# T3I Wide Angle Lens and Lighting



## USCRugbyNo1 (Mar 5, 2013)

I currently have a T3i and I just purchased a 10-22 mm wide angle.  I am going to be using this lens to shoot inside of homes as I am a real estate agent.  I don't have any external flash, but I do have a tripod.  Someone also mentioned that I should shoot level as it's very important with this lens.  I'm a noob so please be gentle!  I welcome all comments and questions!


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## pgriz (Mar 5, 2013)

So post something up and let us rip it apart!  Or not.  Or...  we can give you a virtual high-five if it looks really good.  Or we can shake our heads and ...  Ok, you get it.  Post some pics.


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## USCRugbyNo1 (Mar 5, 2013)

LOL I haven't shot yet.  I would rather get tips before shooting!  This is why I posted!


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## pgriz (Mar 6, 2013)

Lenses are like dogs.  You need to take them out for a walk on a daily basis, otherwise they get all pudgy and cranky and leave little messes in your camera bag.  By giving them their daily exercise, you improve their socialization by interacting with you, and you help them feel wanted by having them do what they love to do best - hunt light.  Now the challenge with a special breed like the 10-22mm, is that it can try to take on too much.  That is where your control as the alpha-dog comes in, keeping a firm (but not too tight) grip by having it sit on a tripod while you give it the right encouragement to look straight - level gives you straight lines. Especially at the wide end, it can be a little greedy and nibble at your toes.  And a proper diet of well balanced light, without too much brightness or dark areas will promote good digestion.  Really now - How can you train it if you don't take it out frequently?


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## USCRugbyNo1 (Mar 6, 2013)

pgriz said:


> Lenses are like dogs.  You need to take them out for a walk on a daily basis, otherwise they get all pudgy and cranky and leave little messes in your camera bag.  By giving them their daily exercise, you improve their socialization by interacting with you, and you help them feel wanted by having them do what they love to do best - hunt light.  Now the challenge with a special breed like the 10-22mm, is that it can try to take on too much.  That is where your control as the alpha-dog comes in, keeping a firm (but not too tight) grip by having it sit on a tripod while you give it the right encouragement to look straight - level gives you straight lines. Especially at the wide end, it can be a little greedy and nibble at your toes.  And a proper diet of well balanced light, without too much brightness or dark areas will promote good digestion.  Really now - How can you train it if you don't take it out frequently?



Understood, but I would do a LOT of research before buying a dog and taking him out to play!


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## Fuganater (Mar 6, 2013)

Depending on the lighting in each room you will most likely need the tripod and a pretty long exposure. Maybe even try some HDR shots to really get all the light you can. 

Hopefully your not shooting in auto so try to get a large aperture like f/16 - f/22 to get everything you can in focus. These will require a pretty long exposure time.


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## pgriz (Mar 6, 2013)

Fuganater said:


> Depending on the lighting in each room you will most likely need the tripod and a pretty long exposure. Maybe even try some HDR shots to really get all the light you can.
> 
> Hopefully your not shooting in auto so try to get a large aperture like f/16 - f/22 to get everything you can in focus. These will require a pretty long exposure time.



I'll have to disagree on the aperture.  Shooting at the low end of the focal length range gives you amazing depth-of-field even with relatively large apertures.  Using too high an aperture can kill fine detail due to diffraction.  The trick to shooting interiors in the daytime, is to have the interior light more or less equal to the outside light (so the windows are not blown out), and that means careful placement of your light sources.  As well, depending on the light sources, you can get objectionable WB colour differences if you mix outside light with inside light.  If you are using flashes to illuminate the area, then you have to think about reflective things in the room that can bounce back direct flash as objectionable glare, and if you're using bounce flash, then you have to check for the colour of the surface you're bouncing the light off.  It's tricky.  It makes portrait lighting look simple by comparision.


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## Fuganater (Mar 6, 2013)

pgriz said:


> Fuganater said:
> 
> 
> > Depending on the lighting in each room you will most likely need the tripod and a pretty long exposure. Maybe even try some HDR shots to really get all the light you can.
> ...



I'm no pro but if you aperture is at say f/4, you will have a shallower DOF than at f/16. Is that right or wrong?   (crap sorry to thread jack)


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## pgriz (Mar 6, 2013)

Fuganater said:


> pgriz said:
> 
> 
> > Fuganater said:
> ...



Using the DOF calculator (see here:  Online Depth of Field Calculator), you get the following:

T3i, 10mm, f/4:  The hyperfocal distance is 4.35 ft., and if you focus at that point, everything from 2.2 ft. to infinity will be in focus.  At f/16, 10mm, the hyperfocal distance is 1.11 ft., so that everything between 0.71 ft. to infinity is in focus.  For most interior shots, the closest item will be more than 3 ft. away, so you have more than adquate DOF even at f/4 to get everything sharp.

Same camera, 22mm, f/4:  Now the hyperfocal distance is 21 ft.If you focus at a point 10 ft. away, your DOF is between 6.8ft to 19.1 ft.  At f/16, the hyperfocal distance is 5.3 ft.,  and if you focus at that point, everything between 2.7 ft. to infinity will be in focus.

This shows that it is very important to know the DOF associated with the focal length, and to use this knowledge intelligently when deciding which aperture to use.  The aperture selection is also governed by trying to balance the exterior ambient light with the interior lights.  Let's assume the outside light level is mid-day bright, and therefore the f/16 rule applies (which says that using ISO 100, at f/16 the shutter speed should be 1/100).  Let's also say your flash sync speed is 1/200.  Let's say that you want the outside to be rendered "normally", ie, not too dim or too bright.  So your aperture will need to be f/11 at 1/200 sec.  You already know that you have more than adequate DOF from our calculation above, so now you concentrate on adjusting the flash power to give you a proper exposure at f/11.  That's how these kind of things get figured out.


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## Fuganater (Mar 6, 2013)

ahhhhhhhhhhhhhhhhhhhhhhhh. Shows how much I know about DOF 

Thanks for that lesson.


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## pgriz (Mar 6, 2013)

Fuganater said:


> ahhhhhhhhhhhhhhhhhhhhhhhh. Shows how much I know about DOF
> 
> Thanks for that lesson.



Heh, we're all here to learn.  Somedays we're students, somedays we're the teachers.  I like to share what I've had to learn the hard way - it might make someone else's life a little easier.


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## USCRugbyNo1 (Mar 6, 2013)

A lot of this is Greek to me!   :hail:

I love the link you provided, looks of great data there.  I selected my camera and then changed my focal length to 22 and got this information.


Subject distance 10 ft 
Depth of field Near limit 3.45 ftFar limit InfinityTotal Infinite In front of subject 6.6 ftBehind subject Infinite Hyperfocal distance 5.3 ftCircle of confusion 0.019 mm



Can someone please explain this information to me?  Does this mean the closest object should be *3.45 ft? *


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## Fuganater (Mar 6, 2013)

Means that anything from 0 ft to 3.44 ft will be out of focus. So ya, nothing closer than 3.45 ft


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## pgriz (Mar 6, 2013)

Depth of field is the zone of acceptable sharpness that is centered (more or less) on the point of focus.  In the example you've shown, your focus at 10 ft. gave you a depth of field ranging from 3.45 ft. to infinity.  The important number is the hyperfocal distance.  It says that if your lens is focused at a point 5.3 ft. away, then the far limit of your depth of field will be at infinity.  You could focus at 20 ft. and the far limit will still be at infinity, but now the zone of acceptable focus will be further away.  So the hyperfocal distance is the closest distance you should focus on to get the maximum depth of field.  If you don't actually have an object at 5.3 ft. you could either set the distance by using a tape measure, or by setting it on the lens barrel (assuming you have a lens with the distance scale on it).  Obviously, when you set the focus manually, you need to turn off the AF, as the camera will try to re-focus if you let it.


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## MetroRuss (Mar 6, 2013)

pgriz said:


> Lenses are like dogs.  You need to take them out for a walk on a daily basis, otherwise they get all pudgy and cranky and leave little messes in your camera bag.  By giving them their daily exercise, you improve their socialization by interacting with you, and you help them feel wanted by having them do what they love to do best - hunt light.  Now the challenge with a special breed like the 10-22mm, is that it can try to take on too much.  That is where your control as the alpha-dog comes in, keeping a firm (but not too tight) grip by having it sit on a tripod while you give it the right encouragement to look straight - level gives you straight lines. Especially at the wide end, it can be a little greedy and nibble at your toes.  And a proper diet of well balanced light, without too much brightness or dark areas will promote good digestion.  Really now - How can you train it if you don't take it out frequently?



I like your analogy. I also learned a lot from this thread and your posts.

Thanks everyone


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## TCampbell (Mar 6, 2013)

While it's true that aperture effects depth of field, as pgriz points out, focal length ALSO affects the depth of field.

I have a 14mm f/2.8 wide angle lens.  Even at f/2.8 I can focus the lens to about 3' and nearly everything will be in focus.  If I do that with a longer lens... say 100mm then very little outside my actual focused distance will be adequately focused.

Fuganater, keep in mind that aperture numbers are aperture sizes are inverted.  Large f-stop numbers represent smaller opens.  Small f-stop numbers represent larger openings.

There's a point where a camera becomes "diffraction limited" if you use apertures which are too high.  f/16 and f/22 are diffraction limited on an APS-C size DSLR which means they wont look as good as a middle aperture... say f/8 or f/11. 

MOST of the time you probably don't need to worry about being "diffraction limited" because it only shows up (things you expect to be very sharp are very slightly soft... focus isn't as tight as you'd expect) if you print BIG sized images.  For realty photos, which will probably be displayed on websites or in home listing magazines, the image sizes are usually not very large and you wont notice the effects of diffraction limits.  The bigger the sensor sizes (more specifically the bigger the pixel size) then the higher you can go with the f-stop value before having a diffraction issue.

For realty, don't worry about diffraction limits... for fine art photos that you plan to print big, frame, and hang in a gallery, then worry about diffraction limits.

The issue with keeping the lens axis level is because at wide angles you get wide angle distortions.  If the lens is level (lens is perpendicular to the surface of a door or window) then the door or window will look rectangular.  If the lens is not level then the door or window will be distorted and look more like a trapezoid... or even completely skewed.  It's not that you should NEVER allow the lens to be un-level... it's more that you should be AWARE of what will happen if it is un-level.  Sometimes not being level could be the only way to get the shot.  You can fix this problem in Photoshop fairly easily using either the "transform" tool or there's also a "lens distortion" correction tool.  But when using those tools, Photoshop will pinch one end of the photo and stretch the other so you end up with a "keystone" shaped image.  The image then needs to be cropped back to a rectangle (depending on the image you may actually be able to fill the corners... but you can't count on that.)  That means you need to leave lots of extra space around the edges of your image that you can afford to lose when the image is cropped.

I think one of the most difficult problems to solve is the lighting and this is especially true when shooting a room with windows.

Suppose you're shooting a room that has a gorgeous view to the outside.  You'd like to not just capture the "room" but also the "view" because it's a selling point.  The problem is... it's sunny outside and dark inside.  Outside you'd need a "Sunny 16" exposure (e.g. ISO 100, f/16, 1/100th sec) and INSIDE it's about 5-6 stops darker.  Each stop "halves" the light.  So 5 stops darker means you only have 1/32nd as much light inside... 6 stops darker means you have 1/64th as much light.  If you expose for the inside the outside is going to be totally blown out and all you see out the window is "white".  If you expose for the outside, you see the view but all you inside the room is "black".  

So how to get a well-exposed interior room with a well-exposed exterior shot AT THE SAME TIME?  That is a problem.

Unless you're a sorcerer, you probably can't do anything about the outside light.  But you CAN do something about the light inside.  You can supplement by bringing in lighting to bring up the interior light levels so that they're within 1/2 stop or 1/3 stop of the outside light.  Flash can easily do this.  But now you have a NEW problem... anything 'close' to the light will be bright and anything 'far' from the light (but still in the room) will be dark.  Each time the distance from the light increases by a factor of 1.4 (the square root of 2) the light is HALVED.  That means something 10' away with perfect lighting will look great.... something 14' away will only have HALF as much lighting.  Something 20' away will only have ONE QUARTER as much lighting.  To fix this... you need several of lights.

You can also try shooting the room with HDR.  HDR (High Dynamic Range) means you shoot several shots at different exposure values for the very same frame (varying only the shutter speed to change the exposure value).  The computer can then merge those together.  Shooting the shot in HDR is the easy part... then you need to learn to merge them so that the results look natural... which can take a bit of post-processing work and expertise to do well.  Usually the initial results don't look very natural.


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## USCRugbyNo1 (Mar 6, 2013)

At what height should you shoot rooms for real estate?


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## pgriz (Mar 6, 2013)

USCRugbyNo1 said:


> At what height should you shoot rooms for real estate?



Eye-level works the best, if you're trying to get prospects to visualize themselves in the setting.


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## pgriz (Mar 6, 2013)

The thing you have to be careful of with wide-angle shots in the interior, is that the wide-angle exagerates the separation between the foreground and background.  Normal-sized rooms look like bowling alleys when shot with a wide-angle.  So there is a danger that prospective clients would feel deceived if they were influenced by the "spaciousness" of the rooms.


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## USCRugbyNo1 (Mar 6, 2013)

pgriz said:


> The thing you have to be careful of with wide-angle shots in the interior, is that the wide-angle exagerates the separation between the foreground and background.  Normal-sized rooms look like bowling alleys when shot with a wide-angle.  So there is a danger that prospective clients would feel deceived if they were influenced by the "spaciousness" of the rooms.



Understood, but they can't make an offer on a house they haven't seen yet!  :lmao:


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