The Villages Loc: The Villages, Florida

Have a crop DSLR. Thinking of going to a Full Frame and trying to determine what the the longest focal length (on average) I am in need of....by reviewing pictures I have taken.

I shot Nikon, so I am fully aware of the "field of view" 1.5 factor. Soooo, when looking at the shooting data for a particular picture I'm provided with 2 figures, one for "Focal Length", the other for "35mm Focal length" For example the focal length shows 200MM and the 35 focal length shows 300MM (the affect of the 1.5 factor).

I'm trying to determine IF I had taken the picture with a Full Frame camera, which number should I be going by in helping me to determine (on average) which focal length on the long end I should be aiming at.

Appreciate your insight.

jerryc41 Loc: Catskill Mts of NY

If I understand you question, for a FF, the Focal Length and 35mm FL would be the same.

f8lee Loc: New Mexico

If you had used a FF camera then the 300MM (in your example) is the value to note. That is, to capture the same field of view on a FF body you would need a 300MM lens (again, in your example). So the 35 MM focal length value is the one you want to pay attention to.

The Villages Loc: The Villages, Florida

Jerry, I would agree since there is no "factor" involved with a FF. BUT for the picture taken, what is the appropriate number to go by. The zoom was set at 200mm but I'm also given the 35mm (FF) equivalent. So for the given picture now being shot on a FF, what number do I say it would be shot at? Do I need a MM of 200 or 300? Don't want to pick a focal length that won't meet my general needs.

BebuLamar

You would need the 300mm

whwiden

If you want to use a FF do everything lens, the current choice is largely made for you-a 28-300mm lens. Similarly, if you want a couple of zooms, the current 70-300mm afp is so good, you might not look at the 70-200mm f/4. Pair that with the 28-85mm.

Naldo

This ^

If you're asking how to get the same image with a full-frame camera as with your cropped-sensor (APS-C) camera: A 300mm lens on a full-frame camera will show the same image proportions as your 200mm lens shows on your cropped-sensor camera.

The Villages Loc: The Villages, Florida

Thanks for the reply, but not looking at the type of lens - just looking to determine what long end focal length I should look to based on a history of pictures.

LFingar Loc: Claverack, NY

You are incorrect in one aspect: Your 200mm is 200mm regardless of which body it is on. The focal length does not change, only the field of view. If you were to superimpose the APS-C shot on top of the full frame shot you would find that the magnification is identical. I find that APS-C is best for shots where your subject matter is a relatively small portion of the photo. Wildlife, BIF, some sports, etc. Otherwise, I prefer full frame. For full frame I find that 3 lenses cover the majority of my shooting: 16-35, 24-105, and 100-400. Beyond 400mm the lenses tend to be quite pricey, quite heavy, or both. If I need a bit of extra reach a 1.4x extender does the job. For a FF one of the handiest all-around lenses is something in the 24-105 range, IMO. Because full frame is normally superior to APS-C in low light/high ISO situations you may well find that the more expensive fast lenses are not as important, depending on your shooting.
If you are going full frame I suggest you get one all-around lens, such as a 24-105 (popular with Canon. Not familiar with Nikon), and see where your shooting takes you from there.

rehess Loc: South Bend, Indiana, USA

This statement if factually true, but it is a confusing and misleading statement. No one cares what the physical image on the sensor looks like - what they care about is what the printed image or displayed image looks like, and the APS-C image is magnified more than the FF image is to reach the same printed or displayed size.

To answer the original question, a "FF" camera will act exactly as a "35mm" camera would. If you're told that this was a 200mm lens, which is "equivalent to a 300mm lens on a 35mm camera", then you would want a 300mm lens on a FF camera to get the same image. If you're told that this was a 50mm lens, which is "equivalent to a 75mm lens or a 35mm camera", then you would want a 75mm lens on a FF camera to get the same image.

The Villages Loc: The Villages, Florida

Appreciate your thoughts, but your analysis goes further then I think I need. Sorry if I am not explaining correctly.

Going back to my original post, IF I took 100 pictures whose data read 200mm focal length and 300mm 35mm focal length (this is from a crop camera), but I know that in the future I'm going to be shooting with a FF, should whatever lens I purchase have a long end of 200mm or 300mm.

Just trying to use past shooting history to determine long end mms.

BebuLamar

If you found that you are likely to need 200mm on your APS-C camera then you would need 300mm when you switch to FF. It's simple as that.

Joe Blow

Very correct. 200mm is 200mm, whether I end up cropping it in post editing or in the camera. That crop is what makes the difference in the end. They are the same before the end.

One problem that is contributing to the question is in the thinking. DSLRs grew out of 35mm and the language is standardized to that 35mm format. APS-C is a variation of 35mm but the question is phrased in APS-C instead of talking in 35mm. Trying not to fault the OP, I feel we should learn what our SLRs are about. It isn't just the "exposure triangle", but what the focal length means, the results of aperture to focus, sensor sensitivity vs noise, etc. In fairness though, we would never learn this stuff unless we ask.

TriX Loc: Raleigh, NC

If your question is that you are moving from crop to FF and want the same FOV (field of view), then you will need a lens 1.5x (Nikon) or 1.6x (Canon) the crop FL for an equivalent FOV on the FF. IE: you will need 320mm on a Canon FF (or 300mm on a Nikon) to produce the same FOV as the 200mm on the crop body. Is that what you’re trying to decide?

Largobob

Your question has been answered very nicely by several members. Be cautious when looking at metadata from previous pics....did you also crop the image in post? If you did, then just looking at the focal length of the lens will mislead your decision.