EV Bar (K50)

ferry.ben · 10-13-2015, 01:35 PM

Evening all,

basically I up until now I have been using a Tamrom 70-300 with my K50, always on M mode.
I have just bought myself a Pentax 200mm f2.8 and was testing it also on M mode.

I noticed with the 200mm lens, the EV seems to automatically change it's value based on the ISO / shutter speed / f stop.
I find this strange given the camera is on M mode. Is this something with the lens, as when I again use the Tamron, the EV doesn't automatically adjust.

Thank you very much for any help.

Ben

Adam · 10-13-2015, 01:45 PM

Do you have auto iso enabled?

ferry.ben · 10-13-2015, 01:48 PM

Originally posted by Adam

Do you have auto iso enabled?

No. ISO is completely manual.
For example, my shutter speed is 1000 and ISO 1600. If the lens is pointed at a dark area the EV will move to -5, but if I turn to face a floodlight (sports photos), the EV will auto adjust.

Adam · 10-13-2015, 02:27 PM

Originally posted by ferry.ben

EV will auto adjust.

So your shutter speed and aperture change? They shouldn't. The light meter will just show the degree of over/under exposure based on the selected shooting settings and ambient light.

Adam
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Sideway · 10-13-2015, 09:00 PM

In M mode the EV bar displays the camera's meter reading based on the f-stop, shutter speed, and ISO (never had a K50 but I assume it'd work the same way). Now my question is why it doesn't do that with the Tamron?

mcgregni · 10-14-2015, 04:27 AM

The Tamron has an aperture ring. Is it possible it' was not in the A position? This would not send the aperture information to the camera and so the exposure indicator would not work ...?

**realitarian** · 10-14-2015, 07:01 AM

Originally posted by ferry.ben

Evening all,

basically I up until now I have been using a Tamrom 70-300 with my K50, always on M mode.
I have just bought myself a Pentax 200mm f2.8 and was testing it also on M mode.

I noticed with the 200mm lens, the EV seems to automatically change it's value based on the ISO / shutter speed / f stop.
I find this strange given the camera is on M mode. Is this something with the lens, as when I again use the Tamron, the EV doesn't automatically adjust.

Thank you very much for any help.

Ben

EV reading is not an adjustment, it is an indicator for you much like the horizontal and vertical levels are ('EV compensation', on the other hand, is an adjustment that you can make). On the 200mm, the EV meter is doing exactly what it is supposed to do.

When pointing to a dark spot it is indicating a negative value, meaning the frame is underexposed - so you'd have to increase the aperture and/or decrease shutter speed and/or increase ISO to bring the EV reading back to zero.

When pointing to a flood light, it should show a positive EV, meaning the frame is overexposed - so you'd have to do the reverse of the above (decrease aperture and/or increase shutter speed and/or decrease ISO) to bring down the EV reading back to zero.

Not sure why the EV reading did not move on the Tamron - how properly exposed were you shots before? Did you end up with a majority that were 'just not right' i.e. over or under-exposed? Maybe mcgreni's explanation is the reason.

dakight · 10-14-2015, 07:03 AM

The EV value shown on the display is nothing more than an indication of the exposure selected. Correct exposure would be 0, a negative EV means that your image will be underexposed at those settings while a positive EV means that it will be overexposed. It is the digital equivalent of matching the needle in an analog light meter. Your settings are not changing; the EV is just telling you where your exposure will be relative to ideal.

ferry.ben · 10-15-2015, 12:28 AM

Hi all,

sorry for the late reply here.
You were all right (of course). I had never seen this indicator move because as mcgregni said, my Tamron was never in A. I always prefer using the ring to adjust the f stop because until a few months ago I was using an old Super ME and it's just what I'm used to. The Pentax 200 doesn't have the aperture ring, therefore it was the first time the indicator could function.

Thanks so much for all of your help here and helping me learn something.

10-13-2015, 01:35 PM	#1
ferry.ben New Member Join Date: Apr 2015 Posts: 5	EV Bar (K50) Evening all, basically I up until now I have been using a Tamrom 70-300 with my K50, always on M mode. I have just bought myself a Pentax 200mm f2.8 and was testing it also on M mode. I noticed with the 200mm lens, the EV seems to automatically change it's value based on the ISO / shutter speed / f stop. I find this strange given the camera is on M mode. Is this something with the lens, as when I again use the Tamron, the EV doesn't automatically adjust. Thank you very much for any help. Ben

10-13-2015, 01:45 PM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,594	Do you have auto iso enabled? Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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10-13-2015, 01:48 PM	#3
ferry.ben New Member Join Date: Apr 2015 Posts: 5 Original Poster	Originally posted by Adam Do you have auto iso enabled? No. ISO is completely manual. For example, my shutter speed is 1000 and ISO 1600. If the lens is pointed at a dark area the EV will move to -5, but if I turn to face a floodlight (sports photos), the EV will auto adjust.

10-13-2015, 02:27 PM	#4
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,594	Originally posted by ferry.ben EV will auto adjust. So your shutter speed and aperture change? They shouldn't. The light meter will just show the degree of over/under exposure based on the selected shooting settings and ambient light. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

10-13-2015, 09:00 PM	#5
Sideway Senior Member Join Date: Dec 2006 Location: Taiwan Posts: 102	In M mode the EV bar displays the camera's meter reading based on the f-stop, shutter speed, and ISO (never had a K50 but I assume it'd work the same way). Now my question is why it doesn't do that with the Tamron?

10-14-2015, 04:27 AM	#6
mcgregni Veteran Member Join Date: Sep 2012 Location: Surrey, England Posts: 2,603	The Tamron has an aperture ring. Is it possible it' was not in the A position? This would not send the aperture information to the camera and so the exposure indicator would not work ...?

10-14-2015, 07:01 AM	#7
realitarian Site Supporter Join Date: Jun 2014 Location: Los Angeles, CA Photos: Albums Posts: 221	Originally posted by ferry.ben Evening all, basically I up until now I have been using a Tamrom 70-300 with my K50, always on M mode. I have just bought myself a Pentax 200mm f2.8 and was testing it also on M mode. I noticed with the 200mm lens, the EV seems to automatically change it's value based on the ISO / shutter speed / f stop. I find this strange given the camera is on M mode. Is this something with the lens, as when I again use the Tamron, the EV doesn't automatically adjust. Thank you very much for any help. Ben EV reading is not an adjustment, it is an indicator for you much like the horizontal and vertical levels are ('EV compensation', on the other hand, is an adjustment that you can make). On the 200mm, the EV meter is doing exactly what it is supposed to do. When pointing to a dark spot it is indicating a negative value, meaning the frame is underexposed - so you'd have to increase the aperture and/or decrease shutter speed and/or increase ISO to bring the EV reading back to zero. When pointing to a flood light, it should show a positive EV, meaning the frame is overexposed - so you'd have to do the reverse of the above (decrease aperture and/or increase shutter speed and/or decrease ISO) to bring down the EV reading back to zero. Not sure why the EV reading did not move on the Tamron - how properly exposed were you shots before? Did you end up with a majority that were 'just not right' i.e. over or under-exposed? Maybe mcgreni's explanation is the reason.

10-14-2015, 07:03 AM	#8
dakight Veteran Member Join Date: Sep 2014 Location: Phoenix, AZ Photos: Albums Posts: 1,216	The EV value shown on the display is nothing more than an indication of the exposure selected. Correct exposure would be 0, a negative EV means that your image will be underexposed at those settings while a positive EV means that it will be overexposed. It is the digital equivalent of matching the needle in an analog light meter. Your settings are not changing; the EV is just telling you where your exposure will be relative to ideal.

10-15-2015, 12:28 AM	#9
ferry.ben New Member Join Date: Apr 2015 Posts: 5 Original Poster	Hi all, sorry for the late reply here. You were all right (of course). I had never seen this indicator move because as mcgregni said, my Tamron was never in A. I always prefer using the ring to adjust the f stop because until a few months ago I was using an old Super ME and it's just what I'm used to. The Pentax 200 doesn't have the aperture ring, therefore it was the first time the indicator could function. Thanks so much for all of your help here and helping me learn something.

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