5-6.3 APO

This is the full frame predecessor to the DG (digital) version.

Weight: 1,345g/47.4 oz
Length: 232mm/9.1 in
Filter Diameter: 86mm
Min. Focus: 300- 320cm/118.1-126.0 in
Max. Magnification: 1:6.6
Diagonal FOV:
Horizontal FOV: 14.5 - 5 degrees
Horizontal FOV on Digital: 9.7 3.3degrees
Min. Aperture: F32
Optical Construction: 13 Elements in 11 Groups
Mount Type: Pentax KAF3 (in-lens AF only)
Price History:

Add Review of Sigma 170-500mm F5-6.3 APO
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Junior Member

Registered: January, 2018
Posts: 44
Lens Review Date: October 18, 2019 I can recommend this lens: Yes | Price: None indicated | Rating: 9 

Pros: price, image quality with some reservation
Sharpness: 9    Aberrations: 9    Bokeh: 9    Handling: 7    Value: 9    Camera Used: Pentax K-1    Autofocus: 8    New Or Used: Used   

I bought my copy on-line and ended having a copy with a lot of dust internally but the seller negotiated the price down a little bit so I ended up with an almost acceptable price given the condition. I would have happily paid the full price for a perfectly good copy, so my paid price was a compromise. (Will not display the price here as it is based on negotiations after receiving an item which was clearly worse than advertised and would distort the price image for a good copy). My copy also looks very heavily used with a lot of dents and scratches. The metal mount also has some play. The dust inside the lens clearly affects the image quality when shooting in back light conditions. My plan is to take it apart and clean it, and if not succesfull, I will lose some money in the deal.

There is a horrible zoom creep, which is not surprising for this lens type. The lens hood also cannot be fastened very tightly on the lens.

Apart from these issues, the lens is surprisingly good, at least optically. Especially, there is no sign of any focusing issue even when the object is far away. In earlier reviews, this has been named a few times. While I cannot say this could not be occurring in someone's copy (although cannot see how that could be), I am however quite sure that this does is not the case in my lens. I have the lens in cold arctic climate with no air pollution at all, and the images are crisp and clear even when shooting mountains which are 50km away. I would attribute some of the earlier reviewers' issues to atmospheric phenomena and probably also not having a robust enough tripod.

I have now used the lens both handheld and mounted on a tripod. For tripod use, it must be completely still day with no wind at all, and it is a good idea to use a wireless remote control. Handheld, the percentage of good images is clearly decreasing, but you will occasionally get one or two with short enough exposure time. You increase the likelihood of success when it is 1/1000sec or faster. You will also want to step down your lens from the widest aperture, so this clearly means that handheld shooting is not a night-time thing.

I think the lens focuses well. I have about 15 different lenses (including modern DFA lenses as well as older and cheaper film-era Sigma and other third party lenses) and this lens is among the better focusing older lenses.

With good light conditions, this lens performs pretty nicely. In dull light, it looks soft, and I do not know how much of this is caused by the thick layer of dust my copy has inside. However, based on my tests so far, having used the lens on a couple of longer trips, for a few hundred shots, this lens clearly deserves a better mark than it currently has in most of the reviews.

Edit: After cleaning, the images are crisper. There were many loose screws inside, some were close to falling off (inside the lens!) and tightening them, as well as cleaning the lenses, helped change the feeling of the lens to much better. I also tested the vignetting, so far only at 190mm. Heavy vignetting occurs when shooting wide open and it is noticeable until f/10 and gone at f/11. I would guess vignetting will be less severe at 500mm. Will update this review when I get to shooting with the lens again.

Loyal Site Supporter

Registered: February, 2014
Location: Pennsylvania
Posts: 698
Lens Review Date: July 10, 2019 I can recommend this lens: Yes | Price: $375.00 | Rating: 8 

Pros: Range, Close Subject Performance, Weight
Cons: Ergonomics, Soft past 350mm, Dust intrusion
Sharpness: 8    Aberrations: 8    Bokeh: 7    Handling: 6    Value: 9    Camera Used: Pentax K-5iis    Autofocus: 7    New Or Used: Used   

I have a love/hate relationship with this lens. Give it good light and a subject close enough, results can be nearly spectacular. Wonderful lens for insects on wildflowers, close birds and medium distance larger mammals. Unfortunately when zoomed past 350mm sharpness drops quickly and chromatic aberration becomes a real issue. I have many images of birds taken at 400-500mm which are good enough for social media posts but would never yield an acceptable cropped print.

For a big lens, the Sigma is fairly light and can be handheld if one uses proper technique! A sturdy monopod helps greatly, however results at the long end or with subjects more than 70 meters away leave much to be desired. Autofocus is hit or miss. My best results have been manually focused, which, unfortunately is not particularly easy due to the location of the focus ring.

I am at least the third owner of my Sigma 170-500mm and it is still in fine mechanical and cosmetic shape. Good build quality for a consumer grade lens. That said, this lens has picked up internal dust very quickly with most of it being in the hard to access lens groups toward the diaphragm. A lens hood is an absolute must for this lens as flare will ruin the contrast of side lighted subjects without it.

All in all, the Sigma 170-500mm makes a good entry level super telephoto zoom if you learn how to use it to best advantage. Past 350mm the images are just not up to critical use unless no further enlargement is needed. Still, for the $325 to $425 most used copies sell the lens performance to price make it a good value.
New Member

Registered: September, 2013
Posts: 1
Lens Review Date: March 20, 2017 I can recommend this lens: Yes | Price: $70.00 | Rating: 8 

Pros: Inexpensive, easily handheld
Cons: Soft above 350mm
Sharpness: 8    Aberrations: 8    Bokeh: 8    Handling: 9    Value: 10    Camera Used: Pentax K7    Autofocus: 9    New Or Used: Used   

This lens can give good results with a bit of practice & patience. Up to 300mm the performance is comparable to an HD 55-300 but soft beyond. I prefer hand held to a tripod & have found that using TAv mode (1/2000; f8 up to 300mm & 1/2000, f9.5 beyond) in bright light gives the best results. The ISO is generally in the 400-800 range so noise is not a problem.

A better sensor such as found on a K5 or K3 would give acceptable results in less light. The later DG version may be a bit better but this lens is some way behind the impressive Pentax D-FA 150-450.

A good option If you are on a tight budget.

I have now sold this lens & purchased a S/H DG version which is sharper at longer focal lengths (see my review).

Range 20m (cropped)

Range 500m (cropped)

Range 1km (cropped)
New Member

Registered: June, 2016
Posts: 1
Lens Review Date: June 1, 2016 I can recommend this lens: Yes | Price: None indicated | Rating: 7 

Pros: cheap option for bird photos
Cons: slow focus - needs thought to get sharp image
Sharpness: 7    Aberrations: 8    Bokeh: 8    Handling: 7    Value: 8    Camera Used: K3    Autofocus: 7   

[ Needs thinking about to get good results - not one just to just stick on and shoot - initially discarded a lot of shots - but getting the hang - not fast with birds -
Loyal Site Supporter

Registered: January, 2014
Location: Sth Gippsland Victoria Australia
Posts: 4,255

1 user found this helpful
Lens Review Date: April 25, 2015 I can recommend this lens: Yes | Price: $360.00 | Rating: 7 

Pros: Good IQ when used within limitations, light weight, well constructed, useful zoom range, fun to use
Cons: Low contrast, dull colours, mediocre sharpness with distant subjects, vignetting, requires good light
Sharpness: 7    Aberrations: 7    Bokeh: 6    Handling: 8    Value: 8    Camera Used: K-30    Autofocus: 7   

I bought this lens in 2013 as an affordable way to 500mm with AF, mainly for birds and wildlife shots. It is much lighter and was much cheaper than the alternatives. I have since replaced it with a long prime, but it was a lot of fun while I had it.

Construction of the lens is good. My copy showed no zoom creep at all, and no wobble in the barrel. The positioning and operation of the zoom ring and focus ring can take some getting used to but are smooth to operate.

There is a learning curve with a long lens like this. It is light enough (about 1.3kg) to use handheld even at 500mm, but this requires good technique and a fast shutter speed (at least 1/500th sec, preferably faster). A solid tripod is recommended, whenever practical; if not, try a monopod.

Maximum aperture is a useful f5.6 up to about 320mm (comparable to the DA 55-300, which is f5.8 at 300mm); it then jumps to f6.3.

Like many screw-drive lenses, autofocus is noisy but not slow. Of course with a maximum aperture of f6.3 at the long end, AF can struggle if the light is poor. The lack of a focus limiter and manual focus override doesn't help.

Sharpness at the long end improves when the lens is stopped down to f8 or so. When coupled with a fast shutter speed, this obviously requires high ISO, good natural light or a flash.

Used within its limitations, the lens can produce good images - I got best results in good light when the subject was not too distant. Even then, PP was required to improve colour and contrast and remove vignetting. Here's a before-and-after example (#1 is straight conversion of RAW file with no processing; #2 is after a quick spin in DxO Optics Pro (probably overdid the ClearView a bit!).

Samples posted here:
New Member

Registered: January, 2011
Location: Livermore, CA
Posts: 1
Lens Review Date: February 19, 2014 I can recommend this lens: Yes | Price: $300.00 | Rating: 8 

Pros: Value for money, Sharp closed down
Cons: Zoom creep, Zoom Handling, CA/PF
Sharpness: 8    Aberrations: 7    Bokeh: 7    Handling: 7    Value: 9    Camera Used: K5 IIs   

I find this a great bargain lens for reach in good light. As others have said before, the lens is best used stopped down and with a sturdy tripod. Preferably also with a cable or IR remote. The lens is subject to vibration when fully extended, even with sturdy tripods and sometimes I felt even a 2 second delay would not be enough to damp them.

Above about f8 it gives great results, a few images below (all shot on tripod, cable release)

It does show CA/PF, again stopping down will resolve some what.

Given a chance I would definitely pay the big bucks and get a top tier long tele-zoom but for the price, this gives good results with the right settings and light.

Veteran Member

Registered: October, 2008
Location: Japan
Posts: 1,122

1 user found this helpful
Lens Review Date: October 16, 2012 I can recommend this lens: Yes | Price: $444.00 | Rating: 8 

Sharpness: 8    Aberrations: 8    Bokeh: 8    Handling: 7    Value: 9   

For years, my longest zoom has been the FA100-300/4.7-5.8.
A good lens, but was often found wanting in length for bird photography.

I needed something longer to get the shots I couldn't manage with the FA lens.
My search brought me to the reviews and even more internet searches of this lens.
I checked photos on Pentax Forums, and also searched the web and saw a lot of good photos from Canon and Nikon mounts as well as here.

I paid 35,000yen for this lens (276 pounds).
Whilst being affordable, it was still a lot of money for me and took a while to save up.
Other choices were all Sigma offerings, such as the 50-500 and 150-500.
These two lenses were a lot more though, meaning I would probably need another 6 months to save up the extra.
I gambled and bought the 170-500.

First impressions, it is indeed a big lens, and even bigger when fully extended, but it's not too heavy.
Hand-held shots are possible and Pentax's SR works well.
The lens feel nice and solid, and the focusing ring is rubberised.
It takes 86mm filters.
You have to get used to the weight and balance, especially when fully extended.
There is a bit of a learning curve going from a FA100-300, which is all plastic and very light, to this behemoth.
Still, I look on it that it's another skill I have to acquire.

I have mounted it on a Manfrotto MT294A3 with Manfrotto 804RC2 pan head.
This is a sturdy set-up and works well.

With my K-5, AF is generally snappy.
I noticed a few saying that it hunts, but I think the K-5 certainly helps AF.
It's not as noisy as I expected, as others are also saying.
So, these two "issues" are not a problem, at least not a major one.
Remember that I'm comparing these two points with my FA100-300, which is incredibly noisy and also hunts on occasions.

As for sharpness, well I think it's far from perfect wide open, but generally good for such a lens.
I have stopped down to F8 or F10 and there is improvement.
It also seems to depend how close your subject actually is.
It is a bit soft at 500, but stopping down helps, and I feel comfortable using ISO 1600 with my K-5, so I have no major disappointments.
I'm now able to get the shots I need from 300-500, so I'm pleased with the results overall.

I haven't experienced the zoom creep issue that's been reported.
However, the zoom isn't smooth, and can be a touch jerky at times.
The hood is also very loose, so I might need to get another one sooner or later.

I recommend this lens to people on a budget, like myself, or perhaps even photographers staring out and who are curious about bird photography and don't want to invest too much.
The re-sell value should remain similar, should one decide to sell it.

Bear in mind, there is a huge difference using this lens compared to a 70-300-100-300.
You'll need to get used to the balance when holding it, and also become familiar with the camera settings to get the best results possible.
With practise, this is a good lens at an affordable price.

Photos below were edited in Picasa.
Seem to have lost a bit of overall quality after uploading.

Considering the price, size, build, and overall quality of photos, I'd like to give it 8.5 overall.

Site Supporter

Registered: August, 2010
Location: Centurion, South Africa
Posts: 376
Lens Review Date: July 4, 2011 I can recommend this lens: Yes | Price: $550.00 | Rating: 7 

Pros: Value for money. Sharp image from 170-450
Cons: Slow AF. Weak image quality from 450-500

Anyone with a limited budged often starts of with a Sigma 170-500.
It is a jack of all trade & value for money zoom lens. I have had this lens for close to
8 years now and it only has been a pleasure. The worst I supposed is the poor f-stop from 250mm upwards, but there are means of ways (ISO Settings etc) to make up for that. But, I mostly take pics in good light conditions in anyway, doing Wildlife & Bird photography mostly. I have upgraded to the new BIGMA 50-500 HSM OS lens now, but I will still keep the old workhorse.
Site Supporter

Registered: November, 2010
Location: California
Posts: 2,223
Lens Review Date: February 20, 2011 I can recommend this lens: Yes | Price: $600.00 | Rating: 10 

Pros: Great IQ from 170 to 500mm, AF, sharp, great price
Cons: None so far - I wish it had quick focus to to switch from AF to manual.

Every single book I read about shooting with zooms and every professional seminar I have attended confirmed that zooms beyond 200 mm MUST be used with a good not only sturdy by heavy tripod (This lens needs as a minimum, a Manfrotto 055XPROB Pro Tripod Legs +Manfrotto 498RC2 Ball Head with Quick Release) if you want professional looking good quality photographs. I have noticed that many reviewers talk about a lens being soft at certain focal distances, but what I have experienced in similar occasions, is that if I use a good tripod, my photos come always sharp. That is how I get the best of every lens, zoom or not. When I must hand hold the zoom, I try to increase the shutter speed to a number higher or equal to the focal length for acceptable shots (that means a higher ISO or more grain, or noise). I read that a photographer must marry his/her tripod for nature/wildlife shots.

I gave 10 to this lens because there is no 9.5. The only negative aspect that I have seen in this lens is that when AF to the moon at about 90 degrees (almost vertical), the camera screw has a hard time getting it to focus. It is too heavy for the Pentax screw. Adding an SDM would have helped on that. The creeping that happens in mostly all big zooms is fine, you can control it when you get more experience.

This lens is heavy and it should be used with a heavy tripod (as one should with all zooms larger than 200mm). However, it is light enough for a normal-to-strong person to hand hold it for shooting birds. It takes a good technique to shoot a zoom hand-held. I happened to be an ex-sharp shooter, so I know how to minimize the shaking. Even then, you will notice some softness in the hand-held shots. On the tripod, I use it with remote control shooting.

I found this lens beautiful and fascinating and pretty much it is the only one I use, I have put to the side my faithful FA 100-300mm f4.7(metallic looking) zoom. The image quality is excellent in every focal distance, including 500mm. I have used it with a 1.7x AF converter and a heavy tripod and still get acceptable pictures. However, it is asking too much. When using a 1.7x or 2X converter, you are stopping down 2 f-stops making it slow. So, I do not recommend you using those converters. If you have a 1.4x AF converter and a sturdy heavy tripod, that will work. Again, a good tripod and remote shooting is a must.

This lens is impressive and it extends very long making the need for a tripod even greater. If you just want a zoom, made of light plastic, that Auto-Focus for you and gives you sharp pictures at 500mm when you are riding on a bike and having a beer, etc, this is not your lens. Good luck finding it. I recommend this lens if you are serious about becoming a nature/environmental photographer because to become that you need patience and will have to use a tripod. Do not buy this lens if you are not going to buy a good sturdy heavy tripod with a good head. I wish this lens had QUICK SHIFT FOCUS, to allow for focussing manually while in AF, like the new Pentax kit lenses.

If you are serious about becoming a professional, or serious nature amateur photographer, buy this lens. It is the cheaper alternative to buying the Bigma (about $1,500 -- the Sigma 50-50mm). I will post some handheld pics taken with my lens for your viewing pleasure.


Veteran Member

Registered: July, 2007
Location: Hong Kong
Posts: 431

6 users found this helpful
Lens Review Date: October 21, 2010 I can recommend this lens: Yes | Price: None indicated | Rating: 8 

Pros: Sharp, light weight and fast AF.
Cons: Zoom creep.

A very good option for Pentax user to use this lens for widelife, especially the price not too expensive. A very sharp lens from f8 to f11. I can ever get very sharp images for handheld. If people are saying this lens not sharp, may be they have back/front focus issues betwwen the lens and camera, or their skills are still not adequate enough to handle a 500mm lens. However, this is still a budget lens in the tele class, so do not expect the contrast and colors are great enough to be compared to those excellent 500mm/600mm primes. Nevertheless, this lens is really a good start for you to enter into the widelife photography.

My samples of the lens :


Registered: January, 2009
Posts: 9,674
Lens Review Date: April 20, 2010 I can recommend this lens: Yes | Price: $275.00 | Rating: 7 

Pros: Nice long zoom
Cons: stop down for good images to f8 at least

I bought this lens recently nwe from what is old stock. Its my first lens over 200mm and I love to use it. It needs to be stopped down for scharp images and I use it at f9 normally. So only at sunny days for me. There are pretty nice things possible for me, so it's a nice and cheap lens.

[YT][/YT] filmed at 500mm with the K-7
Senior Member

Registered: November, 2008
Location: Lismore, NSW, Australia
Posts: 145
Lens Review Date: November 11, 2008 I can recommend this lens: Yes | Price: None indicated | Rating: 8 

Pros: Focal range
Cons: Zoom creep

I actually bought this lens before I bought my camera. Looking solely for zoom range I found one for sale second hand with a x2 TC and two filters for $600 the lot after I googled it and was directed to an astronomy web forum.

I agree that the lens does not have a smooth zoom action and the quality is not the the best but it has definitely given me plenty of value for money. For the rally photography I do, it has been great and produced some good shots.
Lens Review Date: July 19, 2008 I can recommend this lens: No | Price: $1,000.00 | Rating: 6 

Pros: focal range, price
Cons: too soft

I choose this lens because I wanted to get some experience with bird photography. In the 8 months that I now own this lens I can only say that the results are disappointing enough to start looking for an alternative, even though the price for something with comparable focal length will probably go through the roof. With my K100D Super and at 500mm maybe 1 out of 10 pictures is sharp, even when shutter times are in the 1/300 or shorter range and when using a tripod. On a forum I found somewhere that this lens really softens above 400mm, so now I try to not go above that to see if that improves sharpness.

I can confirm that there is indeed something wrong with the diaphragma range, at 500mm I cannot go below 6.7.
Veteran Member

Registered: July, 2007
Location: North West UK
Posts: 382
Lens Review Date: June 2, 2008 I can recommend this lens: Yes | Price: $600.00 | Rating: 8 

Pros: Range, fairly light considering the range. Cheap for the range. Works best at F8 onwards
Cons: Soft wide open, need to work with it. very noisy AF

I have had this lens now for 9 months so I thought I better put a review on.

I have used it many times, mainly for Nature. Initially with photographing Seals, I thought it was okay, A little soft, but with PS you can sharpen accordingly. However with further use, I have found this lens wanting.

On the whole, the sharpness is not there, no matter how wide or how zoomed in you are. Occasionally you might hit the jackpot, but that is a rare occasion.

On the up side the CA is minimal, and it can be fun to use, if only after many shots you get a good one. (not good if you fill your card up with rubbish. but hey, if you have 4gb to go, you might be lucky)

Another interesting thing is that it states the wide F-stops as F5-F6.3, but with mine I get F4.5-F6.7 on the K10D! Very strange.....

On the whole It can be fun, if your expectations are not high, but, and this is a but, Don't buy this lens new, as it is not worth it, save up for the Bigma, but like me buy second hand and play, then sell it and buy the Bigma.

I now have a second hand Lens to sell, in excellent condition, so I can fund a Bigma.

Edit (Jan 2011)
I still have this lens and I have used it more, so I thought I would update the review.
Firstly you really need to work with this lens to get the best out of it. However, once you have worked out how to get the best out of it, then it is a bit of a bargain.
You do need a good tripod to ensure sharp images, although you can use it hand held, images without a tripod will be hit an miss, sometimes it will nail it, sometimes not.
Also, best to use it at at least F8 for have a great chance of sharpness and still decent blurred background. Also, I find that using the TAv mode on my K10D or K20D works wonders with this lens - Set it at F8-F11, 1/100sec and you are away.
Bokeh is okay, not the best, but not the worst. It is reasonably smooth.
Even at 500mm it okay, a tad soft, but a little bit of unsharp mask in PS brings the images to life.
Was it worth the 300 I paid for it second hand? Yes no doubt about it, now I know how to get the best from the lens.
However, as you can no longer get this lens new, I believe the 150-500 is far better, but if you can find the 170-500 for around the price that I paid and can't stretch to the 150, or the mk2 Bigma, then it is worth getting one.

I have changed the rating from a 5 to an 8, because of the price I paid. If I had bought new, it would have been a 7.
Veteran Member

Registered: September, 2006
Location: North Idaho
Posts: 665
Lens Review Date: April 9, 2008 I can recommend this lens: Yes | Price: None indicated | Rating: 6 

Pros: focal range
Cons: "top heavy" when fully extended - not a smooth zoom mechanism

I owned this lens for awhile . . . and have since sold it. It was purchased used from Adorama and there were no negative issues with it. The lens was in great condition. Whoever owned it before me took pretty good care of it. I was able to sell it because I had other, better lenses that cover the focal range. The reason I sold it was due to the negatives.

1. This lens extends in physical size when zooming to the longer focal lengths. Even though it has an excellent tripod mount, the "rig" is unstable when fully extended.

2. The zoom mechanics are not smooth. Meaning, that when one zooms from a shorter focal length to a longer, turning the zoom ring is not a smooth operation. There are several places that there is a little catch and you have to exert more or less pressure to zoom. I suppose this would not be an issue if you went directly to the focal length you desire, but I normally like to "slow zoom" and watch through the viewfinder as I zoom. It is difficult to do so with this lens.

Many of the forums mention that images created with this lens are "soft" at the longer focal lengths. In my experience, the images were just fine. Maybe my standards are not as high as other, but I didn't see any "problems" with my images at the longer focal lengths.

I'll give a qualified "yes" recommendation. It has a great focal range in focal lengths where there are vast shortcoming for Pentax users. For a "consumer zoom" it is very good, but mechanically and optically, it cannot measure up to my Sigma EX super-zooms (70-200/2.8 and 100-300/4). Then again, it doesn't pretend to be an EX lens.
Add Review of Sigma 170-500mm F5-6.3 APO

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