Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-26-2015, 02:54 AM   #121
Site Supporter




Join Date: Mar 2009
Location: Gladys, Virginia
Photos: Gallery
Posts: 16,243
QuoteOriginally posted by osv Quote
the biggest take-home for me with roger's testing was that he tested 10 copies of three different lenses, and the results were all over the map for two of the lenses, which speaks volumes about sony q.c.

second point was that roger stated in the comments that the sigma 35/1.4 variance was just as bad as the sony fe35/1.4 variance, which will matter to pentax people if sigma releases it in a ff k-mount.

i don't understand how dxo can rate lenses that have so much variance, and i definitely don't get the extreme differences in distortion measurement, for optical bench vs. imatest, he should have explained that... if he even could.

wrt to your point about the raw files getting distortion correction:
"Despite being a wide-angle lens, the FE 35mm ƒ/1.4 Zeiss lens displays impressive distortion control, on both full- and sub-frame cameras. Like vignetting, Sony cameras can apply in-camera corrections for distortion. We measured both with and without, and it does appear that Sony RAW files are affected with this correction as both tests showed nearly identical results. We found average barrel distortion was well under +0.5% and even the maximum value of distortion -- typically displayed in the corners -- was still under the +0.5% level." Sony Lens: Primes - Sony FE 35mm f/1.4 ZA Zeiss Distagon T* SEL35F14Z (Tested) - SLRgear.com!

are those corrections just numbers in the raw file, being applied by the raw processor, which is how everything else is done in a raw file? or is the image permanently altered.
We already know that Sigma's quality control isn't great. DXO Mark's copy of the Sigma 35 f1.4 for Nikon was stellar, the one for K mount was decent. But I don't trust DXO Mark's evaluation for exactly that reason -- that and it is harder to find the numbers behind the number (which tends to be mostly t score and resolution).

As beholder says, Roger Cicala tests multiple copies of each lens and seems to be pretty impartial, releasing his results without a lot of fanfare or advertisement. I would view the results he got as problematic for Sony, considering the price of the 35 f1.4, it should be really, really good before adding lens corrections.

10-26-2015, 03:36 AM   #122
Pentaxian




Join Date: Apr 2007
Location: Romania
Posts: 9,336
QuoteOriginally posted by Rondec Quote
We already know that Sigma's quality control isn't great. DXO Mark's copy of the Sigma 35 f1.4 for Nikon was stellar, the one for K mount was decent.
From what I see, DXOMark tested the Sigma 35mm f/1.4 on the D800 - obviously, it will resolve more bogo-pixels on the larger format.
10-26-2015, 03:54 AM   #123
Site Supporter




Join Date: Mar 2009
Location: Gladys, Virginia
Photos: Gallery
Posts: 16,243
You can choose what they tested it on. They tested it on the D7100 as well. Sigma 35mm F1.4 DG HSM A Nikon on Nikon D7100 vs Sigma 35mm F1.4 DG HSM A Pentax on Pentax K-3
10-26-2015, 04:19 AM   #124
Pentaxian




Join Date: Apr 2007
Location: Romania
Posts: 9,336
Thanks. Their search tool didn't show me the Nikon DX tests... probably a glitch.
The general scores appears identical, except for chromatic aberration. Also, the lens is "best@f/1.4" on the Nikon, and "best@f/2" on the Pentax.

Could be anything. Lens variability, test variability, testing methodology, camera.

10-26-2015, 07:23 AM   #125
osv
Pentaxian




Join Date: Mar 2007
Location: So Cal
Photos: Gallery
Posts: 2,080
QuoteOriginally posted by Nicolas06 Quote
Explain us then what an extension tube does or why you can't simply use any optics on any camera in particular when the registration distance of the actual lense is shorter than the registration distance of the target camera.
get back to us when you have some experience with mirrorless cameras and adapters.

QuoteOriginally posted by Nicolas06 Quote
Optics are high precision material that need perfect alignement, the smallest change in distance between 2 elements can have huge effect on picture quality.
you aren't reading what's already been posted.

---------- Post added 10-26-15 at 07:47 AM ----------

QuoteOriginally posted by beholder3 Quote
Imatest and single copy means nothing if you even want to apply enthusiast amateur standards to reviewing.
i have the imatest software, my thought was that it had value for just testing the glass that i owned... so i printed up a big chart at costco and put at least 200 images through it... i never got the lighting right, and my target was much too reflective; in the end i gave up using it for resolution testing, because i couldn't get consistency... break the camera setup down, put it back together with the same lens, get different resolution numbers... i tried everything i could think of, including physically measuring the side distances and using bubble balancers, to make sure that the sensor was parallel to the surface of the target.

that was with just one copy of a lens... when i tried doing resolution testing on three copies of the sigma superwide2, it was nothing like what i could easily see when i compared infinity photos of the same scene... i think that it can be accurate, if the methodology is consistent, but it'll only represent how the shot will look at close distances.

the distortion and vignetting measurements seemed consistent, but like you indicated it's only done at close distances.

however, when you see bad distortion numbers with imatest, you'll see the distortion problem in photos shot at distance... the problem with looking at distortion at distance is that if the camera is tilted up or down, it will make the distortion look much worse... and i'm not sure how you'd quantify it, even if you had the camera level.
10-26-2015, 11:38 AM   #126
Pentaxian
redrockcoulee's Avatar

Join Date: Nov 2009
Location: Medicine Hat
Posts: 2,135
QuoteQuote:
Wonder how Ilford's film and processing business is going?
They were doing good when they were sold, hope they continue to do so with the new owners, especially their annual ultra large format order.


As long as they continue to support cropped sized sensor and medium format systems Pentax should go ahead and bring out their FF camera. I am currently satisfied with my camera (K5iis) and the lenses I already have so it will make no differnce to me what Pentax produces however I do wish them success in the near and far futures and if producing a quality FF is part of the way forward GO FOR IT. The only downside I see is more lens equivanlency threads.
10-26-2015, 11:42 AM   #127
Pentaxian




Join Date: Nov 2013
Posts: 4,703
QuoteOriginally posted by osv Quote
get back to us when you have some experience with mirrorless cameras and adapters.
- First there no link with mirorless, this is the registration distance that count.
- Then the only difference between an extension tube and an adapter as a concept is that extension tube keep the same mount while adapter doesn't.
- Third some advenced adapters from Sony do have glass: the semi translucent mirror that is known among other things to reduce a bit the light that goes up to the sensor.

Last you are not able to get 2 time the same results in imatest, so even if you are a very experienced user of your camera, there no way you would be able to quantify any loss of quality from an adapter except if it is really huge and made the lense useless. We already know this isn't the case. On the topic your experience serve nothing but to look well in good company.

Sure I would not be able to do this anymore than you but that not the point here. We speak of the lens rental tests that recognized there to be among the best... That's a bit easy to keep here only what you like and say what you don't like doesn't exist.
10-26-2015, 12:38 PM   #128
osv
Pentaxian




Join Date: Mar 2007
Location: So Cal
Photos: Gallery
Posts: 2,080
QuoteOriginally posted by Nicolas06 Quote
- First there no link with mirorless, this is the registration distance that count.
wrong.

you have no experience with mirrorless, no experience with adapters, no experience with ff, and you haven't read what's been posted.

the only thing that you've done in this thread is make ridiculous claims, like telling us that "Sony ...have optimized the lense for the typical benchmark application" and "the smallest change in distance between 2 elements" wrt glassless adapters that don't even have any elements.

time to put you on ignore

10-26-2015, 12:54 PM   #129
Pentaxian




Join Date: Nov 2013
Posts: 4,703
QuoteOriginally posted by osv Quote
wrong.

you have no experience with mirrorless, no experience with adapters, no experience with ff, and you haven't read what's been posted.

the only thing that you've done in this thread is make ridiculous claims, like telling us that "Sony ...have optimized the lense for the typical benchmark application" and "the smallest change in distance between 2 elements" wrt glassless adapters that don't even have any elements.

time to put you on ignore
I look forward to it Unfortunately, I'm affraid this would just be a joke: you love too much to respond to other and defend Sony even with the most stupid arguments to do that...

But really do it, that's perfect for me
10-27-2015, 04:19 AM   #130
Junior Member




Join Date: Apr 2015
Posts: 33
QuoteOriginally posted by Another dyemention Quote
I won't keep talking in circles because I feel I made my point. I just feel like ricoh has a chance to be a much more "hip" and with-the-times company than the direction they are going. The ks-1 and ks-2 are good examples. Those cameras are new, they can appeal to the people who don't want a big professional looking dslr. People hanging out with their friends at dinner or a party. Who wants to bust out this big dslr with an 6" lens sticking out. Then have to wait to get home to edit it and share it. I'd love to snap some good quality pictures, edit them on my tablet already in my backpack, and get on with my day. Until I started shooting for money, I'd never have a need for more than that. Which is when if buy a ff anyhow.
I think that a big part of the problem here is what was said before: marketing and distribution.

I always research A LOT whenever I want to buy a product in order to get the best value for my money. So when I started looking into DLSR it was natural that I ended up with Pentax. But a lot of people don't bother that much. They decide they want a camera and then they want it today, not after weeks of research... so they go to a store, grab the first thing the sellers recommends and go home. Or they go to amazon, type in what they know (which is Canon or Nikon) and choose the camera that matches their budget. Getting these people to buy Pentax is no easy task: you have to be present at physical stores, you have to get the sellers in those stores to actually know the pentax line of products and recommend them to potential customers... and you have to be known enough so the customer doesn't get suspicious. And that's no easy task.

I remember that I went to a couple of bigger stores when I was about to buy the K10D. My impression was that I knew more about the different cameras then most of them did... and only a few of them mentioned Pentax before I asked, some of them even giving wrong information after that. I guess the situation hasn't change... and reversing this is not easy.
10-27-2015, 06:35 AM   #131
Senior Member
MMVIII's Avatar

Join Date: Mar 2008
Location: EU
Posts: 242
Beside the fact that the release of a professional model in the lineup does not minor the setup in the beginners section, which they cater with K-S2 and Q line, but why there seems to be the assumption that Ricoh is aiming mainly at professionals invested in Canon and Nikon?

Especially the quasi abandonment of DSLRs of Sony and Olympus may have left a bunch of people unhappy with these systems which much easier can find a new home in the Pentax system, having both the option to go compact with APS-C or top quality with 645. Either with K-5 size and limited lenses or 645 with high quality lenses, the K-1 can supplement both and thus might be the most versatile DSLR on the market, not to say, just a natural addition to the system.
10-27-2015, 12:36 PM   #132
Pentaxian




Join Date: Nov 2013
Posts: 4,703
QuoteOriginally posted by Barresian Quote
I think that a big part of the problem here is what was said before: marketing and distribution.

I always research A LOT whenever I want to buy a product in order to get the best value for my money. So when I started looking into DLSR it was natural that I ended up with Pentax. But a lot of people don't bother that much. They decide they want a camera and then they want it today, not after weeks of research... so they go to a store, grab the first thing the sellers recommends and go home. Or they go to amazon, type in what they know (which is Canon or Nikon) and choose the camera that matches their budget. Getting these people to buy Pentax is no easy task: you have to be present at physical stores, you have to get the sellers in those stores to actually know the pentax line of products and recommend them to potential customers... and you have to be known enough so the customer doesn't get suspicious. And that's no easy task.

I remember that I went to a couple of bigger stores when I was about to buy the K10D. My impression was that I knew more about the different cameras then most of them did... and only a few of them mentioned Pentax before I asked, some of them even giving wrong information after that. I guess the situation hasn't change... and reversing this is not easy.
I do like you, I make lot of research but this is far from easy.

When I brought my flat, I visited arround 25, checked the historic price, made similar to see how well it would resell in 5 year in I change my mind and so on... For most people it was crazy to do that much... Even if you engage yourself for a 20 years mortage and that a good investment or a bad investment can almost be the difference between wealth and poverty.

But time is the most precious thing in this world. We have a limited time there, we don't know how much. If you spend say 1 day of work (8 hours) spread over a few weeks to choose your camera, you could have been paid for a full day of work.and for many people that can be 200-400$ already. Imagine if you spend 2 days, that may be more than the price of the gear !

This could also have been time with the familly or simply for yourself... And there still the risk you didn't choose the best system for you anyway. This doesn't come with 100% success rate.

So while I tend also to analyse or over-analyse, the strategy to stay simple and choose fast one of the most well known manufacturer is a perfectly valid strategy too. In particular if you have less time than money or if you don't enjoy spending time comparings products...

Last edited by Nicolas06; 10-27-2015 at 12:45 PM.
10-27-2015, 06:58 PM   #133
Pentaxian




Join Date: Jun 2009
Location: GMT +10
Photos: Albums
Posts: 10,837
Back to the subject of this thread...

The quoted passage below is a pretty typical example of why Ricoh should be 'bothering with a FF'.

From the 'About' page of the web site of a talented local photographer that I stumbled across this morning:

QuoteQuote:
My first SLR camera was a film based Pentax MZ50 which allowed me develop an understanding of the staple photographic techniques required to be a professional photographer. I do miss the excitement of having my film developed and opening the packet at the lab in anticipation. I reluctantly progressed into the digital age with a Pentax K20D, which served me well and allowed me to experiment and develop my skills further. I have recently upgraded to a full frame Nikon digital SLR with professional standard Nikon lenses which allow me to produce high quality enlargements. My current kit comprises of the following:

Nikon D800E
Nikkor AF-S 16-35mm f/4G ED VR
Nikkor AF-S 300mm f/4D IF ED
Nikkor Micro 105mm AF-S VR f/2.8G IF-ED
Nikon 1.4x Teleconverter
Lee Filter System
Manfrotto Tripod
Sandisk Extreme Pro Memory Cards
Lowepro Camera Bag
Many Pentax customers see FF as a upgrade over APS-C that helps them deliver better, more professional results. If there was a Pentax FF around when he felt the need to upgrade, this photograpgher probably would have stayed with Pentax.

His comments also seem to reflect a common perception that 'professional standard' lenses are lacking in Pentax, because 'pro standard' glass is FF glass.
10-28-2015, 10:16 PM - 1 Like   #134
Site Supporter
kenspo's Avatar

Join Date: Mar 2014
Location: Oslo
Posts: 1,958
QuoteOriginally posted by Another dyemention Quote
I'm saying why bother catering to such a small percentage of professional photographers when you can cater to a much bigger crowd? The crowd that isn't yet photographers.
A few pros with FF's will attract more users for lower end cameras and generate more sales in general. Stop thinking so much, and let the people who know what they talk about, run the ship!
10-29-2015, 01:34 PM   #135
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Oregon
Photos: Gallery | Albums
Posts: 10,770
QuoteOriginally posted by kenspo Quote
Stop thinking so much, and let the people who know what they talk about, run the ship!
Hey Kenspo, after the change and delay of things at Ricoh regarding the FF camera, you seemed a little upset. I know you can't give any details, but I wanted to ask: Are you now happy again? I think as long as Kenspo is happy, I WILL be happy eventually.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
24x36mm, camera, cameras, canikons, car, care, dslr, fashion, ff, full-frame, game, image, iq, issue, leader, lenses, mf, mirrorless, nikon, offer, pentax, people, pixel, ricoh, shift, sony, tab
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Give it a try...? Why bother? AbadPhotography General Photography 123 11-26-2014 03:50 PM
K-30...Bother with the Kit lens at all? fantasysage Pentax SLR Lens Discussion 23 09-12-2012 05:19 PM
FF even with MF lens LightMeter Pentax K-r 7 11-19-2011 10:34 PM
What's with the FF Postings - Why ? wll Pentax News and Rumors 249 05-14-2009 07:59 AM
Why the Obsession with Full Frame (FF) DSLRs fwbigd Pentax DSLR Discussion 31 02-05-2008 08:27 AM



All times are GMT -7. The time now is 02:44 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top