[audiobomber]

I tested the Tamron AF70-300mm F/4-5.6 Di LD Macro vs the Pentax smc P-DA 55-300mm F4-5.8 ED about a month ago. I decided to post the results here because some people are questioning the Pentax's sharpness. I believe the Tamron is (sorry, was) considered the sharpest budget telezoom at 300mm.

The test shots were taken mounted on a tripod, at full zoom, ISO 200, F/8, +0.3EV. The Tamron shutter speed was 1/640s, the Pentax 1/500s. I don't know if the light shifted or if the Pentax meters a little brighter than the Tamron. The slight yellow blur on the right side of the photos is a branch that was in front of my (open) window.

Tamron at 300mm:



Pentax at 300mm:



Tamron full sized crop:



Pentax, full sized crop:

[Jodokast96]

Yeah it's sharper, but hey look at that, no fringing!

[audiobomber]

Yeah it's sharper, but hey look at that, no fringing!

I wouldn't say "no" fringing. The Pentax shows less PF than the Tamron, that's for sure. But it's definitely not immune. I've taken a few shots that show PF and CA using the 55-300mm.

[k100d]

where was the focus point? the pine tree tip is much sharper on the Pentax than the Tamron

[Buddha Jones]

The Tamron really chapped my hide with all that PF, it ruined my favorite shot at the Atlanta Aquarium. Oh well I shall return with better kit and redeam myself!

[audiobomber]

where was the focus point? the pine tree tip is much sharper on the Pentax than the Tamron

I focussed on the second story window on the right hand side of the house (specifically the lower left corner of the window).

[TourDeForce]

where was the focus point? the pine tree tip is much sharper on the Pentax than the Tamron

Can't argue much with the results. The Pentax lens is definately the better glass. Based on this it will replace my Tamron in short order.

Still, for a budget lens at under $150, the Tamron serves well. Most big zooms will have some issues at the long end and the Tamron is no exception. Tamrons strongest showing is at about 220mm and below. Above that the sharpness tapers off. Pentax seems to have handled the longer focal length quite well.

My question before I plunk down more cabbage:

How does the Pentax lens do in the rest of the zoom range? Specifically between 70 to 100mm in comparison to the Tamron?

---

Last edited by TourDeForce; 07-10-2008 at 04:32 PM. Reason: added question

[KungPOW]

Thanks for posting the comparison. Info like this helps us all make choices for our kit.

Even though I just bought the Tamron 70-300 Di, and I can see here that the Pentax is better, I'm ok with that.

To me, its all about what the lens costs. Price/performence. The Pentax is about twice the cost of the Tamron (in the stores I use), and so it should have better characteristics.

But until I see how much I really use the Tamron, I'll be ok with the purple fringe. Eventually I'll know when it comes time to upgrade if the path should be the Pentax 55-300, or a Sigma APO 2.8 something or other.

Ok. I'm lying. The purple fringe drives me nuts. But it builds character.

[audiobomber]

My question before I plunk down more cabbage:
How does the Pentax lens do in the rest of the zoom range? Specifically between 70 to 100mm in comparison to the Tamron?

Here you go, you can pixel peep for yourself: Picasa Web Albums - Dan - Telephoto test

The Tamron is an amazing value, I agree. But as a user of both lenses, I find the pricier 55-300mm has richer colours, smoother bokeh, better contrast and less PF. It is noticeably sharper at 300mm, especially wide open. Unfortunately I forgot to take that shot on test day.

The Tamron focusses significantly closer. The Pentax has better IQ for flower heads and butterflies, but is unsuitable for insect-sized macros. The Pentax quick shift focus and wider angle make the Pentax a much nicer lens to shoot with for general photography. I missed a lot of bird shots with the Tamron while fumbling for the AF/MF switch. I like to take a variety of shots, and 55-300mm is a much more versatile range than 70-300mm.

Here's an example of the colour richness I see from the DA lens. This was shot wide open at 300mm, ISO 800, 1/320s.

[audiobomber]

the pine tree tip is much sharper on the Pentax than the Tamron

It was a windy day. I suspect a gust blew the tree, causing it to blur in the Tamron photo. If that's what happened, I'm kind of surprised, considering the shutter speed was 1/640s.

[Jodokast96]

No, it's the lens, not wind, unless it was blowing the tripod. Just look at the house, I doubt the wind was blowing that too, lol.

[Alfisti]

Interesting thread.

I don't mean to be an ass but try to use Manual mode so the exposure is the same. What is really odd here is that the tamron used a faster shutter speed (this lens is TERRIBLE for metering, I often dial in +1.3 Ev) but the image looks brighter.

Now this is a key issue, as on closer inspection "brighter" may simply be the lack of contrast and washed out glare.

In there images the Pentax just $hits all over the Tammy, this is the first exampel I have seen like this.

Another thing to note, the branch in the foreground appears much more in focus with the Tammy shot.

[audiobomber]

Interesting thread.

I don't mean to be an ass but try to use Manual mode so the exposure is the same. What is really odd here is that the tamron used a faster shutter speed (this lens is TERRIBLE for metering, I often dial in +1.3 Ev) but the image looks brighter.

Now this is a key issue, as on closer inspection "brighter" may simply be the lack of contrast and washed out glare.

In there images the Pentax just $hits all over the Tammy, this is the first exampel I have seen like this.

Another thing to note, the branch in the foreground appears much more in focus with the Tammy shot.

But isn't it incredible that even with the $130 Tamron I can count the bricks on a white house in the next subdivision? I manually focussed on the point of interest on the white house in the 300mm test. Then I set it to AF and took the shot. Focus was where it needed to be.

I don't think Manual exposure is a good idea for natural lighting. Lighting varies too much during the test. Besides, I figure that how the lens meters on Auto is an important criterion.

Note that I used +.3EV and focussed on a white house, which kind of plays into the Tamron's weaknesses (low contrast and softness at full range, PF for high contrast scenes).

I"m not about to repeat this test. I'm not much interested in the Tamron for long distance shooting. I will likely use what I learned with this experience to compare the 55-300mm and the DA 18-250mm I received today. I will certainly be hauling the Tamron out for macros when my new Raynox 250 arrives.

[simonkit]

This test definitely matches with my own experiences.. having owned the Tamron 70-300 DI LD & Sigma 70-300 APO previously....the Pentax betters them both & I'm particularly impressed by it for a consumer lens, of course it should be better as it costs much more than either the Sigma or Tamron, worth it though

simon