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05-02-2014, 11:00 AM   #31
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QuoteOriginally posted by Driline Quote
I liked picture 5 the best. The cheap little DA 35 2.4 of which I own as well. Sweet....
I only had a few shots taken with that lens, based on the number of shots I had to select from, it's done fantastic. Not only that, that image was taken at a spot I've been to over and over through the years with various lenses, and it' one of my favourite images ever taken there based on image quality. The one I do like better were based on better light.. not better lens performance.

QuoteOriginally posted by tuco Quote
This plastic lens in a Holga looks way better scaled down than full size in terms of sharpness.



That's why I said ""as a general rule, an image that looks better full size also looks better small". Maybe 90% of the time, 10% of the time, an image you think is a write off will look good reduced to 1080 if it has other things going for it.

QuoteOriginally posted by ChristianRock Quote
My favorite was #2, which I thought was the DA 35 2.4. But it's the DA 21 - which I'm trying to talk myself out of, but it gets harder and harder to do that!

That was a thread that I enjoyed a lot, Norm. Thank you
Your welcome... the 21 is a gem for sure...

05-02-2014, 12:08 PM   #32
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First I made my choice
Zoom 1378
Prime 2456
Then I did an average of the previous 10 replies and got Zoom 1468 Prime 2356 so I looked at the pix again.
It seemed to me that the average Zoom choices had less contrast or snap and the average Prime choices had more contrast.
Are we influenced more by contrast than other factors? Just playing around. The highest number of votes for Prime was #2 and
the highest number of votes for Zooms was #4.
05-02-2014, 01:48 PM   #33
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QuoteOriginally posted by OldGeaser Quote
Are we influenced more by contrast than other factors? Just playing around.

I have often wondered what factors are most important in determining IQ for a still image. It seems like someone should have established that by now. I recall a few years ago when I purchased my first HDTV I read that someone actually determined that the factors influencing HDTV image quality were, in succession:
a. Contrast ratio
b. Color saturation
c. Color accuracy
d. Resolution

At that time, everything in the news was all about resolution. Odd though that it was fourth on the list for HDTV IQ. Seems that we would have some kind of a list like that for still images.
05-02-2014, 02:00 PM   #34
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QuoteOriginally posted by GlennG Quote
I have often wondered what factors are most important in determining IQ for a still image. It seems like someone should have established that by now. I recall a few years ago when I purchased my first HDTV I read that someone actually determined that the factors influencing HDTV image quality were, in succession:
a. Contrast ratio
b. Color saturation
c. Color accuracy
d. Resolution

At that time, everything in the news was all about resolution. Odd though that it was fourth on the list for HDTV IQ. Seems that we would have some kind of a list like that for still images.
I doubt it would be much different.

05-02-2014, 03:13 PM   #35
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Thanks for this thread, Norm. Scientific? Of course not. But a nice illustration of how most of our obsession over lenses is a waste of time and money.

Apart from the fun of obsessing over lenses, of course

And, yes, there are plenty of situations where you need faster or sharper or whatever. But still, for me, my 18-135 would most of the time do the job just fine.

Not that I would ever give up my limiteds. Or fast fifties.
05-02-2014, 04:26 PM   #36
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When lenses are really close in terms of sharpness, how a lens renders it's out of focus can decide which is better. There are no bokeh examples here.
05-02-2014, 05:16 PM   #37
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QuoteOriginally posted by tuco Quote
When lenses are really close in terms of sharpness, how a lens renders it's out of focus can decide which is better. There are no bokeh examples here.
True, and some of the same lens elements that contribute to bokeh also contribute to diffraction and specular highlight effects, not to mention microcontrast. It would be interesting to see some reality-checks done in those areas, as well.

Bokeh, I must say as an aside, seems to me to be in deep danger of becoming a photographic cliche. It is, obviously, useful for subject isolation and abstract effects, but how much bokeh and of what quality is an interesting question. I struggle to optimise the use of the thin DoF available on my A50/1.2, much of the time, and I haven't yet used it on my film Pentaxes. Andreas Feininger's book on colour, written in the film era but still relevant today, ranged over the variety of lens effects available for subject isolation. Bokeh (even ough the term wasn't used then, except perhaps in its native Japan), was just one.

We may be disappointed or just surprised by the results of such tests, but, being properly scientific about the process, isolating different characteristics, such as Norm has done here, contributes positively to our collective understanding of the outcomes of the photographic picture-making process. More power to you, comrade.
05-02-2014, 06:19 PM   #38
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QuoteOriginally posted by tuco Quote
When lenses are really close in terms of sharpness, how a lens renders it's out of focus can decide which is better. There are no bokeh examples here.
Next time I get a chance, I'll put together the same lenses , or maybe a few different ones... so we can do the bokeh test....unless of course someone else wants to give it a try.

05-02-2014, 07:33 PM   #39
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The 60-250 is very impressive with that #3 shot. Threads like this can become LBA fuel. I know it has a good reputation but I would have never guessed the longest zoom on the list for that shot.
05-02-2014, 07:53 PM   #40
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QuoteOriginally posted by RobA_Oz Quote
Bokeh, I must say as an aside, seems to me to be in deep danger of becoming a photographic cliche.
I have to agree 100% here.

Back in the day, I used a 135 film SLR for my casual shots, and like most casual shooters, rarely printed over 3x5 or 4x6 inches.

These days, everything fills a 23-inch monitor, and the out-of-focus areas are much more obvious. F/2.8 on APS-C is wide enough for me most of the time, thanks.

I think a lot of hipsters are obsessed with ultra-shallow DOF because it is new to them, and shows everybody that they are not shooting on a cell phone.

It has its place, but can become quite distracting when overused. And I find that most shots that are helped by it, could have been improved just as much, by better composition.
05-02-2014, 08:38 PM   #41
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QuoteOriginally posted by Tanzer Quote
...
I think a lot of hipsters are obsessed with ultra-shallow DOF because it is new to them, and shows everybody that they are not shooting on a cell phone.
I gotta say you are thinking wrong. Selective focus has be around since, well, forever. And it is a very effective photographic tool. I don't mean to pick on member osv's picture here but it demonstrates that some lenses can't handle complex structure in their out of focus rendering very well IMHO. And it can totally be a distraction. Check out the cactus flower background.

https://www.pentaxforums.com/forums/76-non-pentax-cameras-canon-nikon-etc/110...ml#post2782319
05-03-2014, 09:32 AM   #42
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QuoteOriginally posted by tuco Quote
I gotta say you are thinking wrong. Selective focus has be around since, well, forever. And it is a very effective photographic tool. I don't mean to pick on member osv's picture here but it demonstrates that some lenses can't handle complex structure in their out of focus rendering very well IMHO. And it can totally be a distraction. Check out the cactus flower background.

https://www.pentaxforums.com/forums/76-non-pentax-cameras-canon-nikon-etc/110...ml#post2782319
I agree that bokeh is a very real lens attribute. What I'm saying is that in pratice, bokeh is too often overused, just because the shooter can.

I have a Sigma 28-300 "Hyperzoom" that has horrific bokeh, which is why I never take that lens unless I have to. On the other hand, I don't always have to take out the FA31 or DA*55 over my slower DA Ltds, and even when I do, I don't do so with the sole intent of obliterating the background by shooting everything wide open.

Norm had an earlier test of a Sigma vs. Pentax lens, some wolves in the trees, and the bokeh was the clear giveaway to most participants. Looking forward to the next challenge.
05-04-2014, 06:45 AM   #43
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Being as the thread is fading a bit I thought I'd throw this in just for the fun ot it:

One taken with a 50mm Zeiss ZK at about 5 feet? and the other with a 350 buck Sigma 18-250mm macro super zoom taken at 250mm at about 25 feet.
Both are full frame.

My own opinion is that there is not enough real world practical difference between the two to lose any sleep over.

Last edited by wildman; 05-17-2014 at 05:21 AM.
05-04-2014, 07:13 AM   #44
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QuoteOriginally posted by wildman Quote
Being as the thread is fading a bit I thought I'd throw this in just for the fun ot it:

One taken with a 50mm Zeiss ZK at about 5 feet? and the other with a 350 buck Sigma 18-250mm macro super zoom taken at 250mm at about 25 feet.
Both are full frame.

My own opinion is that there is not enough real world practical difference between the two to lose any sleep over.
That for me is the issue. When I'm walking around with my 18-135, will I take the time to take my 18-135 off to put on another lens. If I have time, I will put on the 21 or 35... or 60-250, ...but much of the time, taking advantage of ephemeral light is more important than changing from zoom to prime.
05-04-2014, 07:48 AM   #45
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QuoteOriginally posted by wildman Quote
Being as the thread is fading a bit I thought I'd throw this in just for the fun ot it:

One taken with a 50mm Zeiss ZK at about 5 feet? and the other with a 350 buck Sigma 18-250mm macro super zoom taken at 250mm at about 25 feet.
Both are full frame.

My own opinion is that there is not enough real world practical difference between the two to lose any sleep over.
Is the first photo the Zeiss?
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