Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-10-2014, 07:30 AM   #76
Veteran Member




Join Date: Mar 2007
Location: Boston, PRofMA
Photos: Albums
Posts: 3,026
Another thought is FF for bokeh/wideangle and m4/3 for telephoto...
Enjoying my GH4 so far...

12-10-2014, 08:38 AM   #77
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 37,389
QuoteOriginally posted by kenyee Quote
Another thought is FF for bokeh/wideangle and m4/3 for telephoto...
Enjoying my GH4 so far...
For wide angle / landscape you really want a 645z.... One advantage of APS-c over 4/3 is you have the option to use all those Full Frame lenses with full AF and selective focus capabilities. If an FF guys says, "I have a 600mm ƒ4" you can always say.. "well I can mount that on my APS-c and it'll be like 900mm."
12-10-2014, 11:12 AM   #78
Pentaxian




Join Date: Feb 2010
Location: Northern Michigan
Photos: Gallery | Albums
Posts: 4,795
QuoteOriginally posted by zoolander Quote
My perception of color is not determined by my gender, thats not a valid argument and is sexist.
If it's "sexist," then reality itself is "sexist." Men and women do tend to see colors a bit differently. Here's the results of a recent study:

QuoteQuote:
In color experiments the men and women tended to ascribe different shades to the same objects. The researchers think they know why.



"Across most of the visible spectrum males require a slightly longer wavelength than do females in order to experience the same hue," the team concludes...


Since longer wavelengths are associated with "warmer" colors, an orange, for example, may appear redder to a man than to a woman. Likewise, the grass is almost always greener to women than to men, to whom verdant objects appear a bit yellower.

The study also found that men are less adept at distinguishing among shades in the center of the color spectrum: blues, greens, and yellows....


The team puts this advantage down to neuron development in the visual cortex, which is boosted by masculine hormones. Since males are flush with testosterone, in particular, they're born with 25 percent more neurons in this brain region than females, the team noted.
These findings accord with my own experience. I get many more compliments about the colors of my images from women than from men. In fact, it's like a 10 to 1 ratio in favor of the female gender.

But the broader point is that it's not only differences in color perception between men and women, but often between individuals, regardless of sex or ethnicity. Some individuals suffer from varying degrees of color blindness (often without knowing it). Aging can affect color perception. I knew a photographer who, after cataract surgery, noticed that all his images suffered from a yellow cast. Color is therefore subjective in the sense that not everybody experiences colors in exactly the same way.

QuoteOriginally posted by zoolander Quote
Those are two real world images by a real person. In the Pentax image, the snow in the middle of the train tracks look like ....... wait for it ..... snow ! the D800 image is all over the place and ugly. There's a huge diference there in processing engine and White balance.
Right, there is a difference in AWB and processing engine. But these kind of differences are easily fixed in post, even without tedious profiling. Just adjust the white balance in post and you're done. Differences in color representation as a result of different interpretations of data aren't that big a deal, as both cameras should be recording very similar sets of data. After all, both cameras are using the same sensor technology. So the only real differences would be the color renditions of the respective lenses which, with high end glass, tend to be pretty subtle.
12-10-2014, 01:00 PM   #79
Pentaxian




Join Date: Jul 2009
Location: Seattle
Posts: 9,465
QuoteOriginally posted by zoolander Quote
Are you sure you got those links correct? They don't seem to support your argument. The top one (D800) the snow is white by the post with the yellow #70 on it. The bottom link (K3) the snow is green/blue ish With so many mixed color temperature light in that scene, how can anyone judge snow color. It all depends where you look and what light source is on it. You can only WB on one area of the photo. That's a "real world" photo alright. Full of ambiguity.


Last edited by tuco; 12-10-2014 at 01:11 PM.
12-10-2014, 02:15 PM   #80
osv
Veteran Member




Join Date: Mar 2007
Location: So Cal
Photos: Gallery
Posts: 2,080
QuoteOriginally posted by normhead Quote
I choose to give up the advantages of FF, which are of very little use to me, to get the advantages of FF.
wot?

that makes about as much sense as "virtual f/4"
12-10-2014, 02:25 PM   #81
Veteran Member
Shanti's Avatar

Join Date: Jul 2012
Location: Western Denmark
Photos: Gallery | Albums
Posts: 925
Original Poster
QuoteOriginally posted by zoolander Quote
Look I don't own a D750, but I did once own a Nikon. I recently tried out a D7100 and D750, and the high ISO on the D750 was very impressive. But the D750 was designed to replace the D600 and D610, and the later did not have very good high ISO ability (There's a web review where the K-3 beats the D600 Nikon D600 vs. Pentax K-3 Image Comparison: Pentax Sweeps Nikon) Even when the D600 first came out, it got walloped by the Canon 6D for high ISO performance. But what is key in all of this, is that Nikon had the oil splatter problem with the D600, and were defeated in court in the U.S. But guess what, Nikons still have serious problems with oil splatter. Honestly, I had no idea how bad it was until a salesman at a local camera store told me about his D7000's problems, so I went home and googled it. There is a whole host of models with the oil splatter problem including the D750 ...... STILL ! and this was the model that was to solve Nikons woes over oil splatter. So just check online for further reports on which models are having the problem.

Anyway, high ISO is really impressive on the D750 - but you don't see me rushing out to buy one ! Its so cheap and tacky in the hand. The button layout is awful , and its not free flowing and ergonomic like a Pentax. But if you are left handed, you could easily live with it - its more of a lefty's camera (No offence to the communists and left handed people !) I think the D7100 and D750 share the exact same body and chassis, and its huge. For me the image quality in terms of colors is real off putting. Even side by side comparisons with Canon, shows that Canon has the color right (6D). The entry level tiers of Nikon have bad colors, as far as I'm concerned, but the top tier look very right........ But thats the product separation in Nikon.

Once you get the D750 or D810, you should make the decision then whether to sell your Pentax gear. Try renting a D750 for a couple of weeks to see if it works for you. But if its snowing or rain where you live you should keep the Pentax gear, because you simply cannot use Nikon gear in the wet, I've heard too many stories from people who have lost Nikons to light rain.

High ISO performance is all an illusion anyway, considering that the Fujifilm X-A1 matches the D750 in high ISO performance.
NOt had the chance to try a D750,no shops here have one!! have held a D800 for a short time & it felt almost as good as my E1 in the hand. No where to rent here either!! big pain but life in the countryside has its limits
find it hard to believe Nikon would cripple the D750 after all the D600 problems?? so it seems its best to use more $$ & go for D810 if I want oil free sensor & as price of oil has dropped recently,maybe even more will appear
I keep my Pentax..ya maybe you can pry from my 'cold dead hands' but I do like it
12-10-2014, 03:06 PM   #82
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 37,389
QuoteOriginally posted by osv Quote
wot?

that makes about as much sense as "virtual f/4"
I fixed it are you happy now?

12-10-2014, 06:58 PM   #83
Site Supporter
Site Supporter
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 10,228
QuoteOriginally posted by zoolander Quote
I'm saying you cannot invalidate my opinion by claiming men are less demanding over color accuracy, your using a sexist argument. Saying women are more demanding over color accuracy is pretty sexist.
I'm not claiming anything - I'm merely stating a fact. Is it simply a co-incidence many people who work in cinematographic colour corrections happen to be women? is it also a co-incidence that many graphic pre-press colourists are also women? If you can't handle a statement that I have made through my own experience (and experience of others) that then that's your trip. Women have had to jump through enough hoops over the centuries to be accepted as equal to men - Many of the blatantly unfair aspects of this has been undone, we still have a way to go. But no matter how far we get there are always going to be differences between the sexes, I suggest you get used to it.

QuoteOriginally posted by zoolander Quote
The Canon wins it, but the large Blue material on the barge is very blue in the Nikon shot.
On my monitor the colours between the two cameras are basically the same - the only thing that has changed in the image is the overall white balance differential: The canon was warmer, the Nikon camera was set at a colder temp, this will amplify the appearance of blues in the image. If both cameras were set to 5000K they would look pretty much identical. The Canon camera doesn't win anything.

QuoteOriginally posted by zoolander Quote
Lower tier 35mm and all apsc Nikons have wrong colors. Whether this has to do with white balance or the processing engine, both are out for the purpose of ......... model separation into price segments. The higher you go up in price, the more accurate the colors and white balance become.
Are you suggesting there is a manufacturer conspiracy on colour accuracy? can someone pass me my tin-foil hat? IF you work with a colour calibrated workflow and with the same lenses: the differences in colour rendering between cameras become extremely small*. Many consumers are unable to calibrate image capture processing workflows and LCD displays - despite the technology being mature and readily available. If people complain about colour accuracy and do nothing about it - they are just complaining just for the sake of it. IF you don't like the colours from your camera, calibrate your workflow and develop your images they way you want them to look - it really isn't that hard.

QuoteOriginally posted by zoolander Quote
DPreview has shown itself to be biased a very long time ago.
And so have you. Incidentally, did you get that completely unnecessary UV/IR cut filter for your DSLR?

* and I work professionally with a wider variety of cameras than anyone else on these forums.

Last edited by Digitalis; 12-10-2014 at 07:16 PM.
12-10-2014, 10:37 PM   #84
Pentaxian




Join Date: May 2009
Location: Somewhere over the rainbow
Photos: Gallery
Posts: 1,001
QuoteOriginally posted by Digitalis Quote
nice, you now have too well exposed images of an X-rite colour checker.

My issue with your earlier comments was your use of the term "virtual aperture" I think you meant equivalent aperture.
I like to use virtual aperture while other like to use the term (entrance pupil)
The hole point of the exercise is to show that you can have 2 different exposures but when those exposures are across format they can capture the same total light.
Thus demonstrating that the total light in an image is what determines the level of the noise in an image and not the exposure value between formats
12-10-2014, 11:45 PM   #85
Site Supporter
Site Supporter
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 10,228
QuoteOriginally posted by Ian Stuart Forsyth Quote
I like to use virtual aperture while other like to use the term (entrance pupil)
I prefer entrance pupil because it is commonly referred to in optical literature, virtual aperture implies something that isn't real. Where the entrance pupil has very real, physical properties.

Last edited by Digitalis; 12-10-2014 at 11:51 PM.
12-11-2014, 12:13 AM   #86
Pentaxian




Join Date: May 2009
Location: Somewhere over the rainbow
Photos: Gallery
Posts: 1,001
QuoteOriginally posted by normhead Quote
Show me where the "Virtual ƒ4 " setting on your camera is?
was corrected to a virtual of 75mm

QuoteOriginally posted by normhead Quote
With APS-c shooting from a given position, and equivalent lenses you get more DoF with APS_c . The sharpest part of the lens is usually about ƒ5.6. To get "virtual ƒ5.6" on FF I have to go to ƒ8, and by ƒ 8 a lens is already becoming diffraction limited (on FF or APS_c), so even though I've stopped down to gain DoF I've lost resolution to diffraction.
If FF and aspc share the same DOF in both images they will also share the same level of diffraction in both images
So if I see diffraction on a FF at F8 ( your figure) then I would see the same diffraction at the equivalent APSC F 5.3

Let’s take very commonly used lenses 50-135 F2.8 on cropped and 70-200 F4.0 on FF
Both lenses wide open will have the same DOF and Total light
Both lenses stopped down 2 stops will show the same level of diffraction and capture the same total light and same DOF
With a very little weight and cost penalty in the lens. But with FF under most light conditions you gain more DR and better SNR





QuoteOriginally posted by normhead Quote
First, I defined "virtual ƒ 5.6" in terms of APS-c instead of FF. Then I've defined "normal" as wide DoF, instead of narrow DoF, shifting the advantage to APS-c instead of FF. Then, I've defined a situation, shooting at ƒ5.6 on APS_c as the "ultimate goal". Then I've pointed out the problems you face shooting that "normal" on FF.

So in essence, what I've done is, I've done for APS-c what you did for FF. And the argument is just as compelling and just as erroneous.



The argument for FF is more resolution in some camera bodies, less DoF, if that's what you want, and better low light performance, although light so low it makes a difference ruins your dynamic range in any case. But as soon as you have a situation where you want more DoF and don't need to blow your image up to 96x48, you've actually crippled yourself going FF, in terms of weight and the size of the lenses you'd have to carry. To match the resolution of your subject you achieve with APS_c you'd have to have a 51 MP D810.


You choose to give up the advantages of APS-c to get the advantages of FF. I choose to give up the advantages of FF, which are of very little use to me, to get the advantages of FF. But no where in my thinking do I imagine that one system is in some way "better". They both have advantages over the other.

You should check out this thread.... if you check out the images objectively, you might understand there are circumstances where you aren't using the best equipment for the job. You might want to add a D7100 to your camera bag...until 51 MP FF is available. But 28 MP APS-c is already available, so even that won't really cut it.
https://www.pentaxforums.com/forums/122-lens-clubs/55946-300mm-plus-lens-club...enses-973.html
you don't gain the additional 9MP of resolution when moving up to from 15-24 its more around maybe a additional cropping ability of 1.2 max and that at base iso once you move up beyond Iso 400 you gain nothing
For a 36mp FF all one would have to do is increase the FL by a factor of 1.2 so a 300mm you would need a 360mm one could pickup the sigma 120-400 4.5 -5.6 and still retain the level of sharpness of the da 300 F4 and give you better resolution for cropping
Even the 150-500 with the D750 would give you a very competitive performance and before you say well its not very good you have to remember that the photo site cells on the D750 are just a little smaller than the photo sites on the K10d so the lens would not have to resolve as much.
That's what makes FF so attractive, for a ASPC lenses with the same FOV and DOF control as the FF counterpart it has to resolve 1.5 times more resolution just to play catch up
We can have a moderate zoom like the 70-200 F4 at 150mm wide open and give us better performance than a prime lens of the equivalent cropped FOV and way more cropping ability
12-11-2014, 02:52 AM   #87
Site Supporter
Site Supporter
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 10,228
QuoteOriginally posted by Ian Stuart Forsyth Quote
Let’s take very commonly used lenses 50-135 F2.8 on cropped and 70-200 F4.0 on FF Both lenses wide open will have the same DOF and Total light
No - they won't because at ISO 100 1/500th, with both lenses wide open: the f/2.8 lens is letting in more light than the f/4 lens is. DOF will be similar but the intensity of light at the focal plane remains unchanged in relation to format T=2.8 is absolute*. Just becasue the light is being spread out more doesn't mean that there is greater intensity at the focal plane - actually, there will be slightly less light hitting the bigger sensor due to the sensor not being able to handle oblique light rays** and the effects of mechanical and optical vignetting.

*assuming the same lensmount flange distance, focus distance and the lenses are identical, and optically transmit 100% of the light.
**this is a big problem with many fast lenses with focal lengths 50mm and below.

Last edited by Digitalis; 12-11-2014 at 03:00 AM.
12-11-2014, 05:05 AM   #88
Site Supporter
Site Supporter
Cynog Ap Brychan's Avatar

Join Date: Sep 2012
Location: Gloucester
Photos: Gallery
Posts: 1,196
http://youtu.be/YDbUIfB5YUc?list=PLBE338967F8DB7F2A

With respect to using FF lenses on crop bodies, this video is quite informative, though I don't agree with it 100%
12-11-2014, 06:50 AM   #89
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 37,389
QuoteOriginally posted by Ian Stuart Forsyth Quote
I like to use virtual aperture while other like to use the term (entrance pupil)
The hole point of the exercise is to show that you can have 2 different exposures but when those exposures are across format they can capture the same total light.
Thus demonstrating that the total light in an image is what determines the level of the noise in an image and not the exposure value between formats
An interesting classroom construct of very little use in the real world. I find noise is variable depending on shooting conditions in all ISOs. Without defining what the cut off point is for a given situation, which is the only possible thing it cold be used for, it tells you nothing useful.

Now if you're claiming that by using a terms such as "Virtual aperture" you are defining something useful, fine, tell me how you use it in every day shooting, or what use it is at all? As I said, and you of course ignored me, as is usually done with all useless stuff, just ignore the question...

Where is the setting on my camera for "virtual" aperture? I can set the aperture on my camera. I can set the shutter speed. I can set the ISO. I can't set the "virtual aperture". There's no control for that.

The whole concept of virtual aperture is wrapped up in a few simple statements. Larger sensors collect more light. If noise is an issue, consider trying out to a larger sensor. What noise is acceptable to you personally is a personal preference for the most part, not determined by formula. You can achieve that by taking a few hundred images with your camera. "Virtual aperture" is a totally unnecessary concept. Unless of course someone would like to take the time to test every camera ever made and demonstrate empirically what it's real world results are for each camera compared to some "virtual aperture." That's what amuses me most about this type of concept. People will swear up and down that they are talking about something real, but don't put the time in to prove it.

A proof requires empirical confirmation of the theoretical construct, in every conceivable situation. Exceptions must be documented and noted. Without that documentation, it's not proved.

The only thing you can prove with a "virtual aperture" would be what "virtual noise" you might have. Talking about "virtual aperture" without endless papers in the sensitivity and characteristics of every sensor out there is non-sense. Or should I say "virtual nonsense" ? That's like talking about grain without talking about the size of the silver halide crystals. It's reducing a complex interaction of signal, amplifiers, encoders and processing software into one parameter, the total light on the sensor. Without understanding the affect of total light on the whole process, it means nothing. Without understanding the different sensitivities of different sensors, it means nothing. Without understanding the effect of the signal amplifiers it means nothing, and without understanding the effect of any built in noise reduction software, it means nothing. Without understanding the sensor's response to contrast and dynamic range, it means nothing.

Or in short, it means nothing.

Last edited by normhead; 12-11-2014 at 07:10 AM.
12-11-2014, 06:54 AM - 1 Like   #90
Veteran Member
Otis FanOtis FanOtis FanOtis FanOtis FanOtis Fan
Rupert's Avatar

Join Date: Sep 2006
Location: Texas
Photos: Gallery | Albums
Posts: 25,123
Still enjoying this thread, and still learning a little ........did enjoy the video of FF lenses on crop bodies...very interesting!

I want to interrupt this thread with a brief 30 second Commercial and then let you guys get back to the more technical discussions.

Ever get the feeling that all this high tech stuff is just too complicated? Does your wallet feel weak and empty from trying to keep up with the latest advances in bodies and lenses......is your wife threatening divorce because your utilities have recently been interrupted due to the expense of that new gear? Do you stay awake at night wondering how to pay your bills and get the gear you "desperately need" and also vow to post a better shot than that guy who is constantly posting masterpieces with his FF camera?

Well, fellow shooters, there is relief and it's right here at PF! Drop all that high priced gear and join us in the Toy Camera Thread where you will be welcomed with open arms and can post without fear of injury or insult! All brands are welcome, you can save a fortune, and your wife won't leave you! You will find joy and immense pleasure at always having a camera in your hand...or shirt/jacket pocket, and seldom missing an opportunity to capture what those "Big Boys" are missing.

Just step out of your pew seat, walk down the aisle, and join the Toy Shooters today! Salvation is just a click away! It will lift the load off your troubled mind and your body too...all those big cameras and lenses are really heavy! Don't hesitate, just click now and find freedom and joy with others that have given up the fight and found true happiness!
https://www.pentaxforums.com/forums/76-non-pentax-cameras-canon-nikon-etc/257...fess-here.html

This message brought to you by the Toy Camera Shooters at PF and paid for by Old Rupert.

Best Regards! & hope to see you soon!
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!
body, camera, cls, color, colour, colours, compensation, d610, d750, d810, event, ff, flash, gear, glass, iso, k5, k5ii, lens, love, nikon, noise, pentax, pentax gear, people, range, retention, review, tamron 150-600, tool
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Nikon D750 Winder Non-Pentax Cameras: Canon, Nikon, etc. 535 06-18-2015 08:29 AM
Pentax should consider copying the D750 MJSfoto1956 Pentax Full Frame 57 09-26-2014 02:35 PM
NCN :The Shocking Truth Behind The Pentax 645z wtlwdwgn Pentax Medium Format 19 04-23-2014 04:43 PM
Paul Krugman dares to tell the truth boriscleto General Talk 1 09-13-2011 03:32 PM
Bigma Owners please tell? vievetrick Pentax SLR Lens Discussion 11 03-21-2008 07:28 AM



All times are GMT -7. The time now is 04:18 PM. | 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