I don't know who told you to shoot in manual mode, but I think that's was poor advice. Manual mode is not the best choice for this type of shooting, and a poor choice for the majority of photography. Basically, if the meter is working then manual mode is usually the wrong mode.
Since you have a Nikon, you should have shot in A mode, enabled your Auto-ISO, and set a Minimum Shutter Speed of 1/400s. Then you don't have to worry about ISO or shutter speed. If the shutter speed required for correct exposure is ever less than 1/400s, the camera will raise the ISO instead and maintain the shutter speed. This gives you the ability to manipulate aperture as you like, and also be protected from too slow a shutter speed, and you always shoot as the lowest ISO possible for the conditions. This frees you to concentrate on your subject and composition.
Man, you sometimes give good advice on here, but this is hilarious and wrong.
No, it's right on the mark. Your advice is incorrect.
1st off, I largely shoot wildlife, and I shoot 95% M Mode with Auto-ISO on. M Mode is NOT a poor choice.
Of course you can use M mode...choosing M mode doesn't stop the shutter from firing. But whenever a person is able to accomplish a task successfully, there's always an underlying question as whether he is successful because of what he does or despite of what he does. In your case it's in spite of what you do, and I would bet that you'd have more low-ISO shots if you switched to A mode.
2nd, you're suggesting that someone should menu-dive to set a minimum shutter speed of 1/400, rather than just flipping to M Mode and setting it? You think that's FASTER? Are you high? You just did the same thing as putting the camera in M Mode and selecting your shutter and aperture, only way slower.
You set the Minimum Shutter Speed once to match the current subject matter. Street photography and other snaps of people work fine at 1/60s, 1/320s works for most sports, and 1/500s is what I use for birds in flight. Once the MSS is set you don't have to change it unless your subject matter changes. Sure...Nikon should have made it easier, but there's no real disadvantage to the menu, other than a few seconds lost at the beginning of your shooting session. If set appropriately then you shouldn't need to change it while shooting. If the minimum shutter speed you need to freeze a BIF is 1/500s, I don't see how that would suddenly change to 1/250s in the middle of your shooting.
To the OP: M Mode with Auto-ISO is a GREAT way to go. It allows you to control both SS (for 1.5 x focal length, and/or subject motion), and Aperture size for DOF and/or sharpness control.
That's not a great way to use Auto ISO...in fact it's a poor way to use Auto ISO.
M mode with Auto ISO has two problems. First, you want to keep the ISO as low as possible...raising it only when necessary. With your method, ISO is always changing to give standard exposure at the current shutter/aperture combination. If you want to shoot at the lowest ISO, then you need to constantly manage your shutter speed. That's an unnecessary distraction. Auto ISO with A mode does that automatically.
Second, you must always pay attention to the ISO because once you bump into either end of the ISO range then you're going to have under or overexposure. This is why using Auto-ISO with A mode excels...you always shoot at the lowest ISO possible while being protected from under/overexposure.
When you're shooting you want to control the aperture and you also want to shoot at the lowest ISO possible. With Auto-ISO in A mode you have control of the aperture, and the ISO stays at its lowest setting, with the camera changing shutter speed to match the lighting. This prevents overexposure, and so you don't have to baby-sit your settings...you just set whatever aperture you want and shoot. If the lighting gets low or you decide to use a narrow aperture for deep DOF, then Auto-ISO will not allow the shutter to drop below your minimum shutter speed, and will instead raise ISO to maintain that speed. This ensures that you'll never use a shutter that's slower than the slowest shutter you're willing to use for the current subject matter, AND it ensures that you're always using the lowest ISO possible to meet your exposure constraints. And all this without you having to pay constant attention to the ISO and shutter speed. That's why Auto ISO with A mode is much better than with M mode.
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