Playing with the f stop on the SLOW (Dial up warning!)


rhoward

S.L.O.&W. Trainman
After having the Canon Digital Rebel XT for over a year, I decided after talking with a friend of mine who is a pro photographer, to actually sit down a see what I can do with it. I have been experimenting with the manual settings particularly the f stop to increase depth of field. Here are two photos taken in basically the same spot (I redid the zoom between the first and second. Both were taken with the standard kit lens that comes with the camera. I have corrected the color balance for the lighting on the layout (and added lights for the shoot). Also they were severely reduced in size in order to post them here (you don't want to download 22 Mb images now do you....) Your constructive comments would be appreciated.

The first is taken at f22.

HopewellTestf22w.png


The second at f29 (as high as this lens allows).

HopewellTestf29w.png
 
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light

F22 sure makes a difference. How did you measure your light ? Your contrast is high and that has a tendency to go beyond the limits of your CCD. A digital camera has the same limited brightness range as color positive or slide film. Soft light is what you need.


Larry.......retired fashion photographer
 
The only difference my untrained eye can see is maybe a little more crispness in the foreground of the f29 picture. I do see what Larry says about the light, but I doubt I would have come up with it on my own.

Heck,in my basemnt, by the time I stop down to f16 with my Fuji, I'm hurting for any light at all.
 
I don't have a light meter so it was done with the stuff in the camera. I did adjust the curves on the image. Could it have done what you describe? The original appeared to be somewhat under exposed.
 
Soft light may look flat to the average on looker because our eyes have this FABULOUS brightness range. You have to learn to think like a camera. When I had my studio I would measure incident light down to the 1/4 step and balance my light to half a step. Exposure is MOST important.
Focus your image at a point that is one third of the distance from the lens to the background. You can put a target there to focus on and remove it before you take the picture. But focus at f 2.0 or as close to that as you can get. Then change to f22 or 29 to take your picture

Larry
 
Bread&steel, thank you you have been very helpful! Here are 3 more as follows. These are straight from the camera (resized for viewing here).

Shot at f22 Color Balance set to automatic:

HopewellTest03f22w.png


Shot at f22 Color balance set to Tungsten with only the 2700°K CFL layout lights on:

HopewellTest04f22w.png


F22 with Color Balance set to Tungsten, layout CFLs and 100W Tungsten light on:

HopewellTest05f22w.png


Care to comment on them?
 
The first one looks a little too warm to me (yellow), and the last too cool (blue). The middle looks like bright daylight. A little stark, maybe, but the best of the three you presented. I guess it depends on your intent. Any of the three could work depending on your intent and context.
 
I agree the middle one looks best.

My camera has been giving me fits! Whenever I have it in "apurture priority" mode and have it on one of the narrowest settings (f28-f32), the exposures ALWAYS come out way too dark and I'm forced to brighten my images (via Photoshop) by ~150%.
 
Ken,

I don't know the Cannon, but on my Fuji there is a way to increase (or decrease) the exposure. I'll bet there is a way for you to do it.
 
Ken,

I don't know the Cannon, but on my Fuji there is a way to increase (or decrease) the exposure. I'll bet there is a way for you to do it.

On the Canon EOS Cameras there is a light meter built into the camera. You can increase or decrease exposure manually according to what is needed for whatever f stop you are using. That is what I have been working with as well as the color balance of the camera. I learned a lot about the capabilities of the rebel yesterday. I had been adjusting the photo using photoshop and I now see that I am beter off doing it in the camera and making minor adjustments in photoshop as needed.

Chip, the effect I don't care for is the first photo which is much too yellow for my tastes but reflects the K temp. of the layout lighting. When you are looking at the layout, it doesn't look bad but in a photo it is off. I have been adjusting color visually using Photoshop. I works better, I think, using the camera. I have also been lightening the space in photoshop as well. Again, with better settings on the camera, I think I am getting better results.

Thank You, everyone, for you comments. Keep them coming!
 
Again, I can't speak for the Cannon, but on the Fuji you can make custom settings to the white balance. What the photog that sold me my camera does is use a white board in the light you are using then adjusts the white balance until it looks like the white board.

My guess is your camera can do the same.
 
Hi Ray,
I'm new to the forum but a pro photographer too and I've have been shooting digital for the past five years so I wanted to make a few suggestions to try and help you.

1st. I would highly suggest that in the beginning you let the camera adjust/
set the the light balance unless you have placed a white card, 8.5x11.5" approximately in the scene and white balanced using it whatever lighting you plan to use to take your shot? It seemed you mentioned two different choices but stick with one at a time for a few test shots.

2nd. Use the automatic mode to start with until your getting the results that look pleasing and the most accurate to you. In the shots you've posted you know better than any of us which looks the best with the truest colors of your layot.

3rd I'm not sure but in the beginning you may have had your iso set too high, probably you can use an iso setting of about 200 +/- and still shoot at a reasonable shutter speed. Too high of an iso will cause the scene to look very light or of course if you played with a slow shutter speed setting that could do it also. As Larry, I think said, focus using a larger aperatue which will be automatically done for you unless your working in manual mode.

4th Set your camera for Aperature Priority and let the camera set the shutter
speed it needs, if it seems too slow crank up the iso one notch higher, from 200 to 400.

5th You mentioned a 22mp file size, without meaning to be belittling, that is over kill indeed, I imagine your Rebel has about an 8mp sensor and for shots to post or even print a 4mp JPEG image is more than sufficent to produce a file that will post a fantastic image or print a beautifully sharp and detailed 13x 19" print, I do them all the time from a 3.5mp JPEG file size.

6th As it was stated before, determine what/where your subject is and focus on something that is approximately 1/3 the depth of your overall scene. The reason for this is that for any given camera to subject distance, as well as Aperature setting,to the main subject, say the Red caboose, you'll have 1/3 Depth of Field [DoF] in focus in front of the subject and 2/3 behind it. Now if you move back a little farther from the subject, the caboose, your depth of field will increase, move in closer and it decreases.

I believe your camera has a DoF button on it to the right of the lens and when pressed you be able to see the DoF your getting

In the begining keep it simple and let the camera adjust most of the settings for you. Try this and I think you'll have better luck.

HTH

David
 
I just wanted to add a quick little blurb on this...

Having everything in focus is great... but not always needed... if you experiment with less DOF and adjust your focus point accordingly you can allow the wall to become blurred out and give it a more realistic effect of not being a layout... just food for thought...
 
Bob, what are you using for lighting in that photo? The ones I posted at WPF this week I replaced the CFLs (2700°K) with tungston 40w and 100w bulbs in the overhead lighting nearest to the site I was photographing and the results IMHO came out much better. Also, what lens are you using for Macro work? And Yes, the thing I am working on is Depth of Field.

Thank you all for your suggestions.

note to Trussrod: Just an FYI... I am not at all new to digital photography as I got my first digital camera almost 10 years ago. This is my first DSLR though. I have owned it for a year and have taken around 5000 shots with it so far. Most of them were in fully automatic, sports mode, or Macro mode. Those generally work fine for outdoors quick action photos that I most commonly do. Several hundred of the photos have been or will be used by several camps nearby for promotional materials. Our local Boy Scout Council asked me (hired me) this summer to photograph each of their camps to create files for a series of promotions for their upcoming Capitol Campaign for camp. Much of what you suggest, while very good advise falls into the "Been there, Done that" category. What I am trying to improve are my model photos which can't be done well given the lighting, etc. on the layout using the automatic modes.

I also own a small retirement business producing professional recordings for area Schools, Churches, and some other local groups (I do everything in house from original recording to production of the CD or other media). In my business I specify a minimum of 300 DPI at printing size. I prefer 600 DPI as that is what my printers generally are set at. (These are the same specs required by the local newspaper for photos they print even in the newspaper.) A 3.5 Mp shot a "beautifully sharp and detailed 13x 19" print"? Not by my standards at least. And I mentioned 22 Mb (that's MegaByte) file size. Not sure where that came from as a full sized 8Mp photo as downloaded to my computer runs around 4.1Mb as a jpg. It may have been from think in terms of TIFF which I use for printing often.

I will keep in mind your suggestions, as they do have merit!
 
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I like the last two, with mild preference for the middle...kinda. Ray, it would be useful to get even more light onto the subject to get that full sun effect IMO. To me, it needs brightening. Maybe my lack of general knowledge about the subject prevents me from using the right choice of terminology to express what I mean....but to me it needs to be brighter.

Dayum, though, you have a nice layout coming along there.
 
Hi Ray,
I wanted to mention a couple of other points, Orgnoi1 makes a very good point in that not everything needs to be in sharp focus unless that's your intention. As an example lets use the Red Caboose again, that could be your main subject with most everything between you and in progressively falling off in clarity as things get clooser to you and conversely things behind it would also fall off as they get farther away but you most always have more clarity behind your subject for any given distance and f/stop used. So you can see you have more control now of what you want to emphasize.

In Bob's very nice shot above you can see that the fence is starting to fall off as it distance to the sensor plane becomes closer which isn't too objectionable as it does tend to lead the viewers eye to the Supply Companies tall weathered Red shed which is in sharp focus. So you can see what Orgnoi1 meant.

The point I forgot to mention last night, actually very early this morning, is that your metering choices, in your Rebel XT are, Evaluative [E], Center Weighted [CW] & Partial [P]. In most circumstances in model phoptography I imagine it better to stay with CW or P if you have specific subjects your trying to call attention to and meter off them. The meter set for E can be infulenced by very light areas in the scene such as the white road in the forground and not allow enough exposure for the darker areas depending on how much area your trying to show if your subject is darker. Likewise in CW if the White road is in part of the central metering circle/rectangle it can also infulence the exposure if your subject is darker.

I prefer Spot [P] and the use of the central metering spot in the camera and sometimes CW to get a bit more averaging but with center weighted reading from the scene.

I hope my explainations are not confusing and it does seem that your making fair progress on your own too.

HTH

David's Digital Photography
 



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