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03-12-2017, 07:34 PM   #16
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QuoteOriginally posted by normhead Quote

So essentially, when shooting a 24 MP full frame, and a 300mm lens ƒ2.8 , and a 24 MP APS-c with a 200mm ƒ 2.8 lens, you will have the same field of view and same resolution.......... That's why people say the APS-c gives you more reach.


The point I was trying to make was that it is not the format (aps-c) that gives an apparent "greater reach". In your example the 24mp aps-c camera has a much higher pixel density than the 24mp FF. If we assume that all pixels are created equal (and they clearly are not as you demonstrated in your post), then it is the pixel density which is giving the aps-c camera extra reach and equal resolution, not the format. For example would you say the same above if you substitute my old Pentax DS 6mp aps-c camera ?

I agree in practice it is probably just semantics

03-12-2017, 08:43 PM   #17
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QuoteOriginally posted by normhead Quote
So essentially, when shooting a 24 MP full frame, and a 300mm lens ƒ2.8 , and a 24 MP APS-c with a 200mm ƒ 2.8 lens, you will have the same field of view and same resolution, in essence, identical images. Both will suffer the same amount of enlargement to print them big. That's why people say the APS-c gives you more reach. What's the difference You ask? Well it's the difference between this and this for the same image. We are talking a 3 pound total package against an 8 pound total package. One manageable one not.
This is not a comparison that demonstrates that FF is heavier than cropped, it’s a comparison that one system with a larger shooting envelop is the heaver of the 2.
If you want a fair comparison why not look at the weight of the K1 along with the 300mm F4.5
1945g
To the K3II and the 200 f2.8
1625g
Not so much of a difference
If it is your goal is to carry a single lens with the desired 8 degrees of FOV while still having the ability for unexpected cropping when you need it . The K1 with 36mp with a 400mm F4.5 lens will give you more room for cropping than the K3II and 200 F2.8.
03-13-2017, 06:12 AM   #18
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QuoteOriginally posted by Ian Stuart Forsyth Quote
This is not a comparison that demonstrates that FF is heavier than cropped, it’s a comparison that one system with a larger shooting envelop is the heaver of the 2.
If you want a fair comparison why not look at the weight of the K1 along with the 300mm F4.5
1945g
To the K3II and the 200 f2.8
1625g
Not so much of a difference
If it is your goal is to carry a single lens with the desired 8 degrees of FOV while still having the ability for unexpected cropping when you need it . The K1 with 36mp with a 400mm F4.5 lens will give you more room for cropping than the K3II and 200 F2.8.
I use fast glass only for shutter speed when I need it and to improve my auto-focus performance.. Depth of field equivalence is not a concept I care about one iota. I almost always expose for maximum resolution expressed as lw/ph and maximum depth of field. That means ƒ5.6 on most and APS_c and Full Frame lenses, although with the best lenses it can be ƒ4 and even lower. The only time I shoot a wider aperture is when low light forces me to. And in those situations ƒ4.5 is much worse than ƒ2.8. FF is a little more tolerant maintaining lw/ph going to ƒ8 than APS-c is, so I often shoot ƒ8 on FF. It maintains both maximum DoF and maximum lw/ph, without seriously crippling my shutter speed in bright sun. In shade ƒ4 and even sometimes ƒ2.8 become necessary to prevent subject motion blur.

So, no ƒ4.5 on FF is not ƒ2.8 on APS-c. AF systems are usually calibrated for ƒ2.8, on both FF and APS-c systems. To get the most out of your AF you need ƒ2.8 glass in many cameras, and all Pentax systems as far as I know.

I say this for any who might be reading. Ian thinks differently. I've been through this with him many times, and he remains stubborn in his opinion. I wouldn't expect him to change now, so expect a response explains how wrong I am, that ignores, that sensors are tuned for 2.8 AF, that Aperture refers to the intensity of light transmitted, not depth of field, and that shutter speed is a big factor in selecting ƒ2.8 glass for wildlife and birds in flight.

He will argue that the only important aspect of aperture is depth of field. Or maybe he won't since I've already explained his point.
03-13-2017, 06:42 AM - 1 Like   #19
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QuoteOriginally posted by normhead Quote
Depth of field equivalence is not a concept I care about one iota.
Over the years the 'Depth of field equivalence' is always used as some sort of defining argument in the difference between the two formats. As far as I recall I can't remember anybody explaining why it is considered so important unless one is trying to make an exact copy of a scene.

03-13-2017, 07:23 AM   #20
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QuoteOriginally posted by mohb Quote
Over the years the 'Depth of field equivalence' is always used as some sort of defining argument in the difference between the two formats. As far as I recall I can't remember anybody explaining why it is considered so important unless one is trying to make an exact copy of a scene.
I don't even like to make exact copies of my own photographs, forget about someone else's. You take the optimum photo for the format you use. What someone else is doing on a different format is irrelevant. Which format is more appropriate to the scene is completely a crap shoot. But given that most of us only carry one or two formats, odds are, we are using something less than the optimum format most of the time. We just pick our poison and live with it.

The " FF is the greatest thing since sliced bread" with all the justifications about narrow DoF resolution etc, arguments were a great disservice to photography. People who really know photography will be able to expand upon the strengths and weaknesses of every format and explain their place on a continuum in various categories, resolution, low light performance, weight, DoF ( meaning wide, as well as narrow DoF) etc. You own't find them going on about one format being "better" than another. To do so, you have to ignore an awful lot of reality. One might be better in one small area, but it's not going to be better in all of them.

Last edited by normhead; 03-13-2017 at 07:37 AM.
03-13-2017, 11:16 AM   #21
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QuoteOriginally posted by normhead Quote
Personally, APS-c is my favourite compromise, but my most used camera is the K-1, and i would buy them in that order.
Why is the K-1 your most used camera, if it is ranked second after APS-C?
03-13-2017, 12:13 PM   #22
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QuoteOriginally posted by leekil Quote
Why is the K-1 your most used camera, if it is ranked second after APS-C?
The K-3 is better at landscapes than the K-1 is at doing birds and wildlife. If it came down to what I'd miss most it would be the fast frames per second rate, but more importantly the 23 shot buffer, and the speed at which the buffer is cleared. For small birds and wild life those things are really important. 3600 lw/ph instead of 2700 lw/ph is barely noticeable in most images.I never print more than 20x30. 90 distinct line per inch using a K-3 or 120 distinct line per inch using a K-1. It will be barely noticeable in most photos. In fact we have trouble telling the difference between the difference between a K-5 and the K-1 in everyday images. 1/90 is .0111. 1/120 is .0083. .0111-.0083, is .0028, or approximately 3 thousandths of an inch. It's amazing how many people think that will make a huge difference to an image. From 5 feet, you can't even see .003 of an inch.

You get slightly less quality with a K-3, but you get a lot of images you won't even get with a K-1. And I swear the K-3 clears it's 23 shot buffer faster than the K-1 clears it's 8 shot buffer, although maybe it just seems that way, because you rarely fill the K-3 buffer, but I consciously slow my frame rated down to probably about 2 frames per second with the K-1 to avoid filling the buffer. To many times I've sat there and watched as good images went by, waiting for my buffer to clear. It's a big performance hit. The K-1 has some advantages to be sure, but for me they don't make up for it's shortcoming in speed.

But when I'm out on a hike doing maybe landscapes or sunsets or whatever, I don't need the high frame rate and the superior Dynamic range, better high ISO performance, superior resolution and many other features, make the K-1 the one to have. But my K-3 is still in the holster with the DA*200 with the 1.4 on it and the 1.7x close by, incase I need reach and speed.

It's just a question of what you are prepared to live without. And I can see 99% of the Pentax shooters, making the opposite choice. It's all about what makes you happy. Reality says, you get many more photo ops for stationary objects than you do for living, moving targets. For stationary targets the K-1 and 28-105 is an amazing combo. But for the difference it makes, I won't give up the other things that the K-3 has that the K-1 doesn't. Speed, and magnification.

I did say the K-1 gets more use. I spend more time with it in my hands, but out in the blind shooting the little birds or in the park shooting wildlife, I may shoot 500 images in a single session. I'll spend a lot of time with a K-1 in my hands before I get 500 images. 60-120 per session is the average.

As I said previously, you need both.

Last edited by normhead; 03-13-2017 at 12:31 PM.
03-13-2017, 03:31 PM   #23
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Since we want to elaborate on the subject. The key reference feature in a camera is the pixel pitch. The more pixel you have the larger is the sensor, but everything related to resolution, i.e. DOF, is related to pixel pitch. Angular coverage per pixel is a function of focal length and pixel size.
With a correct idea on pixel pitch you can understand why a 300 mm lens in MFT format has great magnification power, but resolution per pixel is limited due to its tiny size. Similarly the signal to noise concept is a function of pixel dimension.
What really sucks in APS-C vs. FF discussions is that all K-mount lenses are designed to fit FF DSLR light paths - the mirror of a fullframe camera still goes up and down. The image circle may be less than fullframe, but the rear lens element has to be further away than it would have to be. This is troublesome for wideangle lenses as you will end up with more glass and distortion than necessary. For tele lenses there is no disadvantage.

03-13-2017, 06:04 PM - 1 Like   #24
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QuoteOriginally posted by zapp Quote
Since we want to elaborate on the subject. The key reference feature in a camera is the pixel pitch. 1. The more pixel you have the larger is the sensor, but everything related to resolution, i.e. DOF, is related to pixel pitch. 2. Angular coverage per pixel is a function of focal length and pixel size.
With a correct idea on pixel pitch you can understand why a 300 mm lens in MFT format has great magnification power, 3. but resolution per pixel is limited due to its tiny size. Similarly the signal to noise concept is a function of pixel dimension.
4. What really sucks in APS-C vs. FF discussions is that all K-mount lenses are designed to fit FF DSLR light paths - the mirror of a fullframe camera still goes up and down. The image circle may be less than fullframe, but the rear lens element has to be further away than it would have to be. 5. This is troublesome for wideangle lenses as you will end up with more glass and distortion than necessary. For tele lenses there is no disadvantage.
1. Well no, K-3 has more pixels than a 6D, a Lumix DMZ1000 one inch sensor has more pixels than many old Canon Full Frames.
2. Huh?
3. How does the Lumix with a 1 inch sensor out resolve a Canon 6D?
4. The functionality to a shorter lens registration has not been established. There's a lot of evidence this is just manufacturer hype. The Pentax registration is 43mm. So you can make a fairly compact 43mm lens, like the 40XS. Longer and shorter you have to design the lens to be functional with a shorter or longer registration distance. Moving that point doesn't change anything. You still get heavier and need more corrections, the further you get from the registration point. It has been suggested , again, by the manufacturers that the short registration makes a difference. They also claim that if you should buy their camera, whether it's appropriate for you or not. Believe they have your interest at heart if you must. The only advantage I can see to a shorter registration distance is you can tell folks that with an adapter they can use their old favourtie lenses, and then try and get them to buy something of their manufacture after they make the purchase and realize what a crappy solution that is.
5, Then why does Sony and other short registration cameras have in body lens correction, just like Pentax? It's not because they can reduce the problems of distortion by changing the registration distance, they already did that.

Not trying to be too hard on you, but a lot of this doesn't make any sense. My personal guess is that the problem of the angle of light created by a short registration distance affects way a sensor absorbs light. That's why you see pictures of a Sony 70-200 mounted on an A-7 and it looks the same as any other 70-200 on any other camera.. IN fact it looks like they created a standard 40-44mm registration distance by putting a spacer in the lens, creating a 40-44mm registration distance even though a true native lens would mount right on the camera body with no spacer. They did that for a reason.

You really need to make sure there are no real world examples that contradict your hypothesis before posting this kind of thing. But keep plugging. Once you understand it, it's simple. Mind your lw/ph, and find a lens you love. Buy the camera that goes on it.

Or to make it even more simple, take lots of pictures. Try to figure out what's wrong. Take more pictures. DOn't worry about the theory. You can learn to be a great photographer without intellectual knowledge of the process. You can't become a great photographer without tons of experience shooting pictures. If believing there is some kind of benefit to short registration gets you going, go with it. As long as it keeps you shooting with confidence.

But, I don't see the Pentax registration distance as a problem, and niether does anyone else except maybe some short registration manufacturers. And they just want your money.

Last edited by normhead; 03-13-2017 at 07:14 PM.
03-13-2017, 06:15 PM   #25
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QuoteQuote:
As has been pointed out above, the easiest thing to do, is look through the view finder, take the picture you want with the camera you have, and do what you do with it. It is very unlikely that you are going to push the limits of your camera, no matter what you are shooting.
Yes. I switched from the K5 to the K3-II to give me more pixels for cropping pictures of moving wildlife. For anything else, my K5 was fine.

And my cameras are now the K3-II when I need the flexibility, my Ricoh WG-4 GPS, if it's raining hard, or my Sony RX100-V if it's not raining and I don't want to carry the K3. Any of them are fine, under appropriate conditions.
03-13-2017, 07:20 PM   #26
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QuoteOriginally posted by Keith23 Quote
Yes. I switched from the K5 to the K3-II to give me more pixels for cropping pictures of moving wildlife. For anything else, my K5 was fine.

And my cameras are now the K3-II when I need the flexibility, my Ricoh WG-4 GPS, if it's raining hard, or my Sony RX100-V if it's not raining and I don't want to carry the K3. Any of them are fine, under appropriate conditions.
Pwesonally just abandoned the former Pentax W series, now the Ricoh WGx . I got a Nikon Coolpix 130AW for $200 CDN. I loved my WG series cameras, I still have one, that won't keep the time and date anymore after being submerged under a skidoo trail/swamp for three months. But they were twice the price, and money is money, and Ricoh hasn't done much with it lately. Some reviewers are refusing to review the new one, saying it isn't any different than the last one, and because 1.5 seconds between images is ridiculous in this day and age.
03-13-2017, 10:29 PM   #27
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QuoteOriginally posted by normhead Quote
The Pentax registration is 43mm.
For what it's worth (not much), the K and M42 mounts have a 45.46mm registration distance.

The reason for the 43mm lens focal length is its near-equivalence to the film/sensor diagonal (a proxy for "normal" focal length across formats).

But yes I agree that certain focal lengths are easier to design for specific registration distances.
03-14-2017, 03:29 AM   #28
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QuoteOriginally posted by normhead Quote
Don't worry about the theory. You can learn to be a great photographer without intellectual knowledge of the process.
So there's hope for me yet then Norm.
03-14-2017, 04:57 AM   #29
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QuoteOriginally posted by Kerrowdown Quote
So there's hope for me yet then Norm.
Let's not start talking crazy....

---------- Post added 03-14-17 at 07:58 AM ----------

QuoteOriginally posted by filoxophy Quote
For what it's worth (not much), the K and M42 mounts have a 45.46mm registration distance.

The reason for the 43mm lens focal length is its near-equivalence to the film/sensor diagonal (a proxy for "normal" focal length across formats).

But yes I agree that certain focal lengths are easier to design for specific registration distances.
That's what I like about this place, there's no excuse for making the same mistake twice. Someone corrects you the first time.
03-14-2017, 07:24 AM   #30
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QuoteOriginally posted by normhead Quote
Let's not start talking crazy....
So I'm to take that, as a no then?
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