[Wasp]

I have to admit that I have never, ever used this mode. I really should give it a try.

[MrB1]

TAv can be a very useful and successful mode to choose, as others have noted above. However, take care not to select exposure settings that would take the ISO value beyond the ISO range that you have set in the camera.

For example, some people set 100 for the lower limit and 3200 for the upper limit (to keep noise low), but this is a range of only 5 stops, so selecting a fast shutter speed (to freeze subject motion) and small aperture (for good depth of field) could lead to under-exposure - if the ISO value is flashing you've gone out-of-range.

[clickclick]

I would add with Pentax's dynamic range and the great ability to pull detail out of darker areas in RAW, you can be "underexposed" because you pegged your high ISO limit and then in post get what you want. It's a great mode to use, as folks have already noted.

[Madaboutpix]

Gotta love TAv. I get to set both shutter speed and aperture where I want or need them, and the camera picks an ISO that it thinks will work with them. If the ISO rides too high for my taste, I can easily adjust T or A as needed.

Think of it as Smart Manual, or Manual with added benefits.

[Tas]

TAv can be a very useful and successful mode to choose, as others have noted above. However, take care not to select exposure settings that would take the ISO value beyond the ISO range that you have set in the camera.

For example, some people set 100 for the lower limit and 3200 for the upper limit (to keep noise low), but this is a range of only 5 stops, so selecting a fast shutter speed (to freeze subject motion) and small aperture (for good depth of field) could lead to under-exposure - if the ISO value is flashing you've gone out-of-range.

There's some salient points that you've raised here that should help the OP get to grips with using TAv mode.

I usually set my max ISO at 3200 and if I bounce off that limit will consider an aperture change first then either a slightly slower speed or bumping the ISO higher to 6400.

I don't want to go down the rabbit hole of ISO noise discussions as this is off-topic and a personal choice. Personally I prefer to get a better exposed image at the time of capture than raising things in post hence my approach. But even if you prefer to capture an image with some underexposure the actual subject needs to drive whether you stick with the lower ISO at capture then push in post, or raise the ISO for the capture IMHO YMMV etc.

This is all personal preference of course but I prefer some detail with noise to avoid needing to apply more NR and for my preferences this is often best met by running a higher ISO at capture. Of course, with masking options raising exposure in post, particularly with luminosity masking allows for minimising the potential of a noisier image so trying both approaches is a good way of 'hedging your bets' for getting the best captures possible.

Tas

[dafbp]

All of the above.
If you go to some sports photography event (like airshows), you'll hear the users from other brands setting either aperture or speed, and then fixing an ISO, meaning they rarely get the aperture or the speed they'd prefer.
With Pentax's TAv, that's not a problem.
Just watch the ISO every now and then to make sure you don't overexpose, or get more noise than you'd like.

Pentax should patent TAv mode.

[pschlute]

When i photograph my dogs in the garden with a long lens TAv is my preferred mode. I want a fast shutter speed to freeze their movements as well as to avoid camera shake with the long lens. Tv mode would work fine with even bright light, but in changeable light the aperture it would give me would be either too fast (not enough DOF) or too slow (too much DOF). TAv mode works perfectly. here is one I took yesterday with little Ripley.

K1 + DA* 60-250. 1/750 f5.6 ISO 1100 FL 250mm

[bkpix]

TAv for me is long-lens mode. Lock down a fast exposure and a mid-range aperture and float the ISO.

Main thing to beware of, as has been mentioned, is drifting out of the exposure range your settings can address. I shot day to day stuff in TAv for a while with the 15 Limited but found I was too often overexposing, which, of course, even Pentax can't handle in post-processing.

[reh321]

What is the purpose of TAv Mode on Pentax DSLRs? I have a Pentax K-3 but assume that other bodies have this mode too.

As adjusting one of the parameters affects the other how is this any different from using either Tv or Av Mode? '

In what situations might TAV mode be useful compared to either Tv or Av Mode?

Thank you!

TAv mode is kind of like using Tv and Av modes simultaneously - in TV mode you're saying that shutter speed is most important; in Av mode you're saying that aperture is most important; in TAv mode you're saying that both shutter speed and aperture are important, so ISO must balance the triangle.

In the Canikon world, you would get the same effect by using Manual mode with auto ISO.

A year ago I wouldn't have considered such thing, but the K-70, KP, and K-1 are delivering high ISO values, with minimal noise, so retiring my K-30 and getting a KP is sounding very good about now .... once I come up with the funding.

[Theov39]

TAv for me is long-lens mode. Lock down a fast exposure and a mid-range aperture and float the ISO.

Main thing to beware of, as has been mentioned, is drifting out of the exposure range your settings can address. I shot day to day stuff in TAv for a while with the 15 Limited but found I was too often overexposing, which, of course, even Pentax can't handle in post-processing.

Thanks Reh. That is a very clear explanation. Sounds from the posts here that it is a useful mode. I will try!

bkpix, good point about using it for long lenses.

[mikesbike]

I wonder if you have discovered the Pentax Hyper System-

When in P mode, if you'd rather have a different shutter speed or aperture than what the camera has chosen, just use your thumb or finger dial and select what you want, simple as that! First click freezes current value, subsequent clicks change value. This switches the camera into Tv or Av mode instantly without your having to first use the mode dial and then select your change. Very fast and efficient. A touch of the green button restores full Program operation. (Pentax Hyper Program)

When in Manual mode, you can use the green button to instantly set meter-centered exposure without having to twirl the finger and thumb dials in the usual manner. Then go from there. Especially fast when taking spot meter readings around a scene. After hitting the green button and getting your metered exposure, if you then prefer a different shutter speed or aperture, first hit the AE-L button and as you make your change, the other (aperture or shutter speed) will follow along to preserve the metered exposure. (Pentax Hyper Manual)

Another point: it is a good idea to implement Fine Sharpening for both the default "Bright" and the "Natural" categories in the Custom Image menus. Then leave your camera back on "Bright" for general use after making these adjustments. The sharpening level is already up by one notch by default in "Bright" and adding the Fine Sharpening brings greater fine detail in mages. You could also raise the sharpening level up one notch for "Natural" as well if desired, besides adding the FS.

[Theov39]

I wonder if you have discovered the Pentax Hyper System-

When in P mode, if you'd rather have a different shutter speed or aperture than what the camera has chosen, just use your thumb or finger dial and select what you want, simple as that! First click freezes current value, subsequent clicks change value. This switches the camera into Tv or Av mode instantly without your having to first use the mode dial and then select your change. Very fast and efficient. A touch of the green button restores full Program operation. (Pentax Hyper Program)

When in Manual mode, you can use the green button to instantly set meter-centered exposure without having to twirl the finger and thumb dials in the usual manner. Then go from there. Especially fast when taking spot meter readings around a scene. After hitting the green button and getting your metered exposure, if you then prefer a different shutter speed or aperture, first hit the AE-L button and as you make your change, the other (aperture or shutter speed) will follow along to preserve the metered exposure. (Pentax Hyper Manual)

Another point: it is a good idea to implement Fine Sharpening for both the default "Bright" and the "Natural" categories in the Custom Image menus. Then leave your camera back on "Bright" for general use after making these adjustments. The sharpening level is already up by one notch by default in "Bright" and adding the Fine Sharpening brings greater fine detail in mages. You could also raise the sharpening level up one notch for "Natural" as well if desired, besides adding the FS.

Thanks Mike. That is really good advice. I know about Hyper mode but the suggestions about adjusting manual exposure and image sharpening are a good ones. I will try that.

[pschlute]

As mike pointed out the Hyper system has a lot of good functions. One thing I can add is that when using the green button in Manual mode to give you a metered exposure setting, it is possible to select through the "E-dial programming" menu what parameter the green button should change when pressed (default is Tv and Av shift). As generally I am more concerned with aperture, I have mine set to Tv shift. So when in M mode a press of the green button shifts my shutter speed to give me the correct metered exposure leaving the aperture unchanged.

The Hyper system is a good one. I first used it 25 years ago on my Pentax Z-1

[gaweidert]

On my K1 I use it to keep my shutter speeds out of the dreaded shutter shock range while maintaining the aperture I want. If I need to be in that range then I switch to live view with electronic shutter. Hard learned lesson.

On my K3 or K5's I have used it as a somewhat more intelligent alternative to the PhD (Push here Dummy) mode. It's actually a pretty nifty (showing my age here) little tool.

[aaacb]

As others have pointed out, I also use TAv for outdoor sports and action, but also for concerts. If you are using similar shutter speeds all the time, you can probably mimic most of TAv's advantages with P + fast increase of ISO + shallow dof / action program curves (but that's a lot of settings ).

TAv is my main choice for concerts, especially those with dynamic lighting. For example, with a 50/1.4 lens I shoot wide open only when the light is so bad it will not allow anything else; otherwise I'll prefer deeper dof. In so-and-so light, I often change my shutter speed depending on how much movement there is, to squeeze into a lower ISO. With P-hyper this would discard my aperture setting. (If light is really really low, I then just use M set wide open, shutter around 1/60-1/125, ISO 800 and pray something can be recovered in post...)