Ugly Hedgehog® - Photography Forum
Zoom reach on crop sensors
If you want to reply, then register here. Registration is free and your account is created instantly, so you can post right away.
Page: <<prev 1 2 3 4 5 6 next>>
Jan 12, 2019 08:16:32   #
Fotomacher
 
DebAnn wrote:
I understand that zoom lenses "reach" further on crop sensor cameras. Does a zoom lens specifically designed for a crop sensor camera have that effect? For instance, does a 55-250 mm zoom made for a crop have an effective reach of around 400 mm? Or does that only apply to lenses that work on both full frame and crop?


Why does think continue to be soooo complicated. Digitally cameras have been around for close to 20 years! The specifications on the lens are the physical characteristics of the lens and have NOTHING to do with the body its mounted on. The sensor is defined in terms of its relationshipship to the size of a 35mm film frame. So a sensor that is 2/3 of the size of a 35mm film frame is a sensor that has been “cropped”. As a result, the field of view is only 2/3 of what you’d see on a “full frame” digital camera.the reciprocal of 2/3 is 3/2 or 1.5. Park that for a moment.

If you mount a 250mm lens on a camera with a sensor size that is 2/3 the size of a 35mm frame, the field of view relative to a full frame will be 1.5 times less and give you the effect of a digital zoom of 250x1.5 or 375mm. The benefit of using a crop sensor body is that you will be using ALL of the mega pixels on the sensor for your image, versus discarding pixels by cropping the image in post-production.

OK?

| Reply
Jan 12, 2019 08:16:40   #
Longshadow (a regular here)
 
DAN Phillips wrote:
So, if I put a Sigma 150-600 on a Nikon D5000, how will that compare to when I put it on a Nikon D750?
I appreciate your help!

Whatever the crop factors are for the respective camera. (I've no idea what they may be for each camera.)

| Reply
Jan 12, 2019 09:11:15   #
rond-photography
 
DebAnn wrote:
I understand that zoom lenses "reach" further on crop sensor cameras. Does a zoom lens specifically designed for a crop sensor camera have that effect? For instance, does a 55-250 mm zoom made for a crop have an effective reach of around 400 mm? Or does that only apply to lenses that work on both full frame and crop?


100MM is 100MM no matter what you put it on. On a 35MM (full frame) it is a slight telephoto. On a medium format (6CM X 9CM) it is a "normal" lens, and on an 8X10 camera it is a wide angle.
I chose to use film sizes of traditional cameras here to emphasize that it has nothing to do with crop sensor vs full frame. It is just physics.
One difference between crop sensor lenses built just for those cameras vs the same focal length for a FF is that you can design the crop sensor lens more cheaply, since you don't need to cover such a large sensor. For example, that 100MM lens I referenced if used on a 35MM film would just cast a spot on the center of the 8X10 sheet. The 100mm lens for the 8X10 would be much larger in diameter, and much more precise in how it is ground, to cast light evenly over the entire 8X10 sheet.

| Reply
Jan 12, 2019 09:30:48   #
Longshadow (a regular here)
 
DAN Phillips wrote:
So, if I put a Sigma 150-600 on a Nikon D5000, how will that compare to when I put it on a Nikon D750?
I appreciate your help!


Turns out, both bodies are FX, the image will be the same.

| Reply
Jan 12, 2019 09:48:55   #
Linary
 
Longshadow wrote:
Turns out, both bodies are FX, the image will be the same.


D500 is not a full frame camera.

| Reply
Jan 12, 2019 09:51:44   #
jerryc41 (a regular here)
 
Talk about a can of worms! : )

It's all just terminology. Look through the viewfinder, and what you see is what you see.

| Reply
Jan 12, 2019 09:57:16   #
Longshadow (a regular here)
 
Linary wrote:
D500 is not a full frame camera.


Right!. I did a search at one site and the 750 came up instead of the 500. I didn't check that it resulted in what I was searching.
So I go back to my original answer, whatever the crop factor difference is between the two.

| Reply
Jan 12, 2019 11:29:22   #
frankraney (a regular here)
 
DebAnn wrote:
I understand that zoom lenses "reach" further on crop sensor cameras. Does a zoom lens specifically designed for a crop sensor camera have that effect? For instance, does a 55-250 mm zoom made for a crop have an effective reach of around 400 mm? Or does that only apply to lenses that work on both full frame and crop?


All sensors are cropped sensors so to speak because lenses are round and produce around picture, and your sensor is square. This is not what we're talking about though, when we talk about cropped sensors.

What we're talking about when we talk about cropped sensors, is a comparison to what a cropped sensor gets as compared to a full frame sensor. If we have a cropped sensor with a crop factor of 1.5, with a 50mm lens, then it will get approximately the same photo as a 75mm on a full frame.

Other than understanding the comparison it's really overrated (imho) I wouldn't worry about it, I would just shoot my pictures have fun and enjoy it, because what you see is what you get with a mirrored camera.

Here is a link that will completely explain it with examples if you really want to understand it I think it's good.

https://www.digitalphotomentor.com/crop-sensor-camera-real-meaning/

| Reply
Jan 12, 2019 11:33:07   #
Photocraig
 
DebAnn wrote:
I knew this would geet more technical than I need. So I'm simplifying the question. If I use my Canon 70D camera (crop) with a 70-300mm lens and shoot a photo of a lion that's in the distance, will I get a closer-looking shot than if I used the same lens on my Canon 6D II? Yes or no?


DebAnn, you used the MAGIC word (sorry Groucho's outa $50 bills). The word is "looking!" All lenses are measured and marketed with their "native" focal lengths. What image (a circle) they project is measured according to a fixed formula. While this seems to create some confusion, keeping them standard, and leaving it up to the user to figure out what the images will "look Like" on their camera format eliminates greater confusion.

The good news is with yout 70D what you see in your viewfinder or screen is what you will get in your recorded image.
C

| Reply
Jan 12, 2019 11:56:19   #
frankraney (a regular here)
 
DebAnn wrote:
I understand that zoom lenses "reach" further on crop sensor cameras. Does a zoom lens specifically designed for a crop sensor camera have that effect? For instance, does a 55-250 mm zoom made for a crop have an effective reach of around 400 mm? Or does that only apply to lenses that work on both full frame and crop?


Debann, yes, the 250mm on your crop will appear as a 400mm on a ff. If you take the same shot with a crop and a ff, both at say 100mm, the cropped will appear as zoomed in or closer.

| Reply
Jan 12, 2019 12:31:29   #
amfoto1 (a regular here)
 
DebAnn wrote:
I understand that zoom lenses "reach" further on crop sensor cameras. Does a zoom lens specifically designed for a crop sensor camera have that effect? For instance, does a 55-250 mm zoom made for a crop have an effective reach of around 400 mm? Or does that only apply to lenses that work on both full frame and crop?


Any 250mm lens on a crop sensor camera will give exactly the same angle of view regardless... doesn't matter if it's a "crop only" lens or if it's a "full frame capable" lens.

If you have only ever used a crop sensor camera, forget about "effective reach". It won't mean anything to you. The only time you have to concern yourself about the "effective reach" is when going back and forth between formats. For example, if you used to shoot with a typical 35mm film camera & lenses and are now trying to buy lenses for an APS-C crop sensor camera that will perform similarly on it, you'll need to do some math to help with lens selection. Or, if you have been using a crop sensor camera for a while and decide to switch to full frame or to add a full frame camera to your kit that will be used alongside your crop camera, you'll need to do some math to know how any compatible lenses you currently have will "behave" on the larger format and what lenses you might need to add, depending upon your purposes with the camera.

Depending upon what format it's used upon, any given focal length will "behave" differently. Just for example, on an APS-C camera a 30mm lens acts as a "standard" lens... not wide, nor telephoto. But on full frame it would be a wide angle lens. For that matter, on a medium format camera with an even larger image area, a 30mm lens would act as an "ultra wide". Or on a digital camera with a tiny 1/2.3" sensor, much smaller than APS-C, that same 30mm would behave as a telephoto!

All you really need to know, though, is how focal lengths "behave" on the camera format you use. You only need to worry about "conversion factors" when you use multiple formats of cameras or are switching between them.

It sounds as if you are using a Canon 70D, which uses an APS-C sensor (1.6X "lens factor"). On that camera, you'll find the following:

10-22mm is an ultrawide to wide angle zoom
17-55mm or 18-55mm or 15-85mm or 18-135mm is a "standard" or "walk-around" zoom that covers wide angle to standard to short telephoto or moderate telephoto.
55-250mm or 70-200mm or 70-300mm or 100-400mm are more powerful short or moderate telephoto to strong or super telephoto zooms.

Another difference is that in many cases a crop sensor camera such as yours can make full use of both crop sensor and full frame design lenses. In contrast, a full frame camera basically requires full frame capable lenses. (Note: Some cameras allow crop design lenses to be used, but in most cases the image will be heavily cropped so it's sort of a waste of the full frame camera to use it that way.)

And, finally, lenses designed for crop cameras are typically smaller, lighter and less expensive than those designed for full frame. For example, I often use a $1300, 3 lb. 300mm f/4 lens hand held on a crop sensor camera to shoot sporting events. To have the same "reach" and speed (lens aperture) with a full frame camera I'd need to fit it with a $9000, 8 lb. 500mm f/4 lens that pretty much requires a sturdy tripod.

| Reply
Jan 12, 2019 13:24:15   #
Siemienczuk
 
One more question. I think I know the answer, but interested to hear other thoughts. My ability to handhold and obtain a reasonably sharp image is related to focal length and shutter speed. The longer the focal length, handheld, the quicker the shutter speed needed. For this question, ignore technique (stance, bracing) and use of image stabilization. A well known guideline is the reciprocal of the focal length. So if I’m using a FF sensor with lens 300 mm, a good benchmark is a shutter speed of 1/300 or faster. If I use a 300 mm lens with a DX sensor, does that reference change to 1/450 or is it still 1/300?

| Reply
Jan 12, 2019 13:56:31   #
PHRubin (a regular here)
 
DebAnn wrote:
I understand that zoom lenses "reach" further on crop sensor cameras. Does a zoom lens specifically designed for a crop sensor camera have that effect? For instance, does a 55-250 mm zoom made for a crop have an effective reach of around 400 mm? Or does that only apply to lenses that work on both full frame and crop?


ANY LENS will produce an image on a crop sensor camera that appears to have more "reach" than when on a full frame camera. This is not changing the focal length, just cropping the result to get a narrower field of view. As previously indicated, this is due to the sensor using a smaller portion of the projected image than a full frame sensor so the subject appears bigger.

Of course a crop sensor lens will not fill the sensor of a full frame camera at all, if any, focal lengths.

| Reply
Jan 12, 2019 14:07:10   #
Longshadow (a regular here)
 
PHRubin wrote:
ANY LENS will produce an image on a crop sensor camera that appears to have more "reach" than when on a full frame camera. This is not changing the focal length, just cropping the result to get a narrower field of view. As previously indicated, this is due to the sensor using a smaller portion of the projected image than a full frame sensor so the subject appears bigger.

Of course a crop sensor lens will not fill the sensor of a full frame camera at all, if any, focal lengths.



| Reply
Jan 12, 2019 14:21:39   #
ronpier
 
Siemienczuk wrote:
One more question. I think I know the answer, but interested to hear other thoughts. My ability to handhold and obtain a reasonably sharp image is related to focal length and shutter speed. The longer the focal length, handheld, the quicker the shutter speed needed. For this question, ignore technique (stance, bracing) and use of image stabilization. A well known guideline is the reciprocal of the focal length. So if I’m using a FF sensor with lens 300 mm, a good benchmark is a shutter speed of 1/300 or faster. If I use a 300 mm lens with a DX sensor, does that reference change to 1/450 or is it still 1/300?
One more question. I think I know the answer, bu... (show quote)


I say 1/300.

| Reply
Page: <<prev 1 2 3 4 5 6 next>>
If you want to reply, then register here. Registration is free and your account is created instantly, so you can post right away.
UglyHedgehog.com - Forum
Copyright 2011-2019 Ugly Hedgehog, Inc.