[BillyCooper]

Hello all, and always, thanks to all for this wealth of info and generous sharing....

After my first deep dive into silver halide crystals, and all the accessories to, I purchased a first gen Canon digital 16 years ago, and proceeded to get real dumb, photogenically lazy and i even gained weight; fast forward to 2018; I purchase a K1mii this past summer, then I come here and proceed to observe the "effective" focal length of an APS-C, when using a long a telephoto, is greater than the same lens on an FF rig (all logic aside).

So I have 2.5 questions....

1)a So is my thinking correct that a 300mm lens has more reach on an APS-C than a FF, like my K1,

or 1)b is this only true in cases where pixel counts are the same on both rigs, but the pixel density is higher on the smaller sensor?

I ask because it all boils down to man's greatest insecurity; length envy. So here comes the dumb question (born out of simply not knowing)

So if 1)a is true, 2) Will my effective focal length on my "hypothetical" 300mm lens increase on my K1 simply by switching to APS-C mode? (my guts are screaming at me for even asking, because none of it makes sense to my left hemisphere, while at the same time, it's also yelling "not unless the pixel density changes too", which is impossible, "right"?. (i assume pixel density is the unicorn, whatever voodoo it is in the black box, I just need to know before i go purchase a lens that will under-serve me based on flawed critical thinking.

And to answer this question before it gets asked, I will be using the camera mostly for slower action (for instance, two cars staging at a dragstrip, before they launch, and on the other side of the coin, nature/ls photos for source material for my watercoloring. (I own a 15-30 so im covered in that realm of composition). And to elaborate further, I may take pictures of the cars at the starting line as much as 400+ feet away, but possibly as close as 150-200ft.) I'm considering the 150-450, but there is a sweetheart 300mm F* I've also got my eye on and i may also put a teleconverter behind that. What really has me intrigued on the prime, is the absolute rave love on this forum, for it, and the fact that it's 5-6 benji's cheaper (plus it's hand-holdabilty) THANK YOU ALL IN ADVANCE

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Last edited by BillyCooper; 11-06-2018 at 10:53 PM.

[aoeu]

1 yes
2 no
You get the same result as cropping except that it only tries to focus on the middle.

[normhead]

The extra reach of APS_c comes from having a denser pixel density.
So you get more subject resolution because for the size of the APS-c sensor, on the K-1 you get 15 MP, about the same as a K-5. With the K-3 you get 24 MP in the same area.

If you have a K-5 you may as well use the K-1 in crop mode.
In lw/ph, a K-3 will produce about 2700 lw/ph, a K-5 about 2100-2200 lw/ph. In areas where you can't get closer the DA*200 is better. Especially if you put the 1.4 TC on it. If you can walk in with the K-1 and fill the frame, well then it's about an extra 800 lw/ph for the K-1.

But for straight field of view here we have a DA*200 2.8 and a Tamron 300 2.8. You may not get the same resolution from the K-3 and DA*200 but you's save 4.5 pounds.


Essentially you get the same field of view, more resolution from the K-1, but you probably won't notice the difference very often.

If you have two 24 MP images, from both FF and APS-c, you get visually the same image, providing you aren't in low light (above 400 ISO). The difference is about 100 lw/ph, and you can't see it.

[PJ1]

The FF sensor is 36 mm x 24 mm
The APS-C sensor is 23.5 x 15.6mm (Canon APS-C is slightly smaller).


If you put a 300mm lens on an APS-C sensor camera, you only use roughly 2/3 of the width (or height) of the image that would be projected onto a FF sensor. In other words, you get a smaller angle of view. It is still a 300mm lens, but (because the FF sensor is 1.5 times wider than the APS-C sensor) the angle of view is what you would get from a 450mm lens on FF. It is a simple mathematical relationship. Put that 300mm lens on a Pentax Q with a 1/2.3" sensor which is 6.17mm wide and the angle of view is what you would get using a 1750mm lens on FF. But it is still a 300mm lens. IT is just the angle of view that changes because that is determined by the size of the sensor.


Pixel density has an impact on the quality of the image you can expect. As has been pointed out, if an image taken on a 36MP FF sensor is cropped to APS-C sensor dimensions, you reduce the angle of view and you are left with a an image of about 15MP - comparable with the 16MP image of the K-5 - which should be OK for most purposes.

[UncleVanya]

Another Difference of apsc is frame rate and buffer size relative to continuous shooting modes. The k-3 fires faster and with more shots before the buffer is filled.

Reach is confusing but i think the posts above already sorted that.

[Sandy Hancock]

Norm has summarised it perfectly.

For what it's worth, I'm taking my DFA150-450 on a very big trip shortly (along with the DFA15-30, DFA28-105, DA10-17 and DA*55). I'll be taking both crop and full frame bodies to exploit their reach and resolution respectively.

I also have a 300mm prime and a 1.4x teleconverter, which together give about the same reach, but for what I need on this trip the convenience of a zoom won out. Which option you go for should depend on your needs rather than anything we say though

[beholder3]

1)a So is my thinking correct that a 300mm lens has more reach on an ASP-C than a FF, like my K1,

You just need to memorize the core fact that it all is about image magnifications, much less about sensor sizes or pixel count (primarily).
Why? Because everybody creates photos of the same output size, regardless of technical aspects of a camera = you watch both APSC and "FF" images on the same screens.

But since the image capturing sensors have different sizes it means you have to magnify the smaller sensor image more (APSC diagonal x1.5 more than a FF).

Since this is about magnification you just need to think a smaller sensor image as the result of a "magnifying glass" held over the central part ("crop") of the larger sensor image. Once you understand this, all other consequences are quite self explanatory:
- you see the center larger, like through a telescope, providing you "more reach" even though it is just something more magnified after capture.
- if you'd create output with the same magnification level, say watch an APSC image on a x1.5 smaller screen, it is absolutely the same as the FF image. Same reach, same noise, same dynamic range, same DoF etc.

- all glass weaknesses get magnified as well
- all other bad image aspects like noise pixels get magnified as well

- you see through the center part of the lens, so the edges with bad vignetting are avoided
- for same "pixel count" you need an FF sensor with 1.5x1.5x the pixelcount of the APSC sensor.

[photoptimist]

It depends on what you mean by reach:

If "reach" means the distant object fills as much of the frame as possible in the viewfinder, backpanel display, or web-posted image, then only the frame size matters. By this definition, APS-C and K-1 crop mode have more reach than the K-1 or any other FF camera.

But if "reach" means being able to print the distant object as large as possible, then pixel density and sometimes total pixel count matter. An enlargement of a distant car printed at say 150 dpi will show that the K-3 has more reach than either the K-5 or K-1 which all have more reach than the K-10D. Sometimes total pixel count size also matters if the object is large enough to fill the frame of an FF camera with your available lenses so that you can't use the same focal length for both APS-C and FF. A K-1 with a 300 mm lens has more enlargement printing "reach" than a K-3 with a 200 mm lens.

[normhead]

It depends on what you mean by reach:

If "reach" means the distant object fills as much of the frame as possible in the viewfinder, backpanel display, or web-posted image, then only the frame size matters. By this definition, APS-C and K-1 crop mode have more reach than the K-1 or any other FF camera.

But if "reach" means being able to print the distant object as large as possible, then pixel density and sometimes total pixel count matter. An enlargement of a distant car printed at say 150 dpi will show that the K-3 has more reach than either the K-5 or K-1 which all have more reach than the K-10D. Sometimes total pixel count size also matters if the object is large enough to fill the frame of an FF camera with your available lenses so that you can't use the same focal length for both APS-C and FF. A K-1 with a 300 mm lens has more enlargement printing "reach" than a K-3 with a 200 mm lens.

My only question is "how many pixels across is my subject?'
The K-3 will give you more subject pixels, as long as it isn't too much and actually cuts part of it off, or doesn't match the amount you need for cropping.

[reh321]

It depends on what you mean by reach:

If "reach" means the distant object fills as much of the frame as possible in the viewfinder, backpanel display, or web-posted image, then only the frame size matters. By this definition, APS-C and K-1 crop mode have more reach than the K-1 or any other FF camera.

This is an over-simplification ..... "APS-C" depends on which camera you are talking about. My {16mp) K-30 will put just about the same number of pixels on a particular subject using a particular lens from a particular spot as a K-1 would; a {24mp} KP or {24mp} K-3ii would put more pixels on that subject using that lens from that spot - so I could crop the KP or K-3ii photo in gimp to fill more of the frame and still have 16mp.

Using crop mode on the K-1 does not affect the "pixels on subject". If I were to use my AdaptAll 60-300mm lens {by definition, lenses built for 35mm film are "FF" lenses} at 300mm to take a photo, a K-1 would give me exactly the same photo - exactly the same number of pixels-on-subject - regardless of whether the K-1 was manually set to be in crop mode or I cropped the photo afterwards in gimp.

[photoptimist]

My only question is "how many pixels across is my subject?'
The K-3 will give you more subject pixels, as long as it isn't too much and actually cuts part of it off, or doesn't match the amount you need for cropping.

Yes, that's the "how big can I print" definition of reach which is the only one that should matter.

In contrast, if your definition of reach is based on envy of the review image on the backpanel of the next guy's APS-C camera, then pixel density does not matter. But in this case, putting the K-1 in crop mode saves the day and your ego.

[normhead]

Yes, that's the "how big can I print" definition of reach which is the only one that should matter.

In contrast, if your definition of reach is based on envy of the review image on the backpanel of the next guy's APS-C camera, then pixel density does not matter. But in this case, putting the K-1 in crop mode saves the day and your ego.

Ya, that's important.

[BillyCooper]

Well, I'm sure you all surmised my question was grounded in my desire to purchase the best value/"reach" (as defined in it's numerous flavors), for my particular camera. What I was hoping to hear, was that I could comparably make do with with a shorter lens, at the expense dimensions, without having to sink nearly 2k into a 150-450.

And I'm sure that many of you will understand what I'm about to share; If I wasn't so happily married, perhaps decisions like this would not have to be so agonizingly rationalized. I'd just do whatever my impulses requested of me.

So I weighed much of what has been said here, and began to see that if I went on a journey of discovery, I'd probably, in the end, end up spending way more money than I was trying to avoiding in the first place. (those older lenses truly are seductive, and I would "love" to try them all.

And then something happened that I did not expect at all. The guy who is selling the F* Star 300 F4.5 Pro Series on ebay, that drove me to my question, upon making an inquiry about his lens condition (looks primo), he came out and confessed I'd probably be happier with a newer lens. Wow. I mean, I was ready to "buy it now".

And so it was, with the rationalization of sparing my poor wife future angst (i can be magnanimous, at times), and this gentleman's gentleman, who probably understood better than I, what was best for me, i decided to just go ahead and spring for the 150-450.

Now I'll be able to find out for myself, with my single camera, in crop and full frame, everything I need to know, in my limited sense.

And boy, do you guys know how to cover a topic. I'm going to have to review this thread a couple of more times, slowly, to take it all in.

And just to throw a little more miracle grow on the topic, yes, I fully plan on shooting, and printing, in large format, because in my profession (residential design studio owner), it just so happens I have to own a 36" large format printer too. So there's that, and I'm planning on spraying a few billion droplets

THANK YOU ALL SO MUCH!

My very best regards,

Bill

[clackers]

And then something happened that I did not expect at all. The guy who is selling the F* Star 300 F4.5 Pro Series on ebay, that drove me to my question, upon making an inquiry about his lens condition (looks primo), he came out and confessed I'd probably be happier with a newer lens. Wow. I mean, I was ready to "buy it now".

You got to thank him for his eventual honesty about the condition of his copy of the lens, but you should snatch another one like it if it becomes available.


The FA* 300 f4.5 is my lens of choice for birds, coupled with my K-S2 rather than my K-1 and often boosted with the 1.4 HD TC for extra reach.

Longer I've figured just gets more expensive for marginal gains. The best strategies of all involve taking the pics from as close as possible. That's at one end of the sports field, forget the other, and waiting for birds to come to where you've put the camera instead of wandering around looking for them.