Tamron 28mm f/2.5 lens [REVIEW]

Orio · Expire: 2012-12-04

I want to try a lens review in the format that I will use on my website (when I will find the time to make it).
Please let me know what you think of the format, and if there is something you would like to be added.
I will not make scientifical tests or even bookshelf tests. I am not up to the task and I'm not that much interested either. My reviews will be very practical, oriented to the actual use of the lens rather than to make scientifical measurements.

TAMRON 28mm f/2.5

Look and build
The lens is small and compact. The barrel is of anodized aluminium and seems pretty solid and safe. The aperture ring however is plastic and feels very cheap and easy to damage. This is bad news because the aperture ring is a critical part in the build and working of a lens. Frontally, the lens is surrounded by a large quasi-flat black area made of tiny concentrical rings. I think that the design here was to make the surface rough in order to capture the light and prevent nasty reflections that a smooth surface could cast onto the glass. This however has a drawback, in that it also gathers dust and dirt.

Features
The lens widest aperture is f/2.5, which is respectably fast especially for a budget lens. As we will see, however, the full aperture is not really useable because of optical problems.
A very good news is that the narrowest aperture is f/32, which is quite uncommon and very useful in a wide angle lens, as it allows (if properly focused) to have a virtually limitless depth of field, which can be used for great effects in landscape pictures.
The minimum focusing distance is around 24 cm., which means to get close enough to a subject to make it become a prominent feature. This is also a good and useable feature, although probably not enough to call this lens a "macro" (which in fact is not called).
The focusing ring works with a pleasant smooth resistance and precision.
The aperture ring works in half stops and feels harsh and abrupt.
Like all Adaptall lenses, this lens too is not directly mountable on a camera, but requires the application of an adaptor ring. Adaptall rings were produced for most camera mounts of the time, and someitmes are still available in shops (and always available used on auction sites).
The lens does not have an "Auto-Manual" switch, and it's set at Auto at all times, so if you intend to use it with an M42 Adaptall ring and with a camera that does not support the M42 Auto feature, you will have to find a way to mechanically keep the aperture pin pressed in order to be able to stopping down the aperture blades.

Performance
Wide open the lens is close to unuseable. There is important vignetting, and at the edges of the frame the images show significant flare and chromatic aberration. The in focus portion shows however an excellent sharpness already wide open.
Stopped down to f/5.6 the lens becomes nearly perfect. The vignetting is gone or almost, gone are also the flare and CA, and the sharpness reaches it's peak. This lens can be nearly as sharp as a Leica lens, for a fraction of the price.
The closeup performance is very good, the objects are rendered with good microcontrast and enhanced texture detail.
Like most wide angle lenses, the bokeh is not the strong point of this lens. Wide open shows double lines and quite ugly donut effect in the highlights, with a pronounced outer ring. The bokeh becomes more pleasant stopping down, and at f/5.6 it's not disturbing anymore except for the highlights.
Geometrically-wise, the lens shows noticeable barrel distortion. While not tragic, and surely not worse (and in most cases better) than the distortion of comparable price 28 mm lenses, it is however noticeable enough to not make of this lens the ideal tool for architectural photographs. For the occasional building picture, however, it is acceptable.
Colour-wise, I am very pleased by this lens. Differently from most Japanese lenses (Nikon, Canon, Pentax), this lens does not show a warm cast, but proves to be quite neutral in the colour rendering. I tested it by shooting at a fixed 5500 K value, in order to avoid the camera to influence the result. Also saturation wise this lens proves to be better than most Japanese lenses, and although not as saturated as the German and Russian lenses, it renders purer colours than a typical Nikkor or Canon lens.
Very importantly for a wide angle, this 28mm lens shows great resistance to flare, except wide open. It is actually one of the strong points of this lens: even when shooting against the sun, the flare is very well controlled, and the picture maintains an enviable contrast. On the other hand, ghosting is on the poor side: ghosts of the aperture blades tend to appear very soon as you direct the lens towards the sun, although not at all angles. So if you frame carefully you may be able to avoid them even without a lens hood (which is still highly recommended). If you are taking an important picture against the sun, you should always remember to test the frame at f/32, this will show you the presence of ghosts that may be not immediately visible at wider apertures (but would show up printed).

Conclusions
This lens delivers more than it's budget price, and it's surely a very wise buy and an excellent price/performance ratio bargain, especially if you already own an Adaptall-2 ring. The deal becomes less attracting if you also have to buy an Adaptall-2 ring for it. They usually are not cheap even when used, and sometimes also hard to find for certain mounts (such as M42 for instance). If it was the lens alone, I would say that it would beat all competition in the price/performance contest; with the purchase of the necessary adaptall ring, other budget 28mm lenses, such as the excellent Nikkor Series E 28mm f/2.8, can become competition for this lens.
Strong points:the ability to stop down to f/32, the excellent flare control, the excellent sharpness at all apertures, the well balanced colour rendition, the compact size and portability.
Weak points:the poor wide open performance in the corners and edges, the problematic ghosting when shooting against the sun, and the cheap build of the aperture ring
Overall, the Tamron 28mm f/2.5 is a very good buy. It's not a perfect lens, but if used wisely and accepting the inherent limitations of wide open performance, it can deliver results that are comparable with those of much more expensive lenses.

Evaluation table (1 to 5 stars and + for excellence. Legenda: 1=poor 2=mediocre 3=average 4=good 5=very good 5+=excellent)

Build = * * *
Aperture range = * * * * *
Minimum focusing distance = * * * *
Focusing ring performance = * * * *
Aperture ring and controls performance = *
Sharpness (=resolvance + microcontrast), wide open = * * * *
Sharpness (=resolvance + microcontrast), stopped down = * * * * * +
Macrocontrast = * * * * *
Corner/edge performance, wide open = *
Corner/edge performance, stopped down = * * * * *
Close-up performance = * * * *
Distortion type = barrel
Distortion amount = * *
Colour balance = * * * * *
Colour saturation = * * *
Flare control, against the sun = * * * * *
Ghosting, against the sun = * *
Highlight Bokeh, wide open = *
Highlight Bokeh, stopped down = * *
Flat Bokeh, wide open = * *
Flat Bokeh, stopped down = * * *
Price/performance ratio, lens only = * * * * *
Price/performance ratio, with Adaptall ring = * * * *

Image samples will follow, later
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Attila · Expire: 2025-11-18

Very detailed review ! Good one!

Orio · Expire: 2012-12-04

now some sample images, each with specific comment.

Very good performance close-up, even wide open, but the bokeh shows doubling of lines and bad donut effect in the highlights.

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Orio · Expire: 2012-12-04

At f/5.6, the bokeh loses the doubled lines and becomes much more pleasant.

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Orio · Expire: 2012-12-04

Bokeh and closeup performance again.
At wide open, the bokeh shows again its ugly face with the doubled lines and the bad donuts.
The closeup performance of the lens is confirmed very good.

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Orio · Expire: 2012-12-04

At f/11, the bokeh becomes pleasant again, and surprisingly smooth.
The closeup detail is rich with microcontrast and detail.

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Attila · Expire: 2025-11-18

Man you will change my mind to keep my copy Smile

LucisPictor · Expire: 2013-12-03

Wow! This is very detailed, Orio! Shocked

If you are going to describe each lens like this, your website will perhaps be the most informative source on the lenses you have.

Excellent overview and very precise information even for people who know a lot about lenses.

Actually, I am very much looking forward to enjoying your site! Very Happy

For each lens we both have, I will link on my site to your site!

Carsten

Orio · Expire: 2012-12-04

Thank you. Yes this is my planned format, all my reviews will be like this.
I'll be glad to exchange links! but who knows when my site will be ready? Confused

Orio · Expire: 2012-12-04

Very good colour balance, good native saturation.

Orio · Expire: 2012-12-04

The barrel distortion is evident and will be a problem in architectural photographs.

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Attila · Expire: 2025-11-18

I am thinking on smart link exchange between forum member sites.For example you have an article for Tamron 28mm f2.5 for example. You don't link directly Carsten's or Orio's site directly. Instead link an url like this

mflenses.com/linkexchange.php?site=1&lens=tamron_28mm_f2_5&num=5

this link will get back 5 url from other members (Seymor,Orio,Carsten etc related links.

site = identify who requested /to avoid give back own link/
lens = this lens related article
num = how much link would you get back

result will be looks like this

Tamron 28mm f2.5 on orio.ws
Nice review at Carsten's site
....
Every member will able to fill this link db with links and link text what he would see on other sites.

What you think about guys ?

Orio · Expire: 2012-12-04

Orio · Expire: 2012-12-04

Large scene with f/11 depth of field

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Attila · Expire: 2025-11-18

LucisPictor · Expire: 2013-12-03

Attila, I do not know how those smart links work, but if they work, they are a nice idea! Wink

Orio · Expire: 2012-12-04

Wide open, the right corner shows the problem with corner image quality (evident flare, and some CA that is visible only at full size).

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Orio · Expire: 2012-12-04

Stopped down, the corner problems are gone.

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Orio · Expire: 2012-12-04

The sharpness is already good wide open (but you can also see the quality problem in the corners)

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Orio · Expire: 2012-12-04

At f/5.6, the sharpness becomes excellent!

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sqwall · Joined: 24 Apr 2007 Posts: 195 Location: Varna, Bulgaria

Great Review Orio. Very Very Comprehensive and detailed.

I agree with both hands up about the link exchange. My site is organized like this and I have a separete link about any lens and any body Smile

.

Attila · Expire: 2025-11-18

Hopefully I will have time sometimes to do link exchange application, I suppose this is important for both of us.

sqwall · Joined: 24 Apr 2007 Posts: 195 Location: Varna, Bulgaria

I dont know what application can be used. But I think that there might be a module or component for PHP CMS systems to provide registered users with access to this particular stuff.

Orio · Expire: 2012-12-04

sqwall · Joined: 24 Apr 2007 Posts: 195 Location: Varna, Bulgaria

I can help you Smile

. I have experience in preparing sites using Joomla CMS.