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02-17-2015, 10:03 AM   #106
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QuoteOriginally posted by Wheatridger Quote
Cons-- Focusing really matters, with less DOF to hide errors. Ironically, it takes a better camera to take a blurrier picture! Also, telephoto lenses need to be longer and heavier for the same view. I think most of us will want to keep a K-5 or K-3 for tele work and devote the FF to wide and normal lengths. Cost and size of the FF camera, but I've counterbalanced that by choosing compact lenses and buying used.
.
I just wanted to mention that this FF use in wide and normal lengths is the market niche that Sony is exploiting so well. There is a significant, even large market segment out there that aren't going to want to buy the big tele lens, or carry them around - and i've seen the luggage carts that some FF'ers are using to carry their gear But for wide and normal length lenses, there is no signficant weight penalty in using a FF camera, particularly Sony downsized FF A7 series. I've handled these cameras and they are smaller and lighter than my K3. The first reaction i get when i report this is: Yeah, but how can you handle a large tele lens with the small A7 body. Thats the point guys, you don't buy A7 bodies to install a 600mm lens on.

QuoteOriginally posted by Wheatridger Quote
David-- Twenty or 30 years ago, I would have always wanted the fastest lenses available. Film speeds were much lower, and when you loaded a roll of ISO 200, that's what you were stuck with until 36 exposures were done. Many of my best opportunities happened in the afternoon or at dusk, too. So a half-stop of light was really precious.

Today, we can change ISO on the fly, crank it up three or four stops beyond what was possible with film, and clean up the noise in PP. So I see much less need for f1.4 primes and 2.8 zooms. In my Sony/Minolta system, I have a 50/1.7 prime (which you can buy used for about $50), and that's more speed than I usually need. But it all depends on your subjects and situations, too.
I don't think we'll see so many monstrously large tele lenses in the consumer market like there were in past years during the film era. Those lenses are really dinosaurs. Pentax's 150-450 is a really sharp move because its a popular size for teles, but also because it can be used with Pentax's stellar 1.4 converter to produce a 630mm FL. So if one really needs to use a FF for birding, one can carry the 150-450 and a small tele converter, and presto - your needs are covered.

So why are large tele's a thing of the past:
A. The low light/high iso capabilities of todays sensors, particularly the FF sensors. One generally doesn't need F2.8 zooms or primes when these high ISO's can make up the difference with very little penalty

B. People used to denigrate the use of RAM to zoom and crop into pictures. But i think thats what many of us are doing with today's high pixel cameras. So who really needs those really long lenses of film days, when one can easily crop down to the subject size with todays 16, 24, 36 or upcoming 50mp sensors???

C. EVFs and Liveview have allowed today's photographers an electronically magnified view for manual focus. This technique goes hand in hand with B. Even though one can enlarge a subject by cropping a ram image - one still needs that image to be "in focus".

I think all the discussions PF has had on FF sensors has not been wasted, A lot of us understand the subject better. As one who often shoots in dim playhouses, the chief advantage of FF sensors for me is low light capability. And you can go right down the sensor line with that. An aps sensor is better than a 4/3 sensor because of.... you got it - low light capability. etc. It's all about the light - and always has been.


Last edited by philbaum; 02-17-2015 at 12:53 PM.
02-17-2015, 10:26 AM   #107
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The low light advantage of larger sensors is relative to the individual pixel size. It is fascinating to me that Canon seems to be returning to pixel count as a marketing tool with the 50+ megapixel sensor recently announced. I cannot find any exact pixel details on those new sensors. But if you pack 50 million pixels onto a 24x36mm sensor they have to be smaller and likely less sensitive and probably more noisy than the individual pixels on APC size sensors having lower pixel density.
02-17-2015, 01:00 PM   #108
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QuoteOriginally posted by JeffB Quote
The low light advantage of larger sensors is relative to the individual pixel size. It is fascinating to me that Canon seems to be returning to pixel count as a marketing tool with the 50+ megapixel sensor recently announced. I cannot find any exact pixel details on those new sensors. But if you pack 50 million pixels onto a 24x36mm sensor they have to be smaller and likely less sensitive and probably more noisy than the individual pixels on APC size sensors having lower pixel density.
Not entirely true, the low light advantage of the large sensor is also due to the lower noise of the larger sensor.
02-17-2015, 01:26 PM   #109
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I disagree. Noise is related directly to pixel size, not sensor size.. Signal to noise ratio is increased and dynamic range decreased as the individual photoreceptor size is reduced. A sensor, (regardless of size) is simply an array of photoreceptors.


Last edited by JeffB; 02-17-2015 at 02:49 PM.
02-17-2015, 02:31 PM   #110
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QuoteOriginally posted by JeffB Quote
I disagree. Noise is related directly to pixel size, not sensor size.. Single to noise ratio is increased and dynamic range decreased as the individual photoreceptor size is reduced. A sensor, (regardless of size) is simply an array of photoreceptors.
all aspects of pq improve with downrezzing, including iso noise, so there are definite advantages to having more pixels.

you can see that on dxo, comparing the 24mp a7 to the 36mp a7r, using the "print" button, which scales both photos to an 8mp print.

the point that you are making is evident in the raw file view, which shows the a7 with a slight lead in iso performance... but things get completely flipped around after downrezzing.
02-17-2015, 03:45 PM   #111
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Speaking of "down-rezzing". I really enjoyed the picture quality I got from my old Nikon D1x. That used an ingenious in-camera down sizing method to combine the values of 2 neighboring photoreceptors into one pixel value. The color and dynamic range from that sensor was great. I am surprised that no other cameras (that I know of) have since used that design.
02-17-2015, 04:41 PM   #112
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QuoteOriginally posted by Rondec Quote
The whole high iso thing is a bit of a red herring. It does assume that you will shoot with a faster lens on full frame than is available on crop camera. If you need a certain depth of field for your image and have to stop down to get it on full frame compared to APS-C the high iso benefit will go away.
So, if I use my 50-135 @ f/2.8 on my K3, will the DOF be greater than the 70-200 @ f/2.8 with a FF camera, using the equivalent focal lengths? For instance, 50 on APS-C vs. 75 on FF, or 135 vs. 200.
02-17-2015, 04:48 PM   #113
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QuoteOriginally posted by JeffB Quote
I disagree. Noise is related directly to pixel size, not sensor size.. Signal to noise ratio is increased and dynamic range decreased as the individual photoreceptor size is reduced. A sensor, (regardless of size) is simply an array of photoreceptors.
Jeff, I think you're using some old information there.

A larger pixel will collect more light than a smaller pixel, but an array of smaller pixels over the same area will collect the same amount of light. You can reach a point where your individual pixel efficiency hits a wall if you make them too small, and that wall is always a moving target as sensor tech improves, but it's a myth that larger pixels are the reason FF sensors show better noise/DR performance.

Larger sensors perform better because they get more light from the lens used over a larger area. It's not directly related to pixel size.

See this link for a basic overview, or consider D800 vs. D7000/K5, which have the same size pixels of the same sensor generation.

---------- Post added 02-17-15 at 05:57 PM ----------

QuoteOriginally posted by MikePerham Quote
So, if I use my 50-135 @ f/2.8 on my K3, will the DOF be greater than the 70-200 @ f/2.8 with a FF camera, using the equivalent focal lengths? For instance, 50 on APS-C vs. 75 on FF, or 135 vs. 200.
Yes. There will be about 1.2 stops less DOF in the FF image at equivalent FOVs.

Or in other words:

50mm f/2.8 aps-c == 75mm f/4.3 FF in terms of both DOF and FOV.

.


Last edited by jsherman999; 02-17-2015 at 05:14 PM.
02-17-2015, 05:41 PM   #114
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QuoteOriginally posted by MikePerham Quote
So, if I use my 50-135 @ f/2.8 on my K3, will the DOF be greater than the 70-200 @ f/2.8 with a FF camera, using the equivalent focal lengths? For instance, 50 on APS-C vs. 75 on FF, or 135 vs. 200.
Yes. As Jay says, there will be the same depth of field at 135 f2.8 on APS-C that there is on a full frame camera shooting 200mm and f4 (roughly).
02-18-2015, 08:28 AM   #115
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The real advantage over apsc - IMHO - and it is something that dragged me at first place to FF is much i mean clearly noticeable better image quality, acuity if you like, if you compare the same lenses and apertures. The difference diminish however as you decrease the aperture hole. Long story short with FF you don't have to have superb optics as much as you do with apsc. With cheap lens or with low apertures image will be always better with FF - it doesn't register so many optics flaws as the pixel density is just lower. For example: two lenses FA*24 on apsc and FA35 on FF - i bet..., despite the same angle, image quality will be much better with FA35 and FF and despite the fact that FA*24 is more expensive and better optical quality lens... however on aperture say f5.6 or f4 the difference might be not so obvious as this is the region where both lenses present best image quality (sharpness etc I am not talking about aesthetic depiction here).
02-18-2015, 08:35 AM   #116
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QuoteOriginally posted by filorp Quote
The real advantage over apsc - IMHO - and it is something that dragged me at first place to FF is much i mean clearly noticeable better image quality, acuity if you like, if you compare the same lenses and apertures. The difference diminish however as you decrease the aperture hole. Long story short with FF you don't have to have superb optics as much as you do with apsc. With cheap lens or with low apertures image will be always better with FF - it doesn't register so many optics flaws as the pixel density is just lower. For example: two lenses FA*24 on apsc and FA35 on FF - i bet..., despite the same angle, image quality will be much better with FA35 and FF and despite the fact that FA*24 is more expensive and better optical quality lens... however on aperture say f5.6 or f4 the difference might be not so obvious as this is the region where both lenses present best image quality (sharpness etc I am not talking about aesthetic depiction here).
Are you going to show us some examples, or are you just going to talk?

I mean , honestly, I hear this kind of stuff all the time, but all the examples I've seen were with 10 year old APS_c technology compared to 5 year old Full Frame technology. Maybe it was at one time true, I'm not convinced, but maybe, I'm definitely not convinced it's true today, especially since in many cases, the camera have the same MP. Compare a D610 image to a K-3 image and in many ways, the K-3 images is better.

Last edited by normhead; 02-18-2015 at 08:42 AM.
02-18-2015, 08:57 AM   #117
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QuoteOriginally posted by normhead Quote
Are you going to show us some examples, or are you just going to talk?
unfortunately i can only talk now as i don't have any apsc any more but i still remember shocking discovery when i had k5 and d700 at the same time, the difference was immense.. i thought at first that Pentax lenses are simply inferior to nikon but when i put nikkors on k5 it showed just an opposite..... maybe it was user error maybe the fact that k5 AF system was something.... lets use euphemism: far from what you get use to on the market..... and by the way the only thing that kept me with Pentax was the three FA Limited musketers and 24*..... i know they are on the top....
02-18-2015, 08:58 AM   #118
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My experience was just the opposite of filorp. I used a 24x36mm "full frame" sensor before any APC models when I first switched from film to digital. With the Kodak 14n I found it exaggerated low quality optics especially in the corners. Since there weren't any lenses optimized for digital use back then there were real issue with light falloff and aberration at the edges of the sensor because of the angle light struck the sensor. I left "full frame" and starting using APC sensors because I was cropping off most of the extra image area being captured by the bigger sensor.
02-18-2015, 09:04 AM   #119
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Here's my dilly dallying on the subject..... blind tests often produce different results from people's personal opinions on the subject.

https://www.pentaxforums.com/forums/169-pentax-full-frame/270828-ok-guys.html
02-18-2015, 09:17 AM   #120
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