Cropping Question: I have a Canon T5i with a 24-105 L lens. I have found that if I take a picture at 24mm, ISO 100, Aperture 8mm, and crop it 100%, it remains sharp. If, however I take...

MikeMck Loc: Southern Maryland on the Bay

I have a Canon T5i with a 24-105 L lens. I have found that if I take a picture at 24mm, ISO 100, Aperture 8mm, and crop it 100%, it remains sharp. If, however I take the same picture at 105mm with the same ISO and aperture, and crop it 100% it loses it sharpness.

I am sure this is a basic question, but I don't know the answer, thank you in advance.

joer Loc: Colorado/Illinois

MikeMcK wrote:

I have a Canon T5i with a 24-105 L lens. I have found that if I take a picture at 24mm, ISO 100, Aperture 8mm, and crop it 100%, it remains sharp. If, however I take the same picture at 105mm with the same ISO and aperture, and crop it 100% it loses it sharpness.

I am sure this is a basic question, but I don't know the answer, thank you in advance.

I'm a Nikon user but generally speaking lenses typically are not uniform throughout the zoom range. The lower range is usually sharper than the tele end.

Also focusing is less critical at the wide end compared to tele.

DOF is less at the tele end.

Clemens Loc: Maryland

Hello Mike,
Shooting a longer focal length is a little bit more critical than a wide angle.
Don't know what you are shooting or if you use a tripod or not.
Longer focal lengths may look to have a shallower depth of field because they enlarge the background relative to the foreground The out of focus background looks more out of focus because its blur has become enlarged.
Also shooting handheld you may need to increase the shutter speed with the 100mm (general rule is around 1/125 for this length) what may cause it to have more blur vs shooting 24mm

lighthouse Loc: No Fixed Abode

MikeMcK wrote:

I have a Canon T5i with a 24-105 L lens. I have found that if I take a picture at 24mm, ISO 100, Aperture 8mm, and crop it 100%, it remains sharp. If, however I take the same picture at 105mm with the same ISO and aperture, and crop it 100% it loses it sharpness.

I am sure this is a basic question, but I don't know the answer, thank you in advance.

You are lucky to have images left to work with after cropping like that.
Everything that I crop 100% just ends up as a white piece of paper. :lol:

Ched49 Loc: Pittsburgh, Pa.

When you shoot at the tele end hand held, camera shake can become a problem.

Delderby Loc: Derby UK

MikeMcK wrote:

I have a Canon T5i with a 24-105 L lens. I have found that if I take a picture at 24mm, ISO 100, Aperture 8mm, and crop it 100%, it remains sharp. If, however I take the same picture at 105mm with the same ISO and aperture, and crop it 100% it loses it sharpness.

I am sure this is a basic question, but I don't know the answer, thank you in advance.

You can see that I am a Panasonic MFT user, but my rules of thumb are:
1. don't bother to fully extend your zoom pull back say 10mm
2. aperture priority for wide angle, shutter priority for telephoto
3. be aware that most focus probs are in fact camera shake -
IS cannot do it all
4. auto focus at tele end will not always focus where you wish
5. if on tripod remember to switch IS off. :)

Festina Lente Loc: Florida & Missouri

Delderby wrote:

You can see that I am a Panasonic MFT user, but my rules of thumb are:
1. don't bother to fully extend your zoom pull back say 10mm
2. aperture priority for wide angle, shutter priority for telephoto
3. be aware that most focus probs are in fact camera shake -
IS cannot do it all
4. auto focus at tele end will not always focus where you wish
5. if on tripod remember to switch IS off. :)

Those are good rules of thumb, all five of them!

bull drink water Loc: pontiac mi.

I had thought that all things as equal as possible, long lenses were a tad softer than shorter lenses, was I wrong????

Festina Lente Loc: Florida & Missouri

bull drink water wrote:

I had thought that all things as equal as possible, long lenses were a tad softer than shorter lenses, was I wrong????

Perhaps. Depends on so much.
DOF and vibration are both "exaggerated" with long lenses (let's just sick to prime lenses for now), that it may more often appear that long lenses are less sharp than shorter lenses.
But that is not always so.

mutrock

Delderby wrote:

You can see that I am a Panasonic MFT user, but my rules of thumb are:
1. don't bother to fully extend your zoom pull back say 10mm
2. aperture priority for wide angle, shutter priority for telephoto
3. be aware that most focus probs are in fact camera shake -
IS cannot do it all
4. auto focus at tele end will not always focus where you wish
5. if on tripod remember to switch IS off. :)

Great basic advice that we all sometimes forget!

MikeMck Loc: Southern Maryland on the Bay

Thank you for all your suggestions.

LFingar Loc: Claverack, NY

MikeMcK wrote:

Thank you for all your suggestions.

You could try an experiment. Take both shots again but use a tripod, remote shutter release, IS off, mirror lockup and perhaps a shorter exposure. See if that changes your results.

MikeMck Loc: Southern Maryland on the Bay

LFingar wrote:

You could try an experiment. Take both shots again but use a tripod, remote shutter release, IS off, mirror lockup and perhaps a shorter exposure. See if that changes your results.

You know, great minds think alike, I did exactly that, except I forgot to take the lens off IS. Anyway, it did help. I guess being 69 means you tend to shake a little. thanks for your help.

Mike

JCam Loc: MD Eastern Shore

MikeMcK wrote:

I have a Canon T5i with a 24-105 L lens. I have found that if I take a picture at 24mm, ISO 100, Aperture 8mm, and crop it 100%, it remains sharp. If, however I take the same picture at 105mm with the same ISO and aperture, and crop it 100% it loses it sharpness.

I am sure this is a basic question, but I don't know the answer, thank you in advance.

Please explain how you can crop 100%.

If you give away 100% of your camera equipment, you don't have anything left, same thing goes with cropping. Do you perhaps mean you crop it to half size for example from 8 X 10 to 4 x 5?

lighthouse Loc: No Fixed Abode

JCam wrote:

Please explain how you can crop 100%.

If you give away 100% of your camera equipment, you don't have anything left, same thing goes with cropping. Do you perhaps mean you crop it to half size for example from 8 X 10 to 4 x 5?

Yes.
That is why I posted this.

lighthouse wrote:

You are lucky to have images left to work with after cropping like that.
Everything that I crop 100% just ends up as a white piece of paper. :lol: