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12-13-2014, 01:54 PM   #106
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The only issues for me with the D810 are the AMP GLOW problem (which also plagues the D800/E cameras) and the weight and cost of telephoto lenses . Initially, I thought they'd fixed the amp glow issue until my D810 had to be tweaked at a service centre to get rid of some image artifacts under certain conditions, but I noticed it was still there after the service. You can't push the shadows on a D810/D800 model as much as a K-5 (or even a K01) without the image showing a crimson cast. This is not an issue for normal exposures however, only when pushing the shadows hard in LR.

The 150-600 Sigma glass weighs a substantial amount and, if that is actually you in your avatar, I'd recommend staying with APS-C for telephoto work. My Sigma 120-300 weighs a similar amount and is very hard to walk around with after awhile, even with a Black Rapid strap. The Tamron 150-600 weighs a lot less but it's pointless buying one of those for a 36MP camera due to the lower resolution.

The previous suggestion of using a D810 for the wide angle to standard range and APS-C for telephoto is worth considering IMO.

---------- Post added 14-12-14 at 07:27 AM ----------

QuoteOriginally posted by Digitalis Quote
I use the D800E,Canon 1DsMK III, Leica M9, Leica monochrom, Leica S2, Pentax 645D, Phase one iQ180, Sinar 4X5 and Ebony 8X10 - I still use my APS-C pentax cameras. The Pentax K system is the only APS-C system I work with, I gave up on reduced format Canon and Nikon cameras ages ago.

FYI: I still use my pentax cameras for commercial macro work because there is really nothing else on the market that can match the FA*200mm f/4 ED MACRO when it comes to image quality.
And here am I feeling guilty for having a few brands and too many D800's.

12-13-2014, 02:02 PM   #107
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QuoteOriginally posted by bossa Quote

And here am I feeling guilty for having a few brands and too many D800's.
Ya, that's one of his main jobs around here, if the wife ever complains about what I've got, I'll show her what he's got and claim I need so much more to compete. If it wasn't for him I'd feel a lot less secure.

QuoteQuote:
The previous suggestion of using a D810 for the wide angle to standard range and APS-C for telephoto is worth considering IMO.
It's always been a plan on my radar, except for the part where I go back and forth between a Pentax FF at 36 MP should they release one, and a 645D second hand. With the 24 MP K-3 there is a lot less need for either.
12-13-2014, 02:14 PM   #108
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QuoteOriginally posted by Ian Stuart Forsyth Quote
With the D800 I primarily use the 200-400 F4 VrII, a borrowed 300 F2.8 VrI, 70-200 F4vr for wildlife







And seeing as you asked for some MF photos in another thread here’s an old 645n posted on photonet sometime ago

I was scanned by Scott sometime ago for me
Thanks for posting these wonderful shots Stuart. I doubt my Sigma 120-300 f2.8 Sports could match that 1st shot. Was that shot taken with the 300/2.8?

Cheers
12-13-2014, 02:38 PM   #109
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QuoteOriginally posted by bossa Quote
Thanks for posting these wonderful shots Stuart. I doubt my Sigma 120-300 f2.8 Sports could match that 1st shot. Was that shot taken with the 300/2.8?

Cheers
I think I posted the link to his website which is also very nice, if look back up far enough.

12-13-2014, 02:40 PM   #110
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QuoteOriginally posted by normhead Quote
Ya, that's one of his main jobs around here, if the wife ever complains about what I've got, I'll show her what he's got and claim I need so much more to compete. If it wasn't for him I'd feel a lot less secure.

It's always been a plan on my radar, except for the part where I go back and forth between a Pentax FF at 36 MP should they release one, and a 645D second hand. With the 24 MP K-3 there is a lot less need for either.
I do use my D800E/D810 cameras in crop mode a far amount of the time for telephoto work. That's 15.3MP IIRC.

IMO A 400mm lens on APSC would be a desirable combo for wildlife shooting. The weight of super telephoto lenses is a prohibitive factor to casual use - it's taken me awhile to work out where I sit - and I would have been saved a lot of money and physical discomfort if Pentax had a 400mm lens in their stable.

Last edited by bossa; 12-13-2014 at 02:51 PM.
12-13-2014, 02:57 PM   #111
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QuoteOriginally posted by bossa Quote
I do use my D800E/D810 cameras in crop mode a far amount of the time for telephoto work. That's 15.3MP IIRC.

IMO A 400mm lens on APSC would be a desirable combo for wildlife shooting. The weight of super telephoto lenses is a prohibitive factor to casual use - it's taken me awhile to work out where I sit - and I would have been saved a lot of money and physical discomfort if Pentax had a 400mm lens in their stable.
Amen !
12-13-2014, 06:13 PM   #112
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Great now we are on a new page without unsolicited oversized sample images clogging bandwidth...

QuoteOriginally posted by bossa Quote
And here am I feeling guilty for having a few brands and too many D800's
Never feel guilty about the things you enjoy in life.

QuoteOriginally posted by normhead Quote
Ya, that's one of his main jobs around here, if the wife ever complains about what I've got, I'll show her what he's got and claim I need so much more to compete. If it wasn't for him I'd feel a lot less secure.
HA!


Now I have used the crop mode on my Nikon D4s - I rarely use it because of the low resolution, but I never have to change the exposure when this mode is active - contrary to what Ian Stuart Forsyth states. Reducing the problem down to simple numbers is a hopeless task as there are so many variables in imaging systems, taking them all into account is practically impossible (even DXO can't handle it). 44 photons per unit of area; keep in mind that some of those photons aren't even going to make it to the sensel, some photons will smack into the wall for the sensel well without being recorded, some photons are going to be internally reflected off the surface of the sensor, and some photons are in the IR/UV wavelength and will be blocked by the UV/IR cut filter. IF we follow your model: The uncertainty principle favors the smaller format because there are more photons striking the surface(100 Vs 44) - statistically, the smaller format has a higher SNR. That isn't right, larger formats have Higher SNR because of the greater area of the sensor and the cumulative photon well capacity - this has an impact on image quality, but not upon exposure: ISO, f numbers and shutter speeds required for a target reflectance of 18% grey, IF all aspects of the imaging system are identical: exposure will be the same from APS-C to 8X10 format*.

* though mounting a 300mm f/5.6 designed for 8X10 format on an APS-C format DSLR would be a challenge.


Last edited by Digitalis; 12-13-2014 at 06:51 PM.
12-14-2014, 08:37 PM   #113
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QuoteOriginally posted by normhead Quote
Show me where the "Virtual ƒ4 " setting on your camera is?

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.

So do you understand what I've done there to make this point?

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
so according to your theories a D810 & D7100(K3) have the same low light/high ISO characteristics ?? as pixel density is the same..but then the D750 would be better as larger pixels,yes...from D4S 16 to 24 is not so great as sensor tech has improved alot. But if the D810 was shot at 16Mp or lower,wouldn't the high ISO's be cleaner?not sure how that works though
And from what some say the Tamron 150-600 is not good enough resolution for the D810's sensor
so the1st choice would be a D7100+Tamron if I need to have 600/900FL
note--there will be 50MP sensor out next year from Sony &?? so then the game changes I guess
12-14-2014, 08:55 PM   #114
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QuoteOriginally posted by Shanti Quote
so according to your theories a D810 & D7100(K3) have the same low light/high ISO characteristics ?? as pixel density is the same..but then the D750 would be better as larger pixels,yes...from D4S 16 to 24 is not so great as sensor tech has improved alot. But if the D810 was shot at 16Mp or lower,wouldn't the high ISO's be cleaner?not sure how that works though
And from what some say the Tamron 150-600 is not good enough resolution for the D810's sensor
so the1st choice would be a D7100+Tamron if I need to have 600/900FL
note--there will be 50MP sensor out next year from Sony &?? so then the game changes I guess
They have dramatically increased the DR of the 810, to about 15 EV, better than a K-5 even and as far as I know the DR on the D7100 and K-3 went back a stop to 13 EV. So , you are going to gain in DR going to an 810. So you do have that trade off. DO you want the DR or more resolution.

QuoteQuote:
And from what some say the Tamron 150-600 is not good enough resolution for the D810's sensor
If it's not good enough for the 810s sensor it's definitely not good enough for a D7100 sensor, but I'd take such info with a grain of salt. The D810 and K-5 are already suffering from diffraction in the red spectrum, but the blue spectrum won't top out until FF hits 100 MP. I guess we just have to wait to see what results are.

QuoteQuote:
there will be 50MP sensor out next year from Sony &?? so then the game changes I guess
The 51 will be equivalent to 24 on APS_c, but there's already 28 on APS-c. But yes, for a while the D800 and K-5, the K-5 was just a smaller version of the same technology. At some point the K-3 will also become just a smaller version of 51 Mp FF technology. It's that never ending technology thing. With all the talk of organic sensors etc, with a base ISO of 5200, and clean images up to 12,800 ISO, it's really hard to even guess where it will be in even five years.

I find the D750 and D4s to be quite interesting conceptually. But I'm also quite happy with my K-3 for the money. And I doubt I'd use either of them very much even if I owned them. My perfect world is K-3 for wildlife, 645z for landscape.
12-15-2014, 07:35 AM   #115
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QuoteOriginally posted by Ian Stuart Forsyth Quote
Just to clarify ( diffraction doesn’t scale with the sensor) what do you mean?
What I understand with diffraction is that its set by the VA or to make it simple, between formats if the images have the same DOF and FOV they will share the same level of diffraction the only difference is one format due to resolution limits may not capture it.
First, this is just about the technical part of a camera. I am not saying anything about any brands nor am I saying that FF is the only way to go.

Sensor size doesn't affect the size of the airy disk (aperture and lens design do). That means that an APS-C sized sensor needs an aperture of f4.0 to resolve the same amount of detail as a FF sensor at f5.6.

Given our current state of technology the APS-C sized sensor will expose flaws in production and lens design more than a FF sensor. (we have limited precision)
12-15-2014, 08:08 AM - 1 Like   #116
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QuoteOriginally posted by TrueFocus Quote
First, this is just about the technical part of a camera. I am not saying anything about any brands nor am I saying that FF is the only way to go.

Sensor size doesn't affect the size of the airy disk (aperture and lens design do). That means that an APS-C sized sensor needs an aperture of f4.0 to resolve the same amount of detail as a FF sensor at f5.6.

Given our current state of technology the APS-C sized sensor will expose flaws in production and lens design more than a FF sensor. (we have limited precision)
I'm not sure if I'm reading you right.. but I don't think that's exactly accurate. Saying we have limited precision... you might want to give us some evidence something from somewhere, there certainly isn't much evidence in the lens charts comparing different sensors on IR. The difference between a 24 Mp D600 and a 24 MP K-3 is about a 100 lw/ph when looking at a total lw/ph of about 2800, so well less than a 5% difference.

The diffraction is the same with the same lens no matter what format it's used on, but a 24 Mp APS-c will have much smaller Pixels sites. As with CA, the most efficient and useful way to describe diffraction would be as a fraction of pixel width. Once your diffraction (or CA) get's over 1 pixel, you have micro-contrast problems, once it gets over 2 pixels you have image degeneration problems. The smaller APS-c pixels will start to display diffraction issues sooner because the pixels are smaller for cameras with he same number of MP. Surprisingly then, both FF and APS-c appear, for the most part start to be diffraction limited after ƒ5.6, so while the point between 5.6 and 8 where the lens becomes limited is probably different, it makes no practical difference for the shooter. At first, the distances just aren't that noticeable. I know there is a measurable difference between ƒ5.6 and ƒ8 on my Sigma 70 macro, but the change in DoF is far more noticeable than the change in sharpness.

But if you check the IR images, you see, a K-3 resolves what a D600 resolves at ƒ5.6, and in many test images the K-3 images appear to be sharper because they have more DoF. You have to look in the image for the places where the D600 images are sharp, where as often the K-3 images are sharp pretty much through out the whole image. If you're shooting for more DOF, the FF noise advantage in terms of total light etc. is lost because you have to stop down to ƒ8 and shoot at a higher ISO to achieve the same DOF. That brings in both diffraction and more noise, making the FF and APS-c images roughly equivalent.

You have to be really careful when making overall conclusions based on a very narrow set of shooting circumstances. And be especially wary of the constant assumption made by FF propagandists, that narrow DoF is the preferred method of shooting and that APS-c "must" emulate it. In the real world narrow DoF is often the problem, not the solution cancelling any FF advantage.

If trying to keep everything in focus I'm shooting ƒ16 APS-c, I'd have to shoot ƒ22 FF, and the diffraction wold rather seriously affect the FF camera, going from ƒ16 to ƒ22. The APS-c camera is probably going to produce the best image.

Last edited by normhead; 12-15-2014 at 08:34 AM.
12-15-2014, 09:28 AM   #117
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Norm, that even makes good sense to me, and heaven knows I am not a technical soul by any means. Still, in the world of Toy Cameras, we just take what we get and don't worry much about how we got it.

Regards!
12-15-2014, 12:59 PM   #118
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Excellent discussion Norm - thanks.

I have a friend with a D800 who's also the co-owner of a gallery that i use. He complains his D800 gives too many blurry pictures, and he's considering a D750 to get larger photosites and more sharpness. Most sharpness tests are conducted on tripods, but most pictures are usually taken handheld. The problem being that with smaller photosites and handheld conditions, that a sharp contrast area can overlap too many pixels causing blurriness effects. Hope i said that right :-) Course its dependent on shutter speed as well. But in "real life" shooting, one doesn't have laboratory conditions and high pixel counts can make sharpness worse rather than better.

For the kind of shooting i do, i'm convinced that the only benefit that larger sensors have over smaller sensors is improved low light performance. And for a FF over an APS, thats about a stop of light. Here's a sampling of sports ISO's from the DXO database, i'm convinced that the "sports ISO" is a useful criteria for low light because it documents the highest ISO that provides minimum 30db SN and at least 9ev dynamic range. The A7s camera is one that really interests me because they rolled back the MP to provide superlative sensitivity across a wide dynamic range.

Here's a listing of "sports ISO" for some typical cameras:
1" sensor
Nikon 1 V3 384
Sony RX100 Mk3 495

Micro 4/3
Panasonic GH4 791
Panasonic GX7 718

APS sensors
Nex 6: 1018
Pentax K5 1162
Pentax K3: 1216
Nikon 7100 1256

FF sensors
Sony FF A7 2248
Sony FF A7R 2746
Sony FF A7S 3702
Nikon FF 610 2925
Nikon FF 750 2956
Nikon FF 810 2853
Nikon FF 4S 3074
12-15-2014, 01:45 PM   #119
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the advantage with 36mp comes when you are downsizing for printing... if you look at the dxomark comparison, using the "print" button, which equalizes both cameras at 8mp: Sony A7S versus Sony A7R - Side by side camera comparison - DxOMark

the only solid reason to get an a7s is for video, or if you are shooting at what, iso6400 or higher? which might be necessary inside one of those theaters.

when you compare 36mp vs. 24mp using the "print" button, you can see that every single aspect of pq improves with downrezzing, to the point where 36mp equals or exceeds the 24mp photo.
12-15-2014, 08:04 PM   #120
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QuoteOriginally posted by osv Quote
the advantage with 36mp comes when you are downsizing for printing... if you look at the dxomark comparison, using the "print" button, which equalizes both cameras at 8mp: Sony A7S versus Sony A7R - Side by side camera comparison - DxOMark

the only solid reason to get an a7s is for video, or if you are shooting at what, iso6400 or higher? which might be necessary inside one of those theaters.

when you compare 36mp vs. 24mp using the "print" button, you can see that every single aspect of pq improves with downrezzing, to the point where 36mp equals or exceeds the 24mp photo.
This is a picture i took in Oct 2011 for a play called Dracula:

[IMG][/IMG]
1/125s, f3.2, 20,000iso, Oct 2011, Pentax K5 (yep- thats 20,000 iso)

I once told the theatre director that she might consider using more light for the photographers to shoot by - the answer translated to something like "in your dreams". No flash allowed. We've been friends ever since :-)

I have a friend who luckily owns both the A7R and the A7S. He uses the A7S exclusively. he's not a video shooter - just single stills. Says he's not the only one using the A7S for stills.

The Sony A7s digital camera review. WOW. Period. | STEVE HUFF PHOTOS

There's a video link in Steve Huff's review of the A7S - says its the best all around camera he's ever had. Quite effusive review.

Its not just the low light shooting, its the low light focusing ability down to -4Ev, and its the only electronic shutter - totally quiet - of any FF i know. Its probably a crazy decision - but i want it!!!

Last edited by philbaum; 12-15-2014 at 08:21 PM.
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