[aleonx3]

I'm by no means an expert on optical science, but I'm pretty sure you're misinformed. So what you're saying is that if you took a 5D and a 50, and made an exposure at 1/125th, f/5.6, iso200, then put the lens on a 40D, and made the exact same exposure, that the 40D photo would be 1 stop less exposed?

Yes, the same amount of light enters the lens, and yes part of that light doesn't hit the sensor, whereas it would have on a FF sensor. But, the light that isn't hitting the sensor is the same light that isn't part of the image anyways. The smaller sensor is cropping out the center of the image, and it's that cropped out light, which isn't part of the recorded image anyways, that isn't hitting the sensor. The amount of light at the pixel level is the same on either chip. The FF sensor isn't recording more light per pixel sight, it's recording more light in general because it's recording more image. Of course I could be wrong.

Anyone else want to chime in on this?

I believe you are correct; I do not understand cwood's logic..

[Digitalis]

The same amount of light will come through the lens but because of the smaller sensor the same amount of light does not hit the sensor. Therefore F2.8 on FF is equivalent to exposing at F4 on APS-C.

completely and utterly inaccurate, sensor size has no effect on the light transmission of a lens. providing the lens remains the same distance from the recording medium, the amount of light hitting said recording medium will be identical. Irrespective of the scale of the image recording area, taking the limitations of the imaging circle of the lens into account.

the only situation where that statement is accurate is in regards to DOF.A 50mm lens on a 1.5x APS-C format sensor has 1.5x more DoF than the same 50mm lens will have on 24X36mm sensor* at the same aperture. So using a f/1.2 lens on a 1.5x reduced format sensor provides the depth of field of a f/1.8 lens but all the optical compromises of using a f/1.2 lens at it's widest aperture.

*providing the camera to subject distance ratio is identical.

[johnmflores]

Oh noes, another post veering off into APS-C vs. FF!!!!!

I must try to save it...

Let's flip the question upside down and see if it makes sense - can you name a Nikon or Canon pro that would not be able to be a pro photographer if they shot with Pentax instead?

[FullertonImages]

Oh noes, another post veering off into APS-C vs. FF!!!!!

I must try to save it...

Let's flip the question upside down and see if it makes sense - can you name a Nikon or Canon pro that would not be able to be a pro photographer if they shot with Pentax instead?

Excellent work, John!

Great question too. Or even, are there any CaNikon pros who wouldn't be able to get the job done with CaNikon's top APS-C offerings?

[magkelly]

Absolutely it can be done as hundreds of professional photographers over the years can tell you. There's a reason a good number of photography course teachers still nod approvingly when some student shows up with a K1000 in hand. It's because they know it's a stable, workhorse of a camera, perfect for learning with. yeah, they're happy to see others too, but I've actually known several photography teachers who go out of their way to purchase K1000's for their students as they can. Why? Because they've used either a K1000 or some other camera for years professionally and they know that they can reply upon them to do the job.

For the record I know three different photographers all in different fields who do shoot with Pentax regularly as well as Nikon and Canon when the situation demands it. They use the best camera and lenses for the job, the one they prefer and they don't worry about which lettering is on them.

One of those guys has been shooting with a film Pentax since he was a soldier in Vietnam and he was given his first one. Another has worked in fashion and advertising for more than 40 years and his digital camera of choice is a Pentax DSLR, of late, the K-7. For his own fun he also shoots with a grand assortment of vintage Pentax (and other brands) cameras, everything from an old SPII to a K1000. The 3rd guy, well, he's just not much into the "digital revolution" so far. He's still shoots several Pentax film cameras every day on the job even though it means he has to go and develop film and scan his negatives to use them.

I have nothing against other brands of cameras. I like several, but having used it for a bit now I wouldn't trade my *ist for a brand new Nikon, seriously. I just like this camera and if this is what using all Pentax DSLR's is like? Well, a year or two down the road when I am doing my thing professionally? I will be shooting a weather-proof Pentax wonder camera like the K5/K7. Why? Because every Pentax camera I've ever picked up and shot has made a huge fan out of me.

(Well, except for the P3 series. I did pick up one of those once. The design made me shudder though and put it right back down. It was so ugly I couldn't bring myself to further the acquaintance even though it's supposed to be a good camera internally.)

I do agree that even the most advanced Pentax cameras don't do everything every pro might want, but I think for the vast majority of people not into shooting for the NFL, for instance there is a heck of a lot of capacity there to utilize. Honestly, the K5/K7 will probably be more than enough camera for my needs, but that's me, and I don't happen to need to be able to shoot the Superbowl. If you do? Grab a Nikon and be happy. I'll stick with my Pentax though and I won't give a D- if the rest of the photography work thinks I'm silly for choosing the best camera for ME.

That goes for the color thing too. If some people want to take me less seriously because I am shooting a brightly colored camera? Fine, so be it. They'll soon shut up soon enough when they see what I can do with it, grin. Life is too short to be like everyone else and besides I'm just not much of a herd animal kind of person.

[cwood]

Oh noes, another post veering off into APS-C vs. FF!!!!!

I must try to save it...

Let's flip the question upside down and see if it makes sense - can you name a Nikon or Canon pro that would not be able to be a pro photographer if they shot with Pentax instead?

You are jumping to conclusions based on spending too much time on Pentax Forums... this was not a FF vs APS-C debate. They are simply different and I was pointing out the difference. You can take those same shots with an APS-C but sometimes the shots come out better with FF. I don't limit myself to APS-C cameras and I don't limit myself to one brand... I shoot with whatever I think will produce the best results for me. I would add a 645D if I could only afford it - but I can't so I guess I should I really be saying "I shoot whatever I think will produce the best results... that I can afford to shoot with".

[Ash]

The best results for *most* applications can be had with an APS-C camera just as well as a FF camera. Those who disagree will be mainly those who are depth of field extremists in their line of work - in which case FF is a clear advantage. But then why stop there when you can get a 645D...

[cwood]

The best results for *most* applications can be had with an APS-C camera just as well as a FF camera. Those who disagree will be mainly those who are depth of field extremists in their line of work - in which case FF is a clear advantage. But then why stop there when you can get a 645D...

5DmkII = $2000
645D = $10,000


also - you don't have to be an "extremist" to appreciate DOF

[johnmflores]

You are jumping to conclusions based on spending too much time on Pentax Forums...

Hey, I resemble that!

this was not a FF vs APS-C debate. They are simply different and I was pointing out the difference. You can take those same shots with an APS-C but sometimes the shots come out better with FF. I don't limit myself to APS-C cameras and I don't limit myself to one brand... I shoot with whatever I think will produce the best results for me. I would add a 645D if I could only afford it - but I can't so I guess I should I really be saying "I shoot whatever I think will produce the best results... that I can afford to shoot with".

This didn't start out as a FF vs APS-C debate, but judging from the last 10 posts it sure sounds like it is veering in that direction.

I started with film and just recently ran a couple of rolls through my trusty MX/50mm F1.7 and an Olympus XA. I know full well the difference between the two. It's there, but I challenge anyone to take a look at a collection of random photos and be able to identify which ones came from FF and which ones came from APS-C. For example:

List of winners 2010 - World Press Photo

BBC - Earth News - European Wildlife Photographer of the Year 2010

Can anyone here point to any particular photo and say that it is FF?

And to bring it back to the OP, can anyone look at any of the above photos and say, "That's clearly a Nikon, that's clearly a Canon, etc..."??? If you can't, than it's pretty clear to me that the eye looking through the viewfinder is much much more important than the brand on the pentaprism...

[eddie1960]

Hey, I resemble that!


List of winners 2010 - World Press Photo

BBC - Earth News - European Wildlife Photographer of the Year 2010

Can anyone here point to any particular photo and say that it is FF?

And to bring it back to the OP, can anyone look at any of the above photos and say, "That's clearly a Nikon, that's clearly a Canon, etc..."??? If you can't, than it's pretty clear to me that the eye looking through the viewfinder is much much more important than the brand on the pentaprism...

Excellent argument
and does anyone agree with the first place choices

I have Pro friends who shoot pretty much anything you care to name (including an Israeli chick who shoots fashion mostly with an assortment of Holgas)
As for the DOF argument if you are shooting and being properly compensated you will find a way to get the 645D for location work (excluding fast action sports then you truly will end up canikon in all likelyhood for the lenses available) or if you are studio probably a tethered phase one system or even a leica s2 if they ever manage to produce more than a couple of lenses a month.
I can also see a 645D with tethering showing up at some point.

Don't worry about your purchase go learn your craft and how to market yourself and by the time you need something consistently that you aren't able to get with your pentax gear you will be able to afford to add that second system (in the interim most good rentals also offer bodies for rent for those one offs where you need a FF canikon or a medium format digital)

[Ash]

5DmkII = $2000
645D = $10,000


also - you don't have to be an "extremist" to appreciate DOF

5D MkII = 21Mp FF sensor
645D = 40Mp MF sensor


You want to compare more fairly, then see prices of Leaf, Mamiya and Hasselblad dMF offerings...

Take your pick.
And appreciate extreme DoF all you like.

[cwood]

Ash - you're the one who said it... not me. I was just answering your question - perhaps your resources are less limited than my own? I am well aware of the value in the Pentax 645 compared to other equivalents

But then why stop there when you can get a 645D...

5DmkII = $2000
645D = $10,000

5D MkII = 21Mp FF sensor
645D = 40Mp MF sensor


You want to compare more fairly, then see prices of Leaf, Mamiya and Hasselblad dMF offerings...

This didn't start out as a FF vs APS-C debate, but judging from the last 10 posts it sure sounds like it is veering in that direction.

........

I know full well the difference between the two. It's there...

............

Can anyone here point to any particular photo and say that it is FF?
.

Sounds like you're doing a fine job debating on your own John - no need for anyone else to get involved

But seriously - I never said or implied anything more than you have said here. So who are you trying to debate?

[johnmflores]

Sounds like you're doing a fine job debating on your own John - no need for anyone else to get involved

But seriously - I never said or implied anything more than you have said here. So who are you trying to debate?

LOL. The point is that when you know that you are shooting FF you can look at the output and say, "ahhhh...." and it gives you the warm fuzzy about FF. Or it makes you nostalgic for the days of film or it helps justify the bulk and cost of a FF dSLR.

But that warm fuzzy goes away pretty quickly when faced with a blind test.

We spend a bunch of time here discussing brands and sensor sizes and whatnot, showing examples of superiority/inferiority and placing ourselves on the sides of arguments that support and reinforce our own decisions and biases.

At the end of the day though, few if any of us would be able to distinguish between brands and sensor sizes by just looking at the final product.

I get caught up in it as much as the next guy. It's just funny.

[Urkeldaedalus]

5DmkII = $2000
645D = $10,000


also - you don't have to be an "extremist" to appreciate DOF

Where are you getting that $2000 number from? If you're going by new amounts shouldn't it be:

645D = $10,000
5dMkII = $2500

Other than that, point taken.

[Ratmagiclady]

I'm by no means an expert on optical science, but I'm pretty sure you're misinformed. So what you're saying is that if you took a 5D and a 50, and made an exposure at 1/125th, f/5.6, iso200, then put the lens on a 40D, and made the exact same exposure, that the 40D photo would be 1 stop less exposed?

Yes, the same amount of light enters the lens, and yes part of that light doesn't hit the sensor, whereas it would have on a FF sensor. But, the light that isn't hitting the sensor is the same light that isn't part of the image anyways. The smaller sensor is cropping out the center of the image, and it's that cropped out light, which isn't part of the recorded image anyways, that isn't hitting the sensor. The amount of light at the pixel level is the same on either chip. The FF sensor isn't recording more light per pixel sight, it's recording more light in general because it's recording more image. Of course I could be wrong.

Anyone else want to chime in on this?

The importance of the total amount of light hitting the sensor isn't the same for many purposes, is the thing. It matters if you compare formats, as regards ultimate or particular (or potential) image quality, but a lot of the things a faster lens are helpful for have to do with the 'intensity' of light per unit area and other factors that don't change when you use a crop format.

For instance, a medium format camera may have better IQ, (Which you may not even notice till you make a real big enlargement: but, there are also subjectives involved, especially in color work) ..but that doesn't make it any easier to achieve critical focus, etc. F number is a ratio, of itself. That ratio interacts with both the 'medium,' (your film or sensor) and a great number of other factors. Many of which aren't even about the image itself, but about getting it. It's part of why 135 has been such a convenient and enduring format. Even though they made it out of respooling movie film, turning it on its side, and making a plausibly-horizontal aspect ratio. Somewhere back when Charlie Chaplain was big.