What is the maximum distance for getting good SHARP pictures on a telephoto lens?

[supercool2]

HI, maybe I asked the wrong question above in my title. But here is my issue:

I had this problem with every zoom/telephoto lens I have tried so far. I tried a 18-200mm lens (kit lens,so higher apurter #'s), a Tamron 70-200 2.8 ,and now a nikon 70-300(higher aperture #'s (4-5.6 I believe) is doing the same thing. It still didn't matter with the 2.8 lens either.

When I try to get a picture of a person,pet,or thing from far away, and then zoom in up to their face/body in my ViewNX 2 program (I don't have photoshop,and can't figure out lightroom) , it is very grainy/not sharp on the computer (or even on the camera's screen). I am going to post some examples. The first I took in manual or user 1 mode. The second of my Dog was taken in fully auto and I never used auto before today. I did fully auto to see if it was something I was doing wrong, and maybe the camera would get right.
I noticed when I am MUCH closer to the subject distance wise, I don't have much of a problem with getting the picture sharp, especially when flash is used. But I thought the whole reason for a telephoto was get pictures of far away things. And at the distance I'm using, the flash wouldn't work (about 50 feet+) .

So far the only lenses I have been happy with in terms of sharpness, are my 50mm (and I don't use that one hardly ever anymore) and 85mm 1.8 . I LOVE my 85mm 1.8. I can use that lens at f6+ and the picture comes out to my satisfaction nice and crisp as if it were 1.8. So it's not just the lower fstop #'s on it. I'll also include 2 pictures from my 85mm to show how clear the people's faces are. One at f1.8 and one at f6.7

Well,doing it fully auto didn't make a difference. These first two are straight out of the camera. The only thing to first two was convert to jpeg to resize so they would fit in my post here. Those are from the 70-300 lens.



View attachment 53384View attachment 53385



These two, I can zoom/magnify to x1.0-x2.0 in the viewnx 2 program to get a closer look, and the eyes and everything is still crisp&clearer than the above two pictures.
pictures from 85mm I only edited in the viewnx 2 program, but minor things like lowering exposure,sharpening, etc..

View attachment 53386



View attachment 53387

 

[Big Mike]

The longer the lens/focal length, the more camera movement becomes an issue. Just as an example, pick up a broom and hold just the end of the handle while holding it out horizontally in front you. The other end of the broom will be moving around because you (or anyone) can't hold it perfectly steady.

Sure, that is an exaggerated example, but the principle is basically the same.

So the key thing to keep in mind, is that when using a longer lens, you need to do either of two things. First would be to stabilize the camera as best you can. Good posture and technique are a good start but to really get the maximum sharpness, you should use a tripod (along with good tripod techniques).

The other thing you can do, is to use a faster shutter speed. The 'old' rule of thumb (for 35mm format) is that you want your shutter speed to be at least the reciprocal of the focal length. So if you are shooting at 300mm, you would want (need) a shutter speed of at least 1/300. Now, consider that your camera has an APS-C sized sensor, so the resulting images is a smaller FOV than 35mm format (by a factor of 1.5)....so it would be a good idea to factor that into the equation. So shooting at 300mm, you should be using a shutter speed of at least 1/450.

To take that a step further....this rule goes back to the days of film, where we would judge our sharpness by looking at prints or maybe at a tiny negative. But what do you (we) do now? We put the digital image on a computer and zoom in to 300%. In other words, we are harsher critics of ourselves (in terms of sharpness) than photographers were 20 years ago.

So what I tell my students, is that they should shoot for a shutter speed that is 2X the focal length. So if you are shooting at 300mm, you would want a shutter speed of 1/600 to ensure sharp photos (to mostly eliminate blur from camera movement). If you try that, I'm sure you'll find that it's very hard to do, unless you shoot in very bright light or raise your ISO to really high levels.
In many cases, it just won't be practical. But you should still keep in mind that a faster shutter speed is very important with longer lenses...and the more you can stabilize the the camera/lens, the sharper the photo can be.

 

[KmH]

The image sensor in your camera has an anti-aliasing filter (also known as a low pass filter) in front of it.
That filter softens image focus so edges don't have 'jaggies' from pixel edges.

Lens quality can also be an issue. Camera Lens Quality: MTF, Resolution & Contrast
As can be lens aperture, particularly when the aperture is small - Diffraction Limited Photography: Pixel Size, Aperture and Airy Disks

Consequently, the sharpness of every image you make can be improved by applying sharpening.

How, how much, and what type of sharpening should be applied is a fairly complex book length subject - Real World Image Sharpening with Adobe Photoshop, Camera Raw, and Lightroom (2nd Edition)

Sharpening & Detail

• Understanding Sharpness
• Guide to Image Sharpening
• Sharpening Using the "Unsharp Mask" Tool
• Using Local Contrast Enhancement

 

[tirediron]

Could you also post full EXIF data to accompany those images?

There are a number of issues that may contribute to your problem. First of all the 18-200 is NOT at its best at either 18mm or 200mm, so it's entirely possible that is as good as it will get. Additionally, NO lens is at it's best wide open (at largest aperture). Typically for maximum sharpness, you should stop down at least two stops; f8-11 is generally a good range for most lenses, 'though the higher quality zooms and primes will deliver better results at larger apertures.

Shutter speed is also a consideration. Most people cannot hand-hold longer lenses still enough to produce sharp results at slower shutter speeds. The guideline is that the shutter-speed should be at LEAST 1/FL, so if you're shooting at 200mm, then your shutter-speed should be a minimum of 1/200th of a second, and ideally faster.

 

[amolitor]

It sounds like you're taking picture where the subject is quite small in the frame, and then you're zooming in on that in the photo editor afterwards?

This is going to produce softer pictures, for sure. You're throwing away a lot of the megapixels when you zoom in. Walk closer to the subjects, so they fill the frame, before you take the picture!

 

[cgipson1]

Longest distance for sharp telephoto images? I have some of the MOON.. does that count?

We need EXIF, as mentioned! Top quality glass helps....

These look more like technique issues... post the Exif, and how you shot them....

Were these cropped at all? How much? What software you you using for post? How do you sharpen?

How do you have your camera setup for focusing? Spot focus, matrix, center?

 

[KmH]

Additionally, NO lens is at it's best wide open (at largest aperture).

I respectfully disagree that NO lens is best wide open.

The issue with 'fast' (generally up to f/2.8) wide apertures is that more of the outer portions of lens elements are used. A simple lens gets thinner towards the edge and the thinner glass focuses the image at a very slightly different distance than the middle of the lens.
Additional lens elements are added to correct that and other optical aberrations.

So some of the better 'fast' wide aperture lenses are quite sharp when used wide open.
While most kit lenses are not as effectively corrected, they are in effect already 'stopped down' to the beginning of their sharp focus sweet spot aperture range.

Zoom lenses have to be designed such that they make design compromises through the zoom range.
Superzoom lenses (10x+ zoom range) have to make the most compromises. Virtually all the 18-200 and up zoom lenses have significant image quality issues at various focal lengths in their range because of all the design compromises that much zoom range entails.

 

[supercool2]

I have a D7100. i thought it does not have a low pass filter.

The image sensor in your camera has an anti-aliasing filter (also known as a low pass filter) in front of it.
That filter softens image focus so edges don't have 'jaggies' from pixel edges.

Were these cropped at all? No How much? What software you you using for post? view NX 2 . How do you sharpen? view nx 2 ,and only slightly if I feel it's needed because I don't like to over do that.

If the picture doesn't look sharp to begin with and is fuzzy like those, I usually just delete them all together, because any sharpening after the fact doesn't usually help.

I said above there was no editing at all with the first two pictures. they are straight out of camera. I changed them to jpeg for resizing for posting on this forum and because I don't know if the forum will let me upload large files like raw. With the last two pictures there is no cropping, and very minimal editing. At most, just slight adjusting of exposure/sharpening in the View nx 2 program. That's it. No other editing,no photo shop, nothing. I don't know how to use lightroom,and I not only don't know how to use photoshop,I won't spend the $ on that program until i learn to use that program first.
I tried it once when my laptop came with photoshop elements a few yrs ago and I couldn't figure it out at all.
How do you have your camera setup for focusing? Spot focus, matrix, center? Spot. I will switch to continuous if I know it's a moving object like a car,or my almost 2 year old running around. but it's always on spot . I'll see the forum will let me upload the original raw pictures so you can see the data. Otherwise I'll have to write it down ,because it won't let me highlight it with my mouse to copy and paste.

 

[supercool2]

"info" data for first picture in view nx 2 program when looking at the raw file:

8/20/2013 23:19:58.30
Nikon D7100VR 70-300mm f/4.5-5.6G
L(6000x4000) DX-25.3 MB
280mm- Auto (ISO 160)
1/250s- f 5.6
OEV- Auto 1,0,0
This just had the auto ISO, but I was using manual or user 1 mode (can't remember)





"info" data for second picture in view nx program when looking at the raw file:

8/21/2013 22:26:13.30
Nikon D7100
VR 70-300mm f/4.5-5.6G
L(6000 x 4000) DX - 28.7 MB
300mm- Auto (ISO 800)
1/125s - f5.6
This was set to the fully "auto" mode with auto iso

Is this the exif data? How do I find it,if not ?


edited to add:
Do prime fixed lenses normally produce much sharper images ?
edited again to say: when on spot focus, I always focus on the eye/eyes/face

 

[Braineack]

I think 1/250 and 1/125 was just too slow for the 300mm.

Here's a shot I took at 200mm at 1/2000, f/5, iso 400:

same lens, same day but this shot was done at 300mm, 1/125, f/5.6, iso 100:

only his belt and keyring appear to be sharp when zoomed in.

 

[Designer]

only his belt and keyring appear to be sharp when zoomed in.

Well, here's yet another thing that will affect the (perceived) sharpness. Your camera focuses on something that contains a high-contrast edge, so in this shot the belt is in focus, while the face is not. You can select which area of the image that the camera uses to focus by going into the menu and selecting which focus point to use.

 

[The_Traveler]

If you shot these in raw and did no sharpening during the conversion, it will always look less sharp than it could because camera firmware de-mosaics the image thus blurs it a bit.
Raw images MUST BE sharpened; that's not a preference but a fact of the process.

 

[Braineack]

Well, here's yet another thing that will affect the (perceived) sharpness. Your camera focuses on something that contains a high-contrast edge, so in this shot the belt is in focus, while the face is not. You can select which area of the image that the camera uses to focus by going into the menu and selecting which focus point to use.

Almost positive i focused on the face, it was shot in full manual mode and I always aim for the eyes when focusing on something, well, with eyes. But it's also a 50-300mm and its autofocus is nothing to write home about.

I'm pretty sure had the focus remained the same, but I shot at say 1/1000, he would have been in full focus. IIRC he just started moving/walking as I took the shot and I think I captured motion blur on his upper half.

Anyways...

 

[kathyt]

Longest distance for sharp telephoto images? I have some of the MOON.. does that count?

We need EXIF, as mentioned! Top quality glass helps....

These look more like technique issues... post the Exif, and how you shot them....

Were these cropped at all? How much? What software you you using for post? How do you sharpen?

How do you have your camera setup for focusing? Spot focus, matrix, center?

Any other questions for him Charlie? What size shoe do you wear?

 

[orb9220]

Seems simple enough first two images cloudy and questionable shutter speeds.
Lest contrast for consistent AF lock on intended point.

Last two images bright light more consistent contrast for AF to grab onto.

Not surprised as shot many situations with this lens. And VR is great for static shots. And being a slower variable f-stop lens.
Not so great for people and motion at slower shutter speeds. For people would be looking up in the 1/500th of a second for freezing motion.

Being the D7100 would have cranked up the iso to get better shutter speeds for people and cloudy lower light situations.
.