Pixalo Photography Community

Go Back   Pixalo Photography Community > Photography Forums > Cameras, Lenses and Accessories

Cameras, Lenses and Accessories: Discuss Lens test: Sigma 18-50mm F2.8 Vs kit lens...My Sigma 18-50mm F2.8 EX DC arrived today and what better way to break it in than by pitching it ...
Welcome to the Pixalo Photography Community. As a Guest you are free to browse the site, but see what extras you get as a Member here.


Reply
 
LinkBack Thread Tools Display Modes
Old 02-11-2005, 17:01   #1 (permalink)
Forum Regular
 
fingerz's Avatar
 
Join Date: Jul 2005
Posts: 790
fingerz is on a distinguished roadfingerz is on a distinguished road
User's Gallery
Lens test: Sigma 18-50mm F2.8 Vs kit lens

My Sigma 18-50mm F2.8 EX DC arrived today and what better way to break it in than by pitching it in a head-to-head battle with the kit lens. I had intended to set the tripod up near a window and shoot stuff outside but it was windy and rainy so I decided to shoot indoor stuff instead. Not ideal but hopefully I'll be able to do an outdoor test at some point.

This is the whole frame I used. The two little squares denote the sections used for the 100% crops in the two comparison images (middle and edge).




Method - camera
This test was done at 50mm. I haven't tested the 18mm end of the scale yet but I'll probably do that when I get a chance to do an outdoor test. My method was as follows. I set the camera up level on the tripod and locked it off. I used the Sigma lens first because I knew that its full zoom was exactly 50mm. Sadly the kit lens doesn't have a marking on the barrel to denote 50mm so I had to guess it as best I could. In the end (according to the Exif data) I think it was about 47mm. I set the white balance to indoor so all shots would have the same colour cast. I autofocused on the same point for both lenses (the adidas symbol at the top of the 'middle' box in the pic above). I shot in manual mode and noted down the shutter speeds for each aperture. I then used the same set of aperture/shutter settings on the kit lens, even though (oddly) the camera thought those settings were exactly one stop brighter than it did with the Sigma lens. The shots all came out looking exactly as bright as each other so I'm not sure why it thought the settings were too bright for the kit lens. It's worth mentioning that I didn't use the Sigma's lens hood as I didn't have one for the kit lens and I didn't use any UV filters, just so it was as fair as possible.

Method - processing
Once I had the shots I did nothing to them at all in RawShooter apart from convert them all to Tiff files. In photoshop I just took the 100% crops I needed and applied the same small amount of unsharp mask uniformly to all the images. I applied the sharpening because when I did the comparison between the 16-35L and the kit lens it was much easier to see the differences after sharpening was added.

Results
You can see the results here. I'm using text links because the final comparison images are pretty big. They're about half a meg each:

Middle of the frame:
http://www.jameyhoward.com/filebucke...kit_middle.jpg

Edge of the frame:
http://www.jameyhoward.com/filebucke...gvkit_edge.jpg

Conclusion
My conclusions are that the Sigma is either sharper or at least as sharp as the kit lens at all apertures where they compete. However, when the Sigma gets to f/3.5 and wider it starts to get quite noticably soft at the edges of the frame. Whether this is due to shallow depth of field I'm not experienced enough to say. The middle of the frame in the f/2.8 shots doesn't look too bad to me. The shadow contrast looks about equal between the two lenses. The Sigma's sweet spot seems to be a bit wider, at around f/5.6 compared to around f/8 on the kit lens. Although the edge of frame results for the Sigma look slightly sharper at f/8.

Overall I'm quite happy with my purchase. I think it will fill the gap nicely until I get a job/eye that requires something with an 'L' on the end. One slightly annoying thing is that the Sigma's lens hood doesn't allow you to get your fingers far enough in to remove/replace the lens cap (or turn a polariser). So you've either got to remove the hood to fiddle with your filter and take off the lens cover or just walk around all day with the lens cap off (which I tend to do anyway) and the polariser set how you want it.

Edit - reading this back it sounds like I've made my mind up and I'm just posting this for information, which isn't the case. I'd value feedback from you lot on what you think of the comparisons etc. Cheers. Sorry. Cheers.

Last edited by fingerz; 02-11-2005 at 22:22.
fingerz is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 17:24   #2 (permalink)
Forum Regular
 
fingerz's Avatar
 
Join Date: Jul 2005
Posts: 790
fingerz is on a distinguished roadfingerz is on a distinguished road
User's Gallery
Just went to try the Hoya 67mm circular polarising filter I got at the same time. Screwing it onto the front of the lens. Little metal ring pops out of the filter, followed by the polarising glass.

Lovely bit of craftsmanship there. I've managed to get it all back in and given it a quick shake to make sure. Not the best start though.
fingerz is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 17:52   #3 (permalink)
DavidUK
Guest
 
Posts: n/a
User's Gallery
Quote:
Originally Posted by fingerz
Just went to try the Hoya 67mm circular polarising filter I got at the same time. Screwing it onto the front of the lens. Little metal ring pops out of the filter, followed by the polarising glass.

Lovely bit of craftsmanship there. I've managed to get it all back in and given it a quick shake to make sure. Not the best start though.
..not just me then! that happened on both my Hoya Skylight 1B and Circular Polariser, in fact they were both like that out of the case from new, one edge of the metal ring having popped out of the filter housing
 
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 18:06   #4 (permalink)
Pixalo Crew
 
Join Date: Jan 2005
Posts: 19,252
Steve is just really nice
Steve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really nice

Image edit - ASK
User's Gallery
Users Camera Equipment List
Nice write up Jamey..so F5.6 through to and incl F16 all look better on the Sigma from your pics of the centre of the frame and at the edge all the way through to F22. It also shows how bad the Canon kit lens is at the edge in general, although you have to say that for a low value starter lens it does produce reasonable results that most would never question.
Steve is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 18:15   #5 (permalink)
Forum Regular
 
fingerz's Avatar
 
Join Date: Jul 2005
Posts: 790
fingerz is on a distinguished roadfingerz is on a distinguished road
User's Gallery
Yeah for 50 (or so) extra the kit lens has to be worthwhile but I'm happy to be moving up a rung. Even if it is only one rung.
fingerz is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 18:27   #6 (permalink)
Pixalo Crew
 
Join Date: Jan 2005
Posts: 19,252
Steve is just really nice
Steve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really nice

Image edit - ASK
User's Gallery
Users Camera Equipment List
It may only be one step up in your opinion but you are also gaining a faster lens which I would guess is essential for the type of photography that you are most interested in.
Steve is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 18:35   #7 (permalink)
Forum Regular
 
RobertP's Avatar
 
Join Date: Sep 2005
Location: Woodford Essex
Posts: 838
RobertP is on a distinguished roadRobertP is on a distinguished road

Image editing O.K.
User's Gallery
I guess I could do the same thing with my Tamron 28-75.

I do have a problem though....

Where am I going to find that many shoe boxes



Your test confirms what I always thought about the kit lens - it is not as bad as people make out. I bought the Tamron as much for the constant f2.8 as any other reason.
RobertP is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 18:37   #8 (permalink)
Getting Comfy
 
Mr THX's Avatar
 
Join Date: Sep 2005
Location: Barnsley
Posts: 177
Mr THX is on a distinguished roadMr THX is on a distinguished road

Image editing O.K.
User's Gallery
Quote:
Originally Posted by Steve
It may only be one step up in your opinion but you are also gaining a faster lens which I would guess is essential for the type of photography that you are most interested in.
Sorry Steve what do you mean by faster ??

Thanks
Mr THX is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 18:52   #9 (permalink)
Pixalo Crew
 
Join Date: Jan 2005
Posts: 19,252
Steve is just really nice
Steve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really nice

Image edit - ASK
User's Gallery
Users Camera Equipment List
Quote:
Originally Posted by RobertP
I guess I could do the same thing with my Tamron 28-75.

I bought the Tamron as much for the constant f2.8 as any other reason.
I also own the Tamron and like many Sigmas if you get a good one its bloody great. The constant F2.8 is also very nice, especially for throwing out backgrounds at 75mm.
Steve is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 18:54   #10 (permalink)
Pixalo Crew
 
Join Date: Jan 2005
Posts: 19,252
Steve is just really nice
Steve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really niceSteve is just really nice

Image edit - ASK
User's Gallery
Users Camera Equipment List
Quote:
Originally Posted by Mr THX
Sorry Steve what do you mean by faster ??

Thanks
Sorry...by faster I mean a lower F stop..which in turns means that the lens will let in more light allowing the camera to use faster shutter speeds at the same ISO settings. Good for action or low light shooting. The sigma is capable of using lower F stops than the Canon kit lens and so is said to be "faster"

Hope that helps.
Steve is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 19:00   #11 (permalink)
Forum Regular
 
RobertP's Avatar
 
Join Date: Sep 2005
Location: Woodford Essex
Posts: 838
RobertP is on a distinguished roadRobertP is on a distinguished road

Image editing O.K.
User's Gallery
Well I typed this while Steve was posting so here my assisted effort.

The F stop number tells you how big the 'Aperture' is. A 50mm f1.0 lens would have an objective lens 50mm diameter so the ratio of focal length/aperture diameter is 1.

A lens which can only do f5.6 at 50mm focal length would have a hole for the light 50/5.6 = 8.9mm diameter.

So faster = bigger diameter... lower f stop figure
RobertP is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 20:11   #12 (permalink)
Member
 
Join Date: Jan 2005
Location: kings hill
Posts: 4,636
Matty is an unknown quantity at this point

Image editing O.K.
User's Gallery
so the 2 of you with the Tamron, im in for one of these, worth the money?
Matty is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 20:14   #13 (permalink)
Forum Regular
 
fingerz's Avatar
 
Join Date: Jul 2005
Posts: 790
fingerz is on a distinguished roadfingerz is on a distinguished road
User's Gallery
RobertP - yeah I agree about the kit lens. I never thought it was that bad tbh. Certainly not for the price, anyway. And the constant f/2.8 was also one of my main concerns. Although having a non-rotating front end is very nice. Pity it's nearly impossible to use the CPF and the lens hood at the same time but I guess it's always going to be fiddly, at best.
fingerz is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 20:36   #14 (permalink)
Forum Regular
 
RobertP's Avatar
 
Join Date: Sep 2005
Location: Woodford Essex
Posts: 838
RobertP is on a distinguished roadRobertP is on a distinguished road

Image editing O.K.
User's Gallery
Quote:
Originally Posted by EosD
so the 2 of you with the Tamron, im in for one of these, worth the money?
I'd say so. It is on my camera most of the time and I feel pretty confident of the results I get using it. Feels solid.

You can leave the hood on and easily fit/remove the lens cap due to the novel design of the latches. no problem with filters either.

For dropping the camera back in the Crumpler bag (lift flap drop it in type - easy access) the hood takes only a second to rotate off turn over and refit reversed.

If do ever get round to testing it, it may be softer wide open but I don't notice it and would not hesitate to use it at f2.8

Minuses -

You certainly know you are carrying it! Way heavier than the kit lens.
If you don't use the zoom latch it will drop to full zoom under gravity if you point it down. (does no harm)
Some say the AF motor is noisy - you can hear it but not a prob to me.


Just occaisionally I could do with a bit more width. The range of the Sigma may be more flexible.
I intend to keep the Tamron and maybe get a Tokina 12-24 for scenery etc.
__________________
20D. Kit lens. Canon 50mm 1.4. Sigma 150mm 2.8 macro. Tamron 28-75 XR Di. Canon 70-200 f4L . Canon 100-400L. 580EX.
RobertP is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 20:42   #15 (permalink)
Member
 
Join Date: Jan 2005
Location: kings hill
Posts: 4,636
Matty is an unknown quantity at this point

Image editing O.K.
User's Gallery
thats a good write up too Fingerz, wanna do a review?
Matty is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 20:44   #16 (permalink)
Member
 
Join Date: Jan 2005
Location: kings hill
Posts: 4,636
Matty is an unknown quantity at this point

Image editing O.K.
User's Gallery
Thanks Robert, i know Steve is happy with his, some top shots hes got from it, i think i will try and find one locally to play with then make a purchase!
Matty is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 20:51   #17 (permalink)
Getting Comfy
 
Mr THX's Avatar
 
Join Date: Sep 2005
Location: Barnsley
Posts: 177
Mr THX is on a distinguished roadMr THX is on a distinguished road

Image editing O.K.
User's Gallery
Steve / Robert

Thanks for that, understood the lower F stop - it was the 'faster' remark that caught me out - I'll catch up with all this lingo before long.

Again thanks
Mr THX is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 20:59   #18 (permalink)
Forum Regular
 
RobertP's Avatar
 
Join Date: Sep 2005
Location: Woodford Essex
Posts: 838
RobertP is on a distinguished roadRobertP is on a distinguished road

Image editing O.K.
User's Gallery
'faster' shutter speeds for the same shot with a large aperture....
RobertP is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 21:02   #19 (permalink)
Forum Regular
 
fingerz's Avatar
 
Join Date: Jul 2005
Posts: 790
fingerz is on a distinguished roadfingerz is on a distinguished road
User's Gallery
Quote:
Originally Posted by RobertP
...the hood takes only a second to rotate off turn over and refit reversed.
Heh. Would you look at that. You can reverse the hood. Neat.

/hood novice


Quote:
Originally Posted by EosD
thats a good write up too Fingerz, wanna do a review?
Feel free to lift/move this as you see fit.
fingerz is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 21:08   #20 (permalink)
Forum Regular
 
RobertP's Avatar
 
Join Date: Sep 2005
Location: Woodford Essex
Posts: 838
RobertP is on a distinguished roadRobertP is on a distinguished road

Image editing O.K.
User's Gallery
The canon hoods seem less tolerant when you do that - the Tamron you can just spin it off and slap it back on without thinking...canon ones seem to need a bit more lining up or they bind a bit.
RobertP is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 21:16   #21 (permalink)
Forum Regular
 
fingerz's Avatar
 
Join Date: Jul 2005
Posts: 790
fingerz is on a distinguished roadfingerz is on a distinguished road
User's Gallery
The Sigma one went on fine backwards, but the petals are at about 45 degrees to where they'd normally be. Dunno why.
fingerz is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 02-11-2005, 21:58   #22 (permalink)
Forum Regular
 
milou's Avatar
 
Join Date: Apr 2005
Location: Southampton
Posts: 583
milou is an unknown quantity at this point

Image editing O.K.
User's Gallery
Aye, nice write up there you old pro
milou is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 03-11-2005, 04:14   #23 (permalink)
Retired Crew
 
Sonsey's Avatar
 
Join Date: Oct 2005
Location: N. Ireland
Posts: 7,479
Sonsey is a jewel in the rough
Sonsey is a jewel in the roughSonsey is a jewel in the roughSonsey is a jewel in the roughSonsey is a jewel in the roughSonsey is a jewel in the roughSonsey is a jewel in the roughSonsey is a jewel in the rough

Image editing O.K.
User's Gallery
Users Camera Equipment List
Quote:
Originally Posted by EosD
so the 2 of you with the Tamron, im in for one of these, worth the money?
I'll add my voice to that... definately worth the money.

I find it quite light, especially compaired to the Canon and Sigma models. The new Sigma 24-70 EX apparently comes close to it for picture quality + has a bit better build quality and an extra 4mm at the wide end (but you lose 5mm at the long end).

As Robert has said, it is a bit noisey when focusing but not excessively so, and if you like your landscapes then you'll probably be looking to add a wider lens to the collection aswell sometime in the future (or just use you kit lens)... but as a walkabout lens it's hard to beat, very sharp, good contrast, thumbs up
__________________
Regards,
Iain.

Last edited by Sonsey; 03-11-2005 at 04:22.
Sonsey is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
WTB: CANON EF 50mm f/1.8 Mk 1 lens anne Photography Classified Adverts 2 29-07-2007 11:25
i-TTL with Nikon 50mm f1.8 lens Catdaddy Cameras, Lenses and Accessories 4 06-12-2005 10:27
Canon 50mm lens Matty Cameras, Lenses and Accessories 37 28-09-2005 20:50
Canon 50mm F1.8 lens for just 17 Steve Suppliers, Shopping and Bargains 18 01-05-2005 23:17
Canon 50mm 1.4 USM Lens CT Cameras, Lenses and Accessories 8 11-04-2005 10:30


All times are GMT +1. The time now is 15:52.


vBulletin Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
ReviewPost & PhotoPost vB3 Enhanced, Copyright 2003-2014 All Enthusiast, Inc.
SEO by vBSEO 3.3.0
Copyright 2006 - 2017 Pixalo.com

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197