Head to Head

[DonSchap]

Since we are both kind of new with these lenses, once I finally get my Tamron SP AF28-105mm f/2.8 LD mounted on my EOS 20D... I'd like to go "head-to-head" with Karin's Canon EF 28-105mm f/3.5-4.5 USM II (when she receives it) and see what we can do here.

I realize the aperture maximum is slightly different, but I will manually limit mine to match. I'm more interested in seeing how the 30D shoots at the different focal lengths, compared to the 20D.

Being a third-party lens, the Tamron lens should be close to the Canon lens, all things considered.

Spec wise, lets take a quick look, eh?
Canon
15 elements / 12 groups - Closest focus: 19.2 in. - Diag. Ang. View: 75 - 23 30'

Tamron
15 elements / 13 groups - Closest focus: 19.7 in. - Diag. Ang. View: 75 - 24

Terms:

We pick a neutral and MUTUAL subject... no horses or other rare objects... and fire off a progressive series of focal lengths (28, 35, 50, 75, 90 & 105)... maximum aperture (3.5-4.5 depending on focal length selected). Lighting is important, so I suggest a bright, sunny day (we can hope).... rather than some arbitrary lighting condition. This will limit the DOF for 'focus accuracy' and use the higher-end speed and lower ISO of the cameras.

In essense, a PHOTGRAPHIC duel, ACROSS THE POND! :eek:

I don't know, it just came to me. :confused: Sounded like fun. :D Any support from the viewing public out there? Karin... you game? :cool:

[coldrain]

Oh no!!! please don't do it, Karin... before you know it I will be bugged to compare my Tokina to his 11-18mm Tamron and my 18-50 Sigma to whatever he will throw at it! EEEK!!!:eek: :eek:

[cdifoto]

Oh no!!! please don't do it, Karin... before you know it I will be bugged to compare my Tokina to his 11-18mm Tamron and my 18-50 Sigma to whatever he will throw at it! EEEK!!!:eek: :eek:


LOL. Well hey if he ever wants to try the 24-105mm f/4L up against his Tammy, he can feel free to buy me one and I'll run it. :D :eek:

[DonSchap]

a COLD RAIN on my parade, already.

Going into May, sunny days may be at a premium. It seems to rain every single Mother's Day & Memorial Day, here in Chicago, Illinois.

I'm pretty sure Britain suffers in the same way.

Thanks for the support, Cold... hmmm, the 11-18mm, eh? :rolleyes:

[aparmley]

I'd like to go "head-to-head"

"I'm your huckleberry, thats just my game."

"Say when."

just tell me what you want me to take a photo of Don. See the sigy - I got the 28-105 as well. . . so does Pete, and Jamie.

[DonSchap]

for my Tamron SP AF28-105mm F/2.8 LD to show up. I thought it would have been here by now. I hope tomorrow... or the fur will fly.

In the mean time... I've had to shoot stuff with this Tamron SP AF 28-75mm F/2.8 XR Di LD Aspherical (IF) Marco. (say that three times, fast). Darn thing is light as heck, though. A little limited in the long glass, but still... as I have found out, today... a very decent walk-around lens and it works with my EOS-3 35mm.

For "knock-around", outdoor shooting, I am still sticking with the Tamy 18-200mm Di II as my 'default' digital lens. It covers the bases and doesn't weigh enough to load me down... and it allows me to keep the 28-75mm Di on the EOS-3.

I'll let you know when I get my lens... but I was hoping Karin would take up the challenge... and force some results... that we all can experience. I figure since she and I haven't even touched our respective lens yet... whereas you guys have had plenty of preparation... it would be a little more... let's say, fair?

But, what the hey? Let's make a party of it. :D

When we all get our glass... let the games begin! :D

[DonSchap]

The Tamron SP AF28~105mm f/2.8 LD Asherical (IF) has arrived! -trumpets blow - cows genuflect - children cheer -

Yes, finally... after a seemingly very long and anxious week, my $330.00 prize has arrived. Man, this puppy has some weight to it... and an excellent padded lens case... with a leather Tamron logo sewn on it. (Yes, I'll get a photo of it later. I know you are all anxious to see the flippin' case, nevermind the lens... LOL :D )

Looking ahead, the last Tamron I am actually considering is the SP AF200~500mm f/5-6.3 Di LD (AF). I figure it may be a good break off point from all the other lenses I have. I am wholly dissatisfied with the Vivitar 500mm f/8 MF. It was fun to play and learn with... but not a serious lens, by any means.

Of course, there is still the matter of the the SP AF17-50mm f/2.8 Di II, due out next month. :rolleyes:

[ReF]

let us know if you find any optical/performance difference between the 28-75/28-105 besides the range

[aparmley]

By the way Don - I've only taken but maybe 250 images with my 28-105. So I'm sure a newbie could out do that in a weekend with their new lens. . .

[DonSchap]

I thought I'd do some shooting of an eye chart, under various conditions. I mean, hey, if they make you look at them... for eyeball optics... then they are probably a good enough choice for an ad hoc test.

I will also get some standardized color stuff, if I can... to color match against.

I will pick these up on Monday... set up and do the shoot. I would like to set up enough lighting to have the camera just about trigger the auto-flash pop up and then take the shot at f/2.8 on both lenses, at matching focal lengths... then a 90mm and a 105mm shot on the heavyweight.

The darn thing has a 82mm yawn on it. Lots o' glass.

One thing I did notice (and this is on the filter not the lens) is that the Sonia Circ. Polarizer doesn't seem to have enough threads to adequately hold the lens cap in place... it just keeps falling off with the slightest provocation. I know they narrow the width on these CPs to minimize the vignetting effect, but this has made it almost useless and a liability. I'm going to restack the CP, lens first, then the 'safety' filter on the front of it to extend these filter threads... and see if that'll probably do the trick. Makes it kind of pointless for the 'saftey', but we must be flexible, mustn't we?

To be honest, I am hoping the 105mm "pops" the shot... because the price delta between the two is substantial. There has to be something a bit more to qualify them other than the 75mm-105mm focal delta.

We shall see... :D

[DonSchap]

I found a web-site dedicated to lens testing... with standardized test patterns and charts galore.

http://www.normankoren.com/Tutorials/MTF5.html#using

This definitely is the bottom line is having a standardized source for the webpages. Take a look. Lots of great reading for understanding in here, too. :D

[DonSchap]

I ran my Tamrons through the specified tests and found out some significant facts...

The SP AF28-105mm f/2.8 LD Aspherical (IF) (model 176) does not play well with the digital camera line. Designed back when film-shooting was still king, there are some new circuit changes that will be needed to improve its response to both focus and aperture when used in conjunction with the digital body. It's off to the factory to have this done.

The new SP AF28-75mm f/2.8 XR Di LD Aspherical (IF) Macro (model A09), although the IQ was satisfactory, is coming up "soft". After seeing my target shots that I had used to gauge the response of the model 176 and the A09, the repair facility requested I ALSO submit the model A09 also for a warranty factory realignment.

Obviously... this does not bode well for my current shooting cycles, as I am being deprived two seriously powerful lenses for about two weeks. On the other hand, what I additionally found out was that the Tamron AF18-200mm f/3.5-6.5 XR Di II LD Aspherical (IF) (model 014) did not turn out too bad, all things considered in the tests. I did not have high expectations because of its wide focal range, but upon analysis, it shot better than both f/2.8s... at this time.

I shot all tests (on a tripod) with the all lenses set to 50mm and at a distance of 9 feet (55x50mm). I then shot each lens in the following way:

Manually defocusing on the high end
autofocusing back,
taking a shot,
and then manually defocusing on the low end,
autofocusing back,
taking the shot.

I got the results and really was shockingly disappointed with the model 176's results. Upon initial inspection, I suspect something must've gone wrong with the shot... (I accidentally bumped the tripod... the AF switch was in MF... something!) I mean, it was that far off! According to the repair center staff, after their own evaluation, the lens is fine (for use on a 35mm film body)... just not designed with the current circuitry to work with a digital body. Apparently it has some to do with its focusing response. There is a difference that the tech was not quite able to explain.

Shooting the Canon EF 50mm f/1.8 II, which, of course, turned in the sharpest results... set the benchmark for the others.

I'm not expecting miraculous results from a zoom. I never have... but what I witnessed today was... in its own way, educational.

If you are new at photography, I suggest you try the "target test", yourself... it was certainly worth the effort and not all that hard to do. :D It'll give you a better understanding of just what you are getting from your current "guns".

[aparmley]

sorry to hear it Don - hopefully upon return they'll be performing as desired.

[DonSchap]

Thanks, Andy...

It surely was a surprise... :eek:

But, at the same time... I found some vindication in knowing my good ol' AF18~200mm F/3.5-6.5 was the excellent buy I had suspected it had been all along. :)

I tell you, there is nothing like a decent prime, though.. to clear up the questions. For the $60.00 I paid for the f/1.8, it delivers. :D Money well spent as what really spead things up was being able to clearly demonstrate the sharpness issue with the documented pictures using the target.

I happened to see one of those EF 70-300mm f/4-5.6 IS USMs... the one Karin had identified with the "verticle issue". The salesperson presenting it knew nothing about the issue. How prevalent is this problem?