Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
01-05-2011, 11:27 AM   #1

Lens help! Sigma vs Pentax

Hi there,

I am new to DSLRs and lenses, so could someone explain what the main differences are between:

Sigma 70-300mm f4-5.6 Macro DG Lens
Pentax DAL 50-200mm

Does Sigma give better magnification/zoom?
Many thanks!

01-05-2011, 11:59 AM   #2
Inactive Account

Join Date: Aug 2008
Location: Michigan, USA
Photos: Gallery | Albums
Posts: 7,484
+100mm on the Sigma, 1:4 (I think) closeup capability on the Sigma, Metal mount, comes with a hood (I think), and if you're talking about the APO version of the Sigma, it's reported to handle things like chromatic aberration (CA) quite well.

The Pentax has the SMC coatings. Being a DA-L will lack quick shift, a hood, and has a plastic mount (compared to the Non L version). The Pentax is also smaller in size than the Sigma.

If you are considering a kit and looking for a longer range zoom, look at the DA (or DA-L) 55-300.

For what it's worth, I always found (when I had one) the 50-200 to be very limiting when I wanted a zoom. 200mm just never seemed enough for that type of lens. I now have primes for the 200-300 range (expensive) but that's another discussion.

Welcome aboard.

01-05-2011, 12:10 PM   #3

Hi JeffJS

Thanks so much for your reply!

The Pentax lens is the one included in the K-r twin lens kit. So I'm just wondering how much more zoom would Sigma give? How would you translate 100mm to magnification?

Sigma is also very affordable at 129 here in the UK. If that would allow me to both take macro AND if it has a longer range than Pentax, that could be good.

What do you think?
01-05-2011, 12:44 PM - 1 Like   #4
Veteran Member

Join Date: Dec 2008
Location: Roodepoort, South Africa
Photos: Gallery | Albums
Posts: 3,561
Macro officially means at least 1:1 magnification (so a subject of 10mm long will be 10mm long on the sensor). The DAL55-200 has a 0.24x maximum magnification so barely different from the Sigma.

Extra length does not automatically translate to more magnification because the minimum focusing distance comes into play. You get the biggest magnification at the closest focus distance. As an example, the DA18-55 allows a larger magnification (0.34x at distance 25cm) than the DA55-300 (0.28x at distance 140cm).

The main benefit of the Sigma is indeed the 100mm extra which makes it possible to get subjects that are far away larger in the photo. How much larger? 300/200 equals 1.5 times larger.

01-05-2011, 01:01 PM - 1 Like   #5
Inactive Account

Join Date: Aug 2008
Location: Michigan, USA
Photos: Gallery | Albums
Posts: 7,484
Look at it this way. These focal lengths are the focal lengths for 35mm film (or sensor in the case of full frame dSLR). 50mm is considered 'normal' in that format. In truth, normal for us is closer to 35mm (lens) but that's topic for different discussion. Here we'll just go with 50mm. The 50-200 will give 4x magnification if you want to think of it that way. The 70-300 will give you 6x (from 50mm).

I never had the Sigma but did have the Tamron (DI LD) version of the lens. It offered 1:2 macro and I would actually recommend it over the Sigma based on my own experience only.

The best way I can show the difference in magnification (macro range) is this..

This was taken at macro 300mm with the tamron.

From the same position, this was done at 180mm macro (with the tamron)

This is non macro at 300mm

You could take the same shot with the 200mm but it would be a wider shot and to get That framing, you would have to crop your photo.



What the 300mm buys you over 200mm is the ability to stay back. It does come at a cost though. The longer the zoom, the tighter the crop (you see in the viewfinder), the more difficult it is to hold things steady. Even with Shake reduction, you'll find yourself having to dial faster shutter speeds to get things held in place.

The Tamron can be had for about the same price or less as the sigma. I mentioned CA in my other post and due to lack of experience with the Sigma, cannot give a direct compare between the two lenses. The Tamron is notorious for CA and PF in high contrast situations. It can be corrected in post processing but it may be a deal breaker for you (the bird shot is a corrected one). I am also not 100% certain that the Sigma is 1:4 macro (and not something better like 1:2). There are 100s of threads here comparing the two lenses, each has it's fans and naysayers. Both would probably serve you well and if you can 86 the DA-L 50-200 and get one of the 70-300s instead for about the same money, I would go for that option.

Now, This is a decent way to go to get Macro on an all in one lens but to really do macro, you'll eventually find yourself wanting a dedicated macro lens which can be pretty expensive. There are other ways of doing it, a Raynox 150 or 250 that will fit your 18-55 is a recommended way to go around here. Those are basically magnifying glasses that fit on the front of the lens. I mention all that, because you mentioned Macro, and by most accounts, the Pentax DA-L 55-300 leaves both the sigma and tamron laying in the dust for image quality (just to confuse you more ).

I'm sure others will sound off but I'll leave it with my original statement. When I had the 50-200, 200mm was Never enough when I wanted Zoom.

01-05-2011, 05:16 PM   #6
Veteran Member
slip's Avatar

Join Date: Oct 2006
Location: 2 hours north of toronto ontario canada
Photos: Gallery | Albums
Posts: 3,537
I don't have either one of these lens but can comment on Sigma lenses.
I have a 17-70 2.8-4.5. It is really sharp when it is between f5.6 and f8, but it is soft wide open (2.8-4.5)

01-05-2011, 08:04 PM   #7
Veteran Member
KxBlaze's Avatar

Join Date: Feb 2010
Location: California
Photos: Gallery
Posts: 1,602
A lot of people compare the DA (and L) 55-300, Sigma 70-300 APO and the Tamron 70-300 XR Di-II, with each having an area in which they are better than the others. I think what was concluded was that the Pentax had better over all IQ, the Sigma controlled CA better and the Tamron was a bit sharper and had a 1:2 macro setting and was the cheapest. I personally have the Tamron because of the price point ($160 new), the 1:2 macro (Sigma is 1:4 and Pentax does not have Macro setting) and it has an aperture ring (needed for my 2x teleconverter.

Like another poster said the 50-200 doesn't seem like a very useful lens because 200mm just isn't long enough sometimes, whereas I find the 300mm focal length perfect most of the time.

It's all about personal preference but I suggest you look at other options besides the 50-200. If you want the Kr kit then definitely go with the 55-300, you won't regret it.

01-05-2011, 10:01 PM - 1 Like   #8
Veteran Member

Join Date: Dec 2009
Location: Ontario
Posts: 550
I personally own the sigma apo version. From my own research I believe that the sigma lens has better macro in terms of iq over the tamron. Overall iq the pentax is better at 300mm. But if you are comparing the 50-200 and the sigma or tamron I think I would get the pentax wr version over the others. The sigma is soft on the 300 mm end of the scope it does fine at everything below 200mm. The tamron has better image quality all around but suffers from ca and pf. If you can live with it then it will provide good sharpness. I would pick the wr version of the pentax as an upgrade investment if and when you get a k5. Weather resistant is a very nice feature to have.
01-06-2011, 08:17 AM - 1 Like   #9
reeftool's Avatar

Join Date: Dec 2007
Location: Upstate New York
Photos: Gallery | Albums
Posts: 9,210
I have the Sigma lens you mention and have had very good results. For the appox. $150 price new, I don't think there is a better buy out there although the similar priced Tamron has it's followers too. The macro/closeup mode is excellent. It works only in the 200-300mm range and is perfect for my uses which often is shooting from a kayak. The lens is at it's best between f8-f11. It's light enough to hand hold but best results will be with a tripod or monopod. There are better long zooms but they are going to cost a lot more. The Pentax DA 50-300 is also very good and better IQ at 300mm. It costs a little more and doesn't have the macro mode. I now have a M 300mm prime but the Sigma is staying in my bag. The macro mode is good enough to make it worth owning this lens for that feature alone.
01-06-2011, 09:23 AM - 1 Like   #10
audiobomber's Avatar

Join Date: May 2008
Location: Sudbury, Ontario
Photos: Albums
Posts: 6,803
Clipping a $50 Raynox DCR-150 macro adapter on the end of any of these telephotos will get you real 1:1 macro and beyond, with no significant loss in quality.
01-06-2011, 10:31 AM - 1 Like   #11
Site Supporter
Site Supporter
Ahab's Avatar

Join Date: Jul 2007
Location: Arnold, Md.
Photos: Gallery | Albums
Posts: 762
To all those folks who talk about the notorious CA and PF of the Tamron 70-300 Di-II, Please show me. I've posted images which were taken with my version under the supposed conditions which it occurs with no observable CA and PF and no PP.
01-06-2011, 10:37 AM   #12
Inactive Account

Join Date: Aug 2008
Location: Michigan, USA
Photos: Gallery | Albums
Posts: 7,484
QuoteOriginally posted by Ahab Quote
To all those folks who talk about the notorious CA and PF of the Tamron 70-300 Di-II, Please show me. I've posted images which were taken with my version under the supposed conditions which it occurs with no observable CA and PF and no PP.

The Uncorrected photo from above (shot wide open).

01-06-2011, 01:17 PM   #13

Wow - Thank SO much to everyone for your kind input, much appreciated. I'm just thinking if it's better getting the K-r twin lens kit which includes DAL 18-55mm/DAL 50-200mm or the single lens kit which just includes 18-55mm and then buy Sigma 70-300mm separately? What would you do?

Thanks so much!
01-06-2011, 01:28 PM   #14
Site Supporter
Site Supporter
K(s)evin's Avatar

Join Date: Sep 2010
Location: Colorado
Posts: 389
From what I've read, it appears the concensus is the one lens kit with the SigRon 70-300.
01-06-2011, 01:50 PM   #15
audiobomber's Avatar

Join Date: May 2008
Location: Sudbury, Ontario
Photos: Albums
Posts: 6,803
At the price mentioned, I suspect you're talking about the non-APO version of the Sigma 70-300. If so, you'll be dealing with significant purple fringing and softness at the long end. I doubt that anyone familiar with these lenses would vote for the non-APO Sigma. The best value IMO if you want the 300mm range is to the get the two lens kit with DA L 55-300mm.

I own a DA 55-300mm and a Tamron 70-300mm Di. The 55-70mm range is more important to me by far than pseudo-macro. None of these lenses have quick-shift. The plastic mount won't be a problem with a modicum of care. A plastic lens hood is available on ebay for about $14. Most importantly the 55-300 has the best IQ of all the lenses being discussed in this thread. There's plenty of evidence for that if you do a search. (PS My copy of the 55-300 is very slightly sharper than my copy of the Tamron, but colour and contrast with the Pentax is way better).

Last edited by audiobomber; 01-06-2011 at 02:00 PM.

  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, lens, pentax, pentax help, photography, sigma
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: Pentax k-2000 + kit lens (18-55) + sigma zoom lens 70-300mm dexmus Sold Items 6 11-09-2009 05:25 PM
For Sale - Sold: Pentax Lens Blowout; 50mm 1.4, Sigma 10-20mm, Sigma 400mm, etc. nufenstein Sold Items 13 03-30-2009 12:00 PM
For Sale - Sold: For Sale Pentax AF-540FGZ Flash, Sigma 28-70mm F2.8 DG EX AF Lens and a Pentax davidd10 Sold Items 11 12-07-2008 07:57 PM
For Sale - Sold: Pentax DA 18-55 kit lens, Pentax F 70-210, Sigma 70-300 waqas Sold Items 7 12-09-2006 11:55 PM

All times are GMT -7. The time now is 06:21 PM. | See also:, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]