Dis PB Monthly Assignment, 8/09: Get out the tripods - Shutter Speed & Low Light

[ColleenG]

On the later pictures, why did you use the higher ISO?

On the pictures of the rides I went with ISO 800 cuz I changed for an earlier picture and forgot to change it back. Plus it was fairly crowded and I didn't have a lot of room to set up the tripod. I was looking back through my other shots and tried one at ISO 400 and it was too dark but I probably could have used a bigger aperature.

The first picture of the rides (the one with the woman's back to me) had a big glaring spot light just up and off to the left so that area was pretty bright compared to the other area where the other rides are.

 

[ColleenG]

No critique per se, just a couple of comments. I'm assuming you used a tripod - otherwise you've got very steady hands LOL! With a tripod you can keep the ISO settings low at 100 or 200 to keep the noise low in night shots. Just increase the exposure time to compensate.

Also, if you find yourself without a remote you can try using the timer so that you don't risk moving the camera pressing the shutter release.

Also, you posted that you used f/29 on the second shot? I haven't tested but I have read that most lenses start to lose IQ at that high of setting.

My favorite of your shots is the last one! You did a long enough shutter speed to show motion on the ride, yet for the most part stopped the motion of the people in the foreground which I liked.

This is right.. on APS-C, you start losing sharpness at apertures smaller than f/16 due to diffraction, no matter what lens.

Thanks for the tips! That's a great idea to use the timer. I honestly have no idea why I used f/29 on the one shot . I was just happy to be out alone and taking some shots with out everyone else moaning, "Come on, Moooom!" I definately need to do some more playing around. Hopefully I can get another night to sneak out alone with just my camera.

 

[Master Mason]

On the pictures of the rides I went with ISO 800 cuz I changed for an earlier picture and forgot to change it back. Plus it was fairly crowded and I didn't have a lot of room to set up the tripod. I was looking back through my other shots and tried one at ISO 400 and it was too dark but I probably could have used a bigger aperature.

The first picture of the rides (the one with the woman's back to me) had a big glaring spot light just up and off to the left so that area was pretty bright compared to the other area where the other rides are.

if it were me, I would have used a lower ISO and a longer shutter speed, it would have made the moving people basically disappear from the picture and would have given you the equal triangle you achieved by raising the ISO.

 

[ColleenG]

if it were me, I would have used a lower ISO and a longer shutter speed, it would have made the moving people basically disappear from the picture and would have given you the equal triangle you achieved by raising the ISO.

Thanks, I will give that a try. Hopefully it won't be as crowded the next time I go and I can set up the tripod.

 

[KAT4DISNEY]

This is right.. on APS-C, you start losing sharpness at apertures smaller than f/16 due to diffraction, no matter what lens.

Does this also happen on a full frame sensor?

On the pictures of the rides I went with ISO 800 cuz I changed for an earlier picture and forgot to change it back. Plus it was fairly crowded and I didn't have a lot of room to set up the tripod.

You DO have very steady hands!

 

[boBQuincy]

Quote:
Originally Posted by Code
This is right.. on APS-C, you start losing sharpness at apertures smaller than f/16 due to diffraction, no matter what lens.

Does this also happen on a full frame sensor?

QUOTE]


Yes, it happens on any sensor and film, and anything that has an aperture. Loss of sharpness due to diffraction occurs at any aperture smaller than wide open, it is just not very noticeable at wider apertures (where aberrations swamp out the loss of sharpness due to diffraction). Pixel pitch plays a big part in this, and a 15MP APS-C sensor shows significant diffraction issues even at f/8.

The good news: it is not like a switch, it is gradual. Sure, for best sharpness try for medium apertures like f/8 but if you need to go to f/16 don't worry that all of a sudden your image will be totally unsharp.

 

[Master Mason]

Quote:
Originally Posted by Code
This is right.. on APS-C, you start losing sharpness at apertures smaller than f/16 due to diffraction, no matter what lens.

Does this also happen on a full frame sensor?

Yes, it happens on any sensor and film, and anything that has an aperture. Loss of sharpness due to diffraction occurs at any aperture smaller than wide open, it is just not very noticeable at wider apertures (where aberrations swamp out the loss of sharpness due to diffraction). Pixel pitch plays a big part in this, and a 15MP APS-C sensor shows significant diffraction issues even at f/8.

The good news: it is not like a switch, it is gradual. Sure, for best sharpness try for medium apertures like f/8 but if you need to go to f/16 don't worry that all of a sudden your image will be totally unsharp.

Bob, Wouldn't it actually be worse on a full frame sensor using the same lens? On the APS sensor, the sensor is using a smaller section of the lens, and therefore more of the sweetspot, where the full frame uses more of the lens and therefore more of the edge comes into play. Or am I totally whacked in thinking that?

 

[boBQuincy]

Bob, Wouldn't it actually be worse on a full frame sensor using the same lens? On the APS sensor, the sensor is using a smaller section of the lens, and therefore more of the sweetspot, where the full frame uses more of the lens and therefore more of the edge comes into play. Or am I totally whacked in thinking that?

Not that whacked. Although the diffraction is not as bad on full frame (because the magnification required to make the same size print is less than for APS-C) the aberrations are worse because we are using more of the corners of the lens.

Also, to clarify one of my other points, diffraction does not get worse as MP count goes up (for the same size sensor) but our expectations are greater. It is generally considered that f/16 is about the limit for APS-C for a 8x10 print, but with 15 MP we are thinking more of 13x19 prints and that lowers the diffraction limit to more like f/11 or f/8.

It is all tied into the Circle of Confusion, which I always thought was our U.S. Congress!

 

[WDWFigment]

Bob, for that race car shot, were you panning at all (maybe even subconsciously?) If not, how did you get the car crisp with the background blurred? I'm curious as to whether there is another method besides panning...

 

[Pea-n-Me]

I sometimes feel like I'm inside the Circle of Confusion.

 

[boBQuincy]

Bob, for that race car shot, were you panning at all (maybe even subconsciously?) If not, how did you get the car crisp with the background blurred? I'm curious as to whether there is another method besides panning...

*Very* consciously panning! Most of my race car photos for this event were taken at 1/125 s with a 200mm lens. I used a monopod to help preserve sharpness from using such a long lens at such a slow shutter speed.
If all else fails we can add a layer, apply motion blur, and mask out the car to get that look of speed. It looks pretty good but is much more work than panning in the first place.

Here is one that was done with the "cheating" method:

 

[Code]

I did a bit more reading on diffraction, and I was only sort of correct in what I said before about APS-C and f/16. Turns out that's just a general rule and it depends on the lens. Consumer quality lenses that perform best when stopped down will actually perform better at very small apertures than will high end lenses that are very good wide-open. So a cheaper lens that is best at f/8 might not start seeing diffraction effects until f/16, but a pro lens that is best at f/4 might only go to f/8 before sharpness starts to drop.

Now on a different subject, here's a shot I took inspired by the theme:

Sony A700, 10mm, ISO 200, f/8.0, 30 sec

It came out very underexposed but I didn't want to stick around and risk waking the babies with more shutter sounds so I just boosted the exposure a lot in Lightroom making it a bit noisy, plus Nick is blocked by the crib and we only had Andrew's name up on the wall at the time. I'm definitely going to redo this shot as it's a great memory for us.

 

[Coach]

 

[ColleenG]

Here's one I took this past week. I shot some other ones in RAW but they were really out of focus. I didn't have a tripod, and the rest of the family wasn't really in the mood to wait around for me to play too much. It came out ok-ish.

ISO 1600, f/5, 1/5 sec, 40mm with my kit lens.

 

[Gdad]

Escalator- 6 Second Exposure

 

[dcg0317]

The Flume Gorge at Franconia Notch State Park in NH. Deep Gorge and very low light, used my Canon 17-40mm f/4 lens with a polarizing filter and a .9 ND filter stacked on the polarizing filter. Polarizing filter used manly to cut down on refelections off the rocks and water. All shot at ISO 100 with mirror lock up on a tripod with a remote shutter release and aperture priority, metering mode - pattern.

ISO 100
Sutter speed 10s
Aperture f/8
Focal length 37mm
AWB

ISO 100
Sutter speed 10s
Aperture f/8
Focal length 17mm
AWB

ISO 100
Sutter speed 5s
Aperture f/8
Focal length 37mm
AWB

 

[spinetnglr]

I have been wanting to try some moon rise shots and with a slightly cloudy evening with the full moon rising just before it got completely dark I thought it might be a good time to try it.

I was using a 70-300mm 4-5.6 lens. Shot at ISO 400

f5.6, 0.77 sec, 300mm

f10, 1/60 sec., 300mm

 

[kaffinito]

I have been wanting to try some moon rise shots and with a slightly cloudy evening with the full moon rising just before it got completely dark I thought it might be a good time to try it.

I was using a 70-300mm 4-5.6 lens. Shot at ISO 400

f5.6, 0.77 sec, 300mm

Absolutely gorgeous shot! I love this one!

 

[spinetnglr]

Absolutely gorgeous shot! I love this one!

Thank you kaffinito!!

 

[Gdad]

One Minute Exposure
Colored with Red and Blue Gel Flashlights