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06-18-2016, 01:01 PM   #1
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Comparing six lenses at 70mm

Just received a DA 70 Limited from a member here, and while I can already tell this will be my main lens for shooting people, I've noticed it is a focal length I often use with my DA 18-135 and DA 55-300. So the question that came to my mind is if the DA 70 has enough of an IQ advantage at f5.6 to justify changing the lens for pictures where no one will be intimidated by the extension of my lens and I don't want shallow depth of field. Here is the scene as shot.



All these pictures were cropped to about one quarter of the original pixels, I've used the built-in correction profiles in Lightroom where I could and I adjusted exposure by up to 3/4 of a stop to try to make everything equal. As much as I enjoyed Norm's double blind taste tests, I haven't hid EXIF information, so I might as well tell you which lens took which picture. They are in order of time when the picture was taken (just follow the ladybug).



DA 18-135. This is with exposure increased by 3/4 of a stop.



HD DA 55-300 WR. Increased exposure by half a stop. All six photos were exported with the same settings (1024 pixels on the longest side, low sharpening for screen), so any difference in image dimensions is because of my erratic cropping.



Takumar A 28-80 f3.5-4.5 zoom I used as my walk-around lens with my film cameras. Exposure reduced by 1/3 stop, tried focusing with highlighted edges in Live View as well as focus confirmation in the viewfinder, didn't seem to work any better either way, but at f5.6, I shouldn't have to nail focus.



Another MF lens, Pentax SMC A 70-210 f4. No adjustments to exposure, focused with the red square in the viewfinder.



SMC DA 70 Limited. Exposure reduced by half a stop. I am colour blind in one blue-green hue (it looks grey to me), but based on the weathered plastic flower pot and the tea candle holders, this picture has the truest colours. I didn't adjust colour temperature ("as shot" in Lightroom and AWB on my camera) and the adjustments to tint made by Lightroom are very subtle (setting automatically changed within the range of 12 to 16 based on recorded colour temperature).



Tamron SP AF90 Di Macro. It's not a 70mm lens, but I wanted something equally sharp to compare my DA 70 to and I've noticed differences in colour rendering with it as well. Exposure was decreased by 1/3 of a stop.

06-18-2016, 02:15 PM   #2
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Your DA70 looks off. Much softer than the 18-135 or 55-300.
06-18-2016, 02:35 PM   #3
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On my large 27" imac screen, the Tamron 90 Macro looks best by far of any of the others. Maybe you should sell those other mediocre lenses
06-18-2016, 03:06 PM   #4
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Accurate focus and tripod with 2sec delay are essential for comparison. The Tamron seems better focused than the DA70. (I have the DA 70, and it is a very sharp lens.)

06-18-2016, 03:23 PM   #5
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I agree with the others, I have the DA70 and its a superb lens. My copy beats my 55-300 and 18-135 hands down at f5.6 (its basically just as sharp at f4 too).

Check your focus - maybe try focusing in LV. Are you using the hood?
06-18-2016, 03:59 PM   #6
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I have a 70mm limited HD and it is really a superb lens regarding sharpnes and colors. Also the 40mm limited performs much better
as my Sigma 17-50 2:8
06-18-2016, 04:23 PM   #7
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QuoteOriginally posted by arnold Quote
tripod with 2sec delay
That's how I set it up and the focus point is always the turtle's chin. There are lots of round objects at different distances, if the lens is front or back focused, something other than the chin should be in focus. I took another look at pictures I took yesterday with the DA 70, from f2.4 to f5.6 and they seem to be sharper than these.
QuoteOriginally posted by kiwi_jono Quote
Are you using the hood?
Thank you, I think you have hit on my problem. The lens arrived yesterday without the screw in hood. After finding the hood on the DA 15 to be more of a nuisance than an aid, I didn't think it would affect the DA 70, but I took these photos with the sun high in the sky in the direction I had the camera aimed. I put hoods on the DA zooms and the Tamron and sure enough they have better contrast. The photos I took yesterday with the DA 70 were with the sun lower in the sky behind me (or indoors) and looking at them now they have also better contrast. Viewed close up, there is lots of detail, but the DA 70 picture I posted just doesn't have the same punch as some of the others.

---------- Post added 06-18-16 at 05:39 PM ----------

QuoteOriginally posted by Driline Quote
Maybe you should sell those other mediocre lenses
I like the Tamron a lot, but there is only so much you can do with a 90mm prime.
06-18-2016, 06:20 PM   #8
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QuoteOriginally posted by RGlasel Quote
I took another look at pictures I took yesterday with the DA 70, from f2.4 to f5.6 and they seem to be sharper than these.
Originally posted by kiwi_jono
There is an in depth report on the DA70LTD vs FA77LTD on this site, and it shows the DA70 well.
https://www.pentaxforums.com/reviews/da-70mm-vs-fa-77mm-limited-comparison/introduction.html


Last edited by arnold; 06-18-2016 at 06:26 PM.
06-18-2016, 06:40 PM   #9
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Very cool. One of the take aways from my own tests have been, for a given image, the "best lens" doesn't always produce the "best" image. The best lens may give you slightly better odds, take 5 pictures and choose the best one for each of 5 lenses and there will be surprises every time. The Tamron 90 DA 70 comparison doesn't surprise me at all. I know it will be blasphemy to DA 70 owners, but that Tamron 90 has done well in every test I used it for. The 18-135 has also produced some prime like results but not as consistently. When you are shooting real word, not test charts, many other factors come into play.

In every test I've done, some people actually prefer the rendering of the cheapest lens, to the most expensive, and theoretically the sharpest.

In this test I like the DA 18-135 followed by the Tamron 90. But I also know from my own tests, there's rarely a majority opinion. Usually the winner in terms of preference gets less than 50% of the vote. Usually less than 40%.

You have to ask, can you really claim a lens is a visibly superior lens, if only 35% of participants prefer it's image.

It's only really important if the owner of the lens prefers it, but I don't see any evidence that because person A thinks a lens is the cat's meow that person B will. The whole concept of selecting lenses from test charts and reviews seriously needs revisiting.

Last edited by normhead; 06-18-2016 at 06:50 PM.
06-18-2016, 08:13 PM   #10
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QuoteOriginally posted by normhead Quote
The whole concept of selecting lenses from test charts and reviews seriously needs revisiting.
It's hazardous to one's mental health. I've read the in-depth review of DA 70 vs. FA 77 at least three times and checked every posted photo I could find. I looked at the photos I posted here on three different monitors (technically two monitors and my laptop with an IPS screen) at different magnifications and how and where it was being viewed seemed to be the deciding factor. I think the colours from the Tamron are off, but when I flip back between it and the other photos I'm not sure anymore.

Like the DA 15, I get the impression that I will need some practice with the DA 70 (and that little screw in hood) to get the results I'm hoping to get. I do know that 70mm is a very useful focal length for me (especially for people shots) and there are situations where f2.4 and the DA 70's smooth bokeh are going to be better than the DA 18-135 at f4.5 or f5.6 (depending on which side of 70mm it sits at). For other situations, I'm not so sure it's worth the inconvenience of changing lenses.
06-18-2016, 09:12 PM   #11
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QuoteOriginally posted by normhead Quote
The whole concept of selecting lenses from test charts and reviews seriously needs revisiting.
QuoteOriginally posted by RGlasel Quote
It's hazardous to one's mental health
*AHEM* Reviewing lenses is hazardous to one's mental health. It is easy to criticize lens tests for not being comprehensive enough and not encompassing every use scenario - but reviewing lenses isn't easy. There are variables within the variables and if they are not controlled: a katamari* of mistakes will eliminate any credibility you have as a reviewer.


*jp: mass, cluster. I like this word, and have been trying to get it into the public Lexicon.
06-18-2016, 10:48 PM   #12
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Your DA 55-300 looks fine at this aperture compared to your HD 70mm, so I wouldn't switch out unless you needed the aperture wider.

You can also see that on the highlight on the board, behind the turtles head that the HD 70mm is exhibiting more green discoloring. Which is a little surprising.

QuoteOriginally posted by Driline Quote
On my large 27" imac screen, the Tamron 90 Macro looks best by far of any of the others. Maybe you should sell those other mediocre lenses

Keep in mind that that's at 90 rather than 70mm. So if the photo was taken from a tripod from the same spot, (which it was because otherwise the perspective would have changed) the 90mm would be zoomed in closer, and would've therefore been cropped less severely in this test, this of course giving the 90mm an unfair advantage.
06-19-2016, 03:26 AM   #13
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QuoteOriginally posted by RGlasel Quote
It's hazardous to one's mental health. I've read the in-depth review of DA 70 vs. FA 77 at least three times and checked every posted photo I could find. I looked at the photos I posted here on three different monitors (technically two monitors and my laptop with an IPS screen) at different magnifications and how and where it was being viewed seemed to be the deciding factor. I think the colours from the Tamron are off, but when I flip back between it and the other photos I'm not sure anymore.

Like the DA 15, I get the impression that I will need some practice with the DA 70 (and that little screw in hood) to get the results I'm hoping to get. I do know that 70mm is a very useful focal length for me (especially for people shots) and there are situations where f2.4 and the DA 70's smooth bokeh are going to be better than the DA 18-135 at f4.5 or f5.6 (depending on which side of 70mm it sits at). For other situations, I'm not so sure it's worth the inconvenience of changing lenses.
Shame to hear that the DA 70 is taking some work for you to get a handle of. I don't have the DA 70, but I do have the FA 77, and there is something about that lens - every photon it captures turns to gold. The only time I'll outright reject a photo with it is when the focus is off (and that is my fault, not the lens'). Makes it very hard when I have several shots of the same subject/scene as I need to pick a winner. ugh.

No other lens in my collection has this magic ability. Plenty have pixie dust, but none work like this all the time. I have its little brother (FA 43) and it needs to be worked to bring out its best (though it is just as good when you hit that point!). For me there is just something about my FA 77 - the focal length, the rendering, the oodles of gorgeous contrast, it is damn hypnotic! One day I'll ensnare a FA 31 to see if lightning strikes twice, but I think it may be that every photographer has the one lens which just matches them perfectly and I think I have already found mine - I guess I should be happy, there are probably plenty of people who never find that lens, though given I am more of a landscape guy (and generally am crap at portraits) I have to wonder about the irony here...

I hope you can get to the point with your DA 70 that every time you attach it to your camera you know you are on a winner. It is a great focal length and the Limited pixie dust helps make Pentax special.
06-19-2016, 04:59 AM - 1 Like   #14
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When it comes right down to it, there are very few primes so good it's worth taking a zoom off for.

All lenses these days are pretty good. At web size the differences are hardly even visible If most of your out put is 1280x 800, you are 5x oversampling with a k-3.

My output for the last month is about 500 files. IN the last year I've printed 280 image, most of them no larger than 3x5, some of them as large as 11x14 and a couple of canvases and metallic prints. If you look at the resolution standard, lw/ph and assume that a print resolution of 100 lw/ph is going to look sharp, 34 images have used 3/4s of the resolution available to me, another 10 have used half, The huge majority have used less than 15% of the resolution available.

IN this context, going on about how good your lenses are is pretty much insane. If you assume I'm running at about 600 keepers a year, out of probably 15,000 to 20,000 shutter actuations, 5% of the keepers are going to be printed, and I published a book this year, so that is unusual. Most years it's more like 10-20 printed images, That would be .016 percent or something like that. Way less if you look at shutter actuations not keepers.

So my point would be I carry my primes for those rare occasions when it might be worth my while to switch. But most of the time it isn't. And I've never had an instance where I though "I wish I'd taken this with a prime." There are many instances where I did switch, and really all switching did was cost me images in terms of time spent changing lenses.

The only real purpose for primes as far as I can tell would be generally faster apertures, and I think some people are affected by information over load when they have lot of options and it makes shooting unpleasant for them. If you're the type of person who can't cut through the chaff to get to the wheat, a zoom lens is an intimidating proposition. The number of combinations FL and aperture goes off the charts when you switch to a zoom. With a prime you have one focal length and maybe 6 or 7 ƒ-stops. Reality is contained in a very small box. Some folks don't have a problem with the infinite number of choices presented by a zoom lens.

For most of what I do, lens choices are based on FL and Aperture. Need variable FL? get a zoom, need a wider aperture, get a prime.
While the jury is still out on the 77, most of my lens selections are based on factors other than pixie dust or resolution.

IN the real world of 1000-3000 image a month, no lens has stood out for me so much, I would put it on the camera, because it was a prime not a zoom, or for even 300 lw/ph of test chart resolution. IN fact the opposite is true. I find, the biggest factor in how many wow images I get with a lens, is how much I use it. If you come upon great light you grab your favourite lens and start shooting. It's a self fulfilling prediction. When I switch things up during a session and use multiple lenses, most of the time, I can't tell which lens I used for which image without looking at the exif.

Even a DA 18-55 gives you a great image in good light if focal length and aperture are appropriate.

Most of the lens banter on the site IMHO is a lot of talk about the least important part of photography. Lens selection.
06-19-2016, 06:24 AM   #15
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Your DA70 is broken. Send it back

https://www.flickr.com/search/?user_id=20564446%40N00&sort=interestingness-d...a70&view_all=1
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