Rebel T5i ISO changing

I have another question. When shooting in manual and using flash I want to be able to change the ISO in my viewfinder so my meter will be whatever exposure compensation I want. For instance. I manual meter a scene indoors and I can turn the program dial for under or over exposure on the meter inside. However, is there a way I can adjust the ISO for over, under while still viewing the exposure meter in the view finder. When I hit the ISO button the ISO value comes up but then the exposure graph (what I call it) goes away and only the ISO is showing. Is there a button or a way to also change the iso in the viewfinder? Hope I'm making myself clear on what I need. I know some higher end cameras do it by the program dial and I'm hoping the T5I can do it also.

I'm pretty sue that there is no camera made by Canon that will maintain the metering while changing the ISO. I would also think that it shouldn't be too hard with a little experience to set the ISO value to within +-2 stops of what you need it any situation. In manual mode set the aperture/shutter combination that you desire to have, and meter. If you are within +-2 stops of your correct ISO the meter will tell you how many stops of ISO you need to add/remove to hit the exposure that you want. OK so you have to think about what you are doing in this scenario, but it's not exactly rocket science.

Most of the time once you have a little experience, it should be possible to hit the correct ISO to get your required shutter/aperture combination first time. The biggest potential issue that I see here is that you are still stuck using a reflected lightmeter for the ambient measurement, which if you are not careful with your metering still results in "chasing the needle" as the background tones change, even where the level of illumination is constant, changing the meter reading. The biggest problem is that thanks to the way that Canon's work internally in conjunction with ETTL II flash systems, the camera has to lock the ISO value in advance so that the pre-flash can be correctly metered, so you can't use Auto ISO, as that will just default to ISO 400.

If you really want to chase the needle like this in that type of situation I would suggest shooting in Aperture Priority mode and pick an ISO that will keep your shutter speed close to where you want it. You can then use the EC/FEC controls to balance the ambient/flash mix by +-2EV each. If on the other hand you are just trying to completely kill the background, i.e. ambient at below -2EV then just make sure that your chosen shutter speed/Aperture combination will allow you to pick an ISO that will get you below the -2EV mark, and then not worry too much about carrying on metering for ambient. You will then just be adjusting the flash output, be that the camera doing it with the ETTL II system, or simply by adjusting the power output of a manual flash system.

Personally when shooting in the studio with manual strobes I am shooting with ambient at below -2EV in Manual, and using the flash as the main light source. Otherwise I will shoot in Av, with an ETTL II flash for fill, and use EC/FEC to balance the light. I do though have my camera set up to keep the shutter speed in Av between 1/250, the max sync speed, and 1/60 so that I do not have to worry about very low shutter speeds causing camera shake. In that situation I would up the ISO if I felt I was close to hitting the 1/60 minimum and affecting the ambient/flash balance.

Alan

BigAl007 wrote in post #17976163
I'm pretty sue that there is no camera made by Canon that will maintain the metering while changing the ISO. I would also think that it shouldn't be too hard with a little experience to set the ISO value to within +-2 stops of what you need it any situation. In manual mode set the aperture/shutter combination that you desire to have, and meter. If you are within +-2 stops of your correct ISO the meter will tell you how many stops of ISO you need to add/remove to hit the exposure that you want. OK so you have to think about what you are doing in this scenario, but it's not exactly rocket science.

Most of the time once you have a little experience, it should be possible to hit the correct ISO to get your required shutter/aperture combination first time. The biggest potential issue that I see here is that you are still stuck using a reflected lightmeter for the ambient measurement, which if you are not careful with your metering still results in "chasing the needle" as the background tones change, even where the level of illumination is constant, changing the meter reading. The biggest problem is that thanks to the way that Canon's work internally in conjunction with ETTL II flash systems, the camera has to lock the ISO value in advance so that the pre-flash can be correctly metered, so you can't use Auto ISO, as that will just default to ISO 400.

If you really want to chase the needle like this in that type of situation I would suggest shooting in Aperture Priority mode and pick an ISO that will keep your shutter speed close to where you want it. You can then use the EC/FEC controls to balance the ambient/flash mix by +-2EV each. If on the other hand you are just trying to completely kill the background, i.e. ambient at below -2EV then just make sure that your chosen shutter speed/Aperture combination will allow you to pick an ISO that will get you below the -2EV mark, and then not worry too much about carrying on metering for ambient. You will then just be adjusting the flash output, be that the camera doing it with the ETTL II system, or simply by adjusting the power output of a manual flash system.

Personally when shooting in the studio with manual strobes I am shooting with ambient at below -2EV in Manual, and using the flash as the main light source. Otherwise I will shoot in Av, with an ETTL II flash for fill, and use EC/FEC to balance the light. I do though have my camera set up to keep the shutter speed in Av between 1/250, the max sync speed, and 1/60 so that I do not have to worry about very low shutter speeds causing camera shake. In that situation I would up the ISO if I felt I was close to hitting the 1/60 minimum and affecting the ambient/flash balance.

Alan

I was watching a wedding video by Joe Buissink and he said he likes to shoot in manual with flash to bounce but dials down the ISO to be -1 below the meter so the flash will not overpower the ambient light and he showed doing that on the camera and dial down the iso but the aperture and shutter stays the same, he keeps the on camera flash on ettl and really cuts the power of the flash to just a hint of flash because he bounces all the time. He was shooting with a 5D Mark II back then and I love his work right out of camera. So I was going to try it on mine but I can't figure out how to be looking thru the viewfinder to dial the iso up or down to be a -1 below the metered reading. He can dial up the iso and the needle (I call it) moves up or down the middle position for exposure compensation but it affects the flash output - don't know if I'm explaining it correctly. He meters manually and zeros the needle on the middle mark as being correct, he then while looking thru the view finder dials the iso until the needle is -1 below the middle mark. He dials it to a -2 outdoors for fill. He said that is the quickest to get to where you don't want to blow out the ambient, you want to keep the ambient and give just enough light to light the people.

I presume he is basically doing ETTL (expose to the left). Shoot in manual, get all your settings the way you want to center your meter, and the last thing you do then is set your ISO to one stop less. You don't have to shoot through the viewfinder to do this final step, get it set up correctly, then set your ISO 1 stop lower.

That is how I read what you posted.

The 1D3 and 1D4 can change ISO while metering is active. I assume 1Dx and 1Dx2 can do the same. I don't see how 1/60, f/4, 100 is that much different than 1/120, f/4, 200 though. What is it you are trying to accomplish? It seems like Manual exposure for ambient and FEC for flash will do what you want done.

TeamSpeed wrote in post #17976495
I presume he is basically doing ETTL (expose to the left). Shoot in manual, get all your settings the way you want to center your meter, and the last thing you do then is set your ISO to one stop less. You don't have to shoot through the viewfinder to do this final step, get it set up correctly, then set your ISO 1 stop lower.

That is how I read what you posted.

yes, just trying to find a faster way than doing all that. I have to take my camera either down from my eye and set it or when I press the iso button when looking thru the viewfinder it wipes out the exposure scale and only shows the iso, after I set it and let go of the iso button the scale comes back and I may have to re-adjust again,, etc. too long. Joe's way is faster and like the other poster said a few cameras will let you do that while the meter is active. I guess the T5i won't do that
it is much quicker to do it in viewfinder where I can see everything going on and just turn the dial.

Bassat wrote in post #17976528
The 1D3 and 1D4 can change ISO while metering is active. I assume 1Dx and 1Dx2 can do the same. I don't see how 1/60, f/4, 100 is that much different than 1/120, f/4, 200 though. What is it you are trying to accomplish? It seems like Manual exposure for ambient and FEC for flash will do what you want done.

I want to be able to set my aperture and shutter speed and then underexpose the flash by -1 stop. Main objective is to cut down on the flash power so it will not over ride the ambient as it lights the person(s). When Joe does it, the more he makes the ISO a - the less power the flash puts out when he bounces, so much so that when he bounced off a wall on the left you never saw the flash, it was so faint that it touched the people perfectly and lit them up so subtly and left the ambient alone, great result. Easier to do that in the view finder than messing with flash power, etc. while shooting a wedding and doing some formal poses - great short cut. He uses a 5D Mark III now and still a 580ex II.

Shooting wrote in post #17976590
I want to be able to set my aperture and shutter speed and then underexpose the flash by -1 stop. Main objective is to cut down on the flash power so it will not over ride the ambient as it lights the person(s). When Joe does it, the more he makes the ISO a - the less power the flash puts out when he bounces, so much so that when he bounced off a wall on the left you never saw the flash, it was so faint that it touched the people perfectly and lit them up so subtly and left the ambient alone, great result. Easier to do that in the view finder than messing with flash power, etc. while shooting a wedding and doing some formal poses - great short cut. He uses a 5D Mark III now and still a 580ex II.

The way I read this, you don't need to mess with the ISO, just pick one that works for your chose aperture and shutter speed. Camera in Manual mode. Select the aperture and shutter speed desired. ETTL-II will take care of the flash power/ISO thing if you just dial in the FEC you want. Dialing in effective flash power via ISO seems like a long walk on a short pier. Or I am missing the point entirely.

Shooting wrote in post #17976178
I was watching a wedding video by Joe Buissink and he said he likes to shoot in manual with flash to bounce but dials down the ISO to be -1 below the meter so the flash will not overpower the ambient light and he showed doing that on the camera and dial down the iso but the aperture and shutter stays the same, he keeps the on camera flash on ettl and really cuts the power of the flash to just a hint of flash because he bounces all the time. He was shooting with a 5D Mark II back then and I love his work right out of camera. So I was going to try it on mine but I can't figure out how to be looking thru the viewfinder to dial the iso up or down to be a -1 below the metered reading. He can dial up the iso and the needle (I call it) moves up or down the middle position for exposure compensation but it affects the flash output - don't know if I'm explaining it correctly. He meters manually and zeros the needle on the middle mark as being correct, he then while looking thru the view finder dials the iso until the needle is -1 below the middle mark. He dials it to a -2 outdoors for fill. He said that is the quickest to get to where you don't want to blow out the ambient, you want to keep the ambient and give just enough light to light the people.

So I started out writing out this answer to the above:

If you are dialing in your exposure, I assume with the camera set to an ISO value that is at least ISO 200, so that it is at whatever the "correct" level is should be, and then reducing the ISO by one stop, why do you still need to see either the shutter speed/aperture combination, or the metering level. In manual exposure mode, once you have set the shutter speed and aperture, making a change to the ISO value won't affect them. Also In manual exposure mode I can tell you exactly what the effect of reducing the ISO by one stop will have on the metering indication, it will indicate that the exposure is going to be one stop lower, which means the indication will move one stop to the left of where it was to start with. So why not just dial your settings to put the exposure indication in that position to start with. Then there will be no need to touch the ISO. At least that is what you are suggesting you want to do.

Then I realised that what you wanted to do was to just reduce the output from the flash system so that it gives you less of a fill effect. At least that is what you are implying in this next post.

Shooting wrote in post #17976590
I want to be able to set my aperture and shutter speed and then underexpose the flash by -1 stop. Main objective is to cut down on the flash power so it will not over ride the ambient as it lights the person(s). When Joe does it, the more he makes the ISO a - the less power the flash puts out when he bounces, so much so that when he bounced off a wall on the left you never saw the flash, it was so faint that it touched the people perfectly and lit them up so subtly and left the ambient alone, great result. Easier to do that in the view finder than messing with flash power, etc. while shooting a wedding and doing some formal poses - great short cut. He uses a 5D Mark III now and still a 580ex II.

To do this when using an ETTL flash all you need to do is reduce the FEC value. Set the FEC to -2 and the flash will be at two stops below ambient, set it to -1 and it will be at one stop below. This will work if you are shooting in either Manual or Aperture Priority exposure modes. Providing that you can get an exposure for ambient that is within your flash sync range. Although you could use HSS if your flash supports it.

On an additional note, if you want the background to be relatively darker than the flash (which is what the first half of this reply does), then use some negative EC, or set the exposure so that the meter indication is over to the left, and then use some positive FEC to being the subject up with the flash. With Canon ETTL II flash systems the cameras EC, or simply setting the exposure in manual to where you want it controls the relative level (brightness) of the ambient exposure. Changing the FEC changes the relative level (brightness) of the flash exposure.

Also remember that when using ETTL II, which is an auto exposure mode for the flash system, if you reduce the ISO of the camera, the flash system will simply INCREASE the flash output to compensate and maintain the same level of brightness from the flash part of the system in the resulting image.

Can I suggest that you set up a scene so that you can try some experiments. First set up your exposure in manual for the ambient, so that it is "normal" and then shoot some shots with the FEC set from -2 to +2 in one stop steps. The reduce the exposure for the ambient by one stop. Move the meter indication one stop to the left. Now repeat the shots using the FEC. In the second test you should see the ambient exposure on the background be darker by one stop, while the flash exposure changes with the FEC in both cases. The try the same test in Av, but instead use the EC control to add -ve EC to bring the background down in brightness, or +ve EC to brighten the background. Again the FEC control will do the same for the flash exposure.

Finally if in manual exposure mode, and with a flash with a constant power output, which would actually require a manual rather than ETTL II flash, reducing the ISO by one stop will simply reduce the brightness of the whole image by one stop.

Bassat wrote in post #17976607
The way I read this, you don't need to mess with the ISO, just pick one that works for your chose aperture and shutter speed. Camera in Manual mode. Select the aperture and shutter speed desired. ETTL-II will take care of the flash power/ISO thing if you just dial in the FEC you want. Dialing in effective flash power via ISO seems like a long walk on a short pier. Or I am missing the point entirely.

it is faster to do it right there by the program dial while looking thru the viewfinder than messing with other settings that have to be set back to normal when you want to go back to normal shooting...too many steps and easy to forget you changed something in the quickness of a fast wedding.

Faster to just hit a button and turn the dial while looking thru the viewfinder. It is always there in front of you as you look thru the view finder...no need to change other settings and have to remember to change them back. FEC does not show in the viewfinder but on the back of the camera, then you have to change that back to normal. I'm looking for faster and easier.

do you have a link to the video? i don't see how lowering the ISO would result in a lowering of the flash output...i'd think it would be the opposite...

BigAl007 wrote in post #17977110
So I started out writing out this answer to the above:

If you are dialing in your exposure, I assume with the camera set to an ISO value that is at least ISO 200, so that it is at whatever the "correct" level is should be, and then reducing the ISO by one stop, why do you still need to see either the shutter speed/aperture combination, or the metering level. In manual exposure mode, once you have set the shutter speed and aperture, making a change to the ISO value won't affect them. Also In manual exposure mode I can tell you exactly what the effect of reducing the ISO by one stop will have on the metering indication, it will indicate that the exposure is going to be one stop lower, which means the indication will move one stop to the left of where it was to start with. So why not just dial your settings to put the exposure indication in that position to start with. Then there will be no need to touch the ISO. At least that is what you are suggesting you want to do.

Then I realised that what you wanted to do was to just reduce the output from the flash system so that it gives you less of a fill effect. At least that is what you are implying in this next post.

To do this when using an ETTL flash all you need to do is reduce the FEC value. Set the FEC to -2 and the flash will be at two stops below ambient, set it to -1 and it will be at one stop below. This will work if you are shooting in either Manual or Aperture Priority exposure modes. Providing that you can get an exposure for ambient that is within your flash sync range. Although you could use HSS if your flash supports it.

On an additional note, if you want the background to be relatively darker than the flash (which is what the first half of this reply does), then use some negative EC, or set the exposure so that the meter indication is over to the left, and then use some positive FEC to being the subject up with the flash. With Canon ETTL II flash systems the cameras EC, or simply setting the exposure in manual to where you want it controls the relative level (brightness) of the ambient exposure. Changing the FEC changes the relative level (brightness) of the flash exposure.

Also remember that when using ETTL II, which is an auto exposure mode for the flash system, if you reduce the ISO of the camera, the flash system will simply INCREASE the flash output to compensate and maintain the same level of brightness from the flash part of the system in the resulting image.

Can I suggest that you set up a scene so that you can try some experiments. First set up your exposure in manual for the ambient, so that it is "normal" and then shoot some shots with the FEC set from -2 to +2 in one stop steps. The reduce the exposure for the ambient by one stop. Move the meter indication one stop to the left. Now repeat the shots using the FEC. In the second test you should see the ambient exposure on the background be darker by one stop, while the flash exposure changes with the FEC in both cases. The try the same test in Av, but instead use the EC control to add -ve EC to bring the background down in brightness, or +ve EC to brighten the background. Again the FEC control will do the same for the flash exposure.

Finally if in manual exposure mode, and with a flash with a constant power output, which would actually require a manual rather than ETTL II flash, reducing the ISO by one stop will simply reduce the brightness of the whole image by one stop.

Exactly. I don't want the shutter and aperture affected. If you have all the info there in front of you as you look thru the viewfinder, it would be so easy to just turn a dial to get what you want. Setting the FEC is something that you have to go set back to normal at some point, what if you get shooting quickly from scene to scene and you forget because it is not right there in front of your eyes, you have to remember it and then look at the back of the camera to see what you need to set back.

I don't want to change the brightness, I want to reduce the power to a -1 below your setting or below the manual metering of the scene - if I am bouncing to a wall or ceiling. Reduce the flash power so the ettl part will not read all that dimness and try to overpower the ambient. I want to reduce the flash power to just touch the people for a good flash exposure and leave the ambient alone. reducing it via the iso is really no different than having a remote and reducing it that way, when shooting ettl and you reduce the power the flash itself will not automatically put out more power to compensate. you are in effect doing the same thing when messing with the iso. I seen it done on the video the more the iso was adjusted to -1 or -2 below the manually metered setting the less power or less flash was put out. It may not be possible to what I want to do since you cannot change the iso while having an active metering in the viewfinder on the T5I like you can the 5D mark 2 and 3.

Shooting wrote in post #17977571
Exactly. I don't want the shutter and aperture affected. If you have all the info there in front of you as you look thru the viewfinder, it would be so easy to just turn a dial to get what you want. Setting the FEC is something that you have to go set back to normal at some point, what if you get shooting quickly from scene to scene and you forget because it is not right there in front of your eyes, you have to remember it and then look at the back of the camera to see what you need to set back.

I don't want to change the brightness, I want to reduce the power to a -1 below your setting or below the manual metering of the scene - if I am bouncing to a wall or ceiling. Reduce the flash power so the ettl part will not read all that dimness and try to overpower the ambient. I want to reduce the flash power to just touch the people for a good flash exposure and leave the ambient alone. reducing it via the iso is really no different than having a remote and reducing it that way, when shooting ettl and you reduce the power the flash itself will not automatically put out more power to compensate. you are in effect doing the same thing when messing with the iso. I seen it done on the video the more the iso was adjusted to -1 or -2 below the manually metered setting the less power or less flash was put out. It may not be possible to what I want to do since you cannot change the iso while having an active metering in the viewfinder on the T5I like you can the 5D mark 2 and 3.

I cannot see how this can possibly work. If you set the Aperture and shutter speed to any value you like, at some ISO value that is above 100, actually to go minus two stops it would have to be at least ISO 400, and reduce the ISO by one stop all that will happen is that the brightness of the ambient lit part of the image will become one stop darker. If you have an ETTL II flashgun mounted, be it set for direct or bounce flash, if you make no change to the flash controls the fact that the ISO has been reduced will be noted by the camera, so that it will increase the power of the flash by one stop. That is the whole point of ETTL II flash auto exposure.

Even if what you wanted to do would happen if you are in Manual Exposure mode, setting the ISO to 400 and then using the camera's TTL metering system to set the exposure so that the indicated exposure is set to the "0" mark in the center of the dial might give you for example 1/125s for the shutter speed and f/5.6 for the aperture. If you now reduce the ISO to 200, which is what you say you want to do, if you leave the aperture and shutter speed alone, the metering indication will now read -1, or One full notch to the left of center. So why not simply skip the setting to ISO 400 and centering the meter, then reduce the ISO, and simply set the ISO to 200, and using the meter set the shutter and aperture to read -1 on the scale. You will still end up with 1/125 and f/5.6 set on the camera with an ISO of 200. In a manual exposure mode the camera simply doesn't care how you arrived at the setting that you are using.

I suppose you could possibly get what you want if you set the manual exposure at +1 on the meter, then engage the FEL to lock the flash exposure, then reduce the ISO by one stop. That would have the effect of reducing the flash output compared to the ambient exposure. That is if the FEL will remain in place as you change the ISO. Exposure lock or even FEL is not something I would ever use. If I want the exposure locked then I use manual settings, that I can be sure will only change when I change them.

I have to say that if you are shooting weddings for money, and can't remember that you set some FEC for a shot, and need to reset it to "normal" afterwards, simply because the camera isn't telling you so, you probably shouldn't be doing them.

Alan

DreDaze wrote in post #17977568
do you have a link to the video? i don't see how lowering the ISO would result in a lowering of the flash output...i'd think it would be the opposite...

No, it was a 3 day Creative Live seminar with Wedding Photography with Joe Buissink that a friend of mine loaned me. He said that adjusting the iso so the meter is -1 below the metered scene is what does it so it could be raising the iso also, just adjust the iso until the meter is -1 under the metered scene and it worked.

BigAl007 wrote in post #17977772
I have to say that if you are shooting weddings for money, and can't remember that you set some FEC for a shot, and need to reset it to "normal" afterwards, simply because the camera isn't telling you so, you probably shouldn't be doing them.

Alan

Then tell that to Joe Buissink who is more successful than many of us will ever be. On youtube you can watch a video called Joe Buissink back to basics and in it he explains how and why he shoots P mode about all the time also.