Disappointed with first results from Digital Rebel XT

[jkhansen]

Hi all, I recently switched from a 35mm Rebel to a Digital Rebel XT. In 35mm I was using Velvia film

exclusively, and I take all my shots with a tripod. I do mostly landscape and close-up shots. My first

outing with the DSLR gave me very disappointing results, and I hope you can help me understand some

of the problems I had.

 

1. In all of my shots that included sky, mountains, and vegetation (and sometimes water), there is not

one shot that is properly exposed. I bracketed all of my shots in 1/3 stop increments. Sometimes I

bracketed in both 1/3 and 2/3 stop increments. In the shots where the clouds and snow are properly

exposed, the vegetation is too dark. In shots where the vegetation is properly exposed, the snow and

clouds are blown out. This happened on both fully overcast and partially cloudy days. I used evaluative

metering in all shots and no filters. With my center metered 35mm camera, I would meter off of an area

that I wanted to be medium tone, hold the shutter button halfway down, then recompose and use those

settings for the shot. I had very high success with proper exposures. However, in the DSLR it does not

appear that I have the option of using this method. Some of my DSLR shots were perfectly exposed,

especially when no sky was included, such as a waterfall and a close-up of a flower. Is the dynamic

range of the DSLR smaller than that of Velvia? Should I have used a setting other than evaluative

metering? I picked this method based on what the user's manual says and the conditions for my shots.

Is there a way to force the center weighted settings to be retained when recomposing a shot? I guess I

could switch to Manual mode for this, but geez, what a hassle.

 

2. In some of my shots, including all bracketed shots of the same image, there is a light spot in the

center of the image. It does not look like lens flare because the spot is perfectly round and is exactly in

the middle of the shot. It looks more like the aperture opening. This happened on both fully overcast

and partially cloudy days. Could this be light entering the viewfinder or could there be another

explanation? Like I said before, I use a tripod for all shots, and I tend to compose the shot then step

away from the camera to release the shutter and bracket. I never once had this happen with 35mm.

 

3. All of my shots have less detail than Velvia. Am I just seeing the difference in resolution between

digital and film?

 

Sorry for the long post, and thank you for your comments.

 

Jeanne

[mendonphoto]

JPEGs right out of the Digital Rebel will not look as good as Velvia. In fact, Velvia arguably being the ultimate in image quality (for some types of photography at least), you may not get results as good with your Digital Rebel. I don't think an 8MP camera can match Velvia 50 and the new 100 at least as far as resolution goes.

 

But, you can get them to look very good. The first step is to always shoot in RAW mode. Then, make sure you always "expose to the right". That means get as much exposure as possible without blowing out anything that is important. So, check your histogram. The thirst step is some processing in Photoshop - color & brightness adjustments, sometimes some HDR work, and always some sharpening.

[mendonphoto]

Oh, and i don't know what the light spot could be. Perhaps you could post an image.

[digitmstr]

>>My first outing with the DSLR gave me very disappointing results<<

 

One question: what results did you get the FIRST time you shot with your film SLR? Just curious.

 

Now, onto the post.

 

If you shot JPGs you have to realize that it is the equivalent of an instant Polaroid. Not the BEST for ultimate quality! Instead, shoot RAW and "develop" the pictures in you favorite RAW conversion program. I use and strongly suggest C1 PRO - it's worth the money and in IMO it's best such program today.

[splat]

I think your biggest problem is the reduced dynamic range you have with digital. Sure there are ways around it using RAW and/or multiple exposures but for shots like you describe you are really going to have to work at it to get image quality like you could get with film. Sure manual mode can help you get an optimal exposure to start with but it will still require some post work.

[john_hanlon3]

With regard to your exposure problem, I would suggest using partial or center weighted metering rather than evaluative. Meter for a medium tone, press the AE lock button, recompose, then fully depress the shutter button.

I don't know but maybe the light spot in the center of the image is caused by the lens; you didn't say which lens you were using. Have you noticed the light spot with any other lenses? Of course it could simply be light entering the viewfinder.

I use an XT and it usually gives me sharp, well exposed images, except when I do something wrong! Incidentally, I have never noticed any difference between JPEG Large Fine and RAW image quality when viewing the full size image on my monitor.

[gdanmitchell]

<p>I also use a <a href="http://www.gdanmitchell.com/2006/05/26#a515">350D</a>.

The 350D is working quite well for me, so there must be an

explanation for the problems you are encountering.

 

(I also do a lot of <a href="http://www.photo.net/

photos/danmitchell">landscape</a> <a href="http://www.gdanmitchell.com/

l">photography</a>.)

 

<p>Compared to film, some of what you'll want to do with digital is exactly

counterintuitive. For example, with film you might be willing to slightly overexpose so as

not to lose shadow detail. With digital overexposure is deadly; you'll burn out highlights

completely. Use the blinking highlight indicator on the 350D display after each shot and

reshoot if you are getting blown hightlights. (I always shoot with display set to the mode

that shows the histogram and the small version of the shot.)

 

<p>If you aren't already doing so, shoot in RAW mode. RAW preserves the widest dynamic

range and affords you the most leeway for post-processing adjustments. For example, you

can often recover some shadow detail from a RAW image that would be pretty much gone

in a .jpg. (You still can't get anything back from overexposed - e.g. "blown out" -

highlights.)

 

<p>As was pointed out, the image straight from the camera is rarely going to be the best

possible version. Certain software procedures are pretty much routine for getting the most

from your images. They include:

 

<ul>

<li>Levels adjustments.

<li>Saturation adjustments.

<li>Sharpening adjustments. (There is a lot of info - and misinformation - on this topic,

but best to start reading up on it.)

</ul>

 

<p>You should be able to do the "half press and recompose" bit on the 350D - not sure

what is going on there.

 

<p>Unlike film, with the digital camera's histogram and highlights display you can get

instant feedback on the shot. Check after each shot and make adjustments. For example, I

do find that the 350D (and other dSLRs) will overexpose bright highlights in a scene. This

shows up in the display right away; I delete the first image (2 seconds work), set exposure

compensation to adjust for the error and shoot again.

 

<p>I'm not an expert on Velvia - I stopped shooting film quite awhile ago, and even then I

was largely shooting transparencies - but I understand that digital's dynamic range should

be as good as, and perhaps exceed, most films. However, the response curve is said to be

different. And keep in mind that digital acts more like transparency film that negative film.

 

<p>I rarely bracket in 1/3 stop increments - unless I'm in "very careful mode," in which

case I'm also probably using a tripod and manual settings. You might try bracketing in full

stops, at least at first.

 

<p>Point #2 is strange. Could you post an example of the light spot? That shouldn't be

happening. There is an outside chance that this could be a dust spot on the sensor, but a

photo should help make that diagnosis.

 

<p>Again, I'm no Velvia expert, but most people (with some disagreement) are of the

opinion that 8 MP digital cameras at least equal the resolution of 35mm film. It may take

sharpening in Photoshop to make this visible though. (Or you could have a focusing issue

with your camera and/or lens. Again, posting an example would help here.) I have posted

some <a href="http://www.gdanmitchell.com/2006/01/28#a292">100% crops</a> of

some photos taken on my 350D with the EF 17-40mm f/4 and sharpened in photoshop -

take a look and see if they compare to what you are seeing with your equipment.

 

<p>Good luck sorting all of this out!

 

<p> - Dan

[gluteal cleft]

"I think your biggest problem is the reduced dynamic range you have with digital."

 

Actually, I would guess the opposite, since Velvia has a smaller dynamic range than her new Rebel.

 

Several points for Jeane:

 

1. If you let the camera make the metering decisions for you, then you can't complain if the exposure isn't what you wanted. Make the decisions yourself. And shoot in RAW, which will give you a much greater ability to adjust the exposure after the fact (should you still need to) than you get with JPGs.

 

2. If you're used to Velvia, you're not going to get a similar look straight out of the camera. Open up a shot in Photoshop, open up levels, and drag the shadow slider to the right, and see if that's at least a first step in getting the saturation and contrast that you're used to.

 

3. For detail, the rules for capturing a sharp image are just the same as with film. When I do my part to get a sharp image from my RebXT, it has never failed to disappoint. There may be some difference between Velvia and the RebXT, but the XT can still produce a very sharp, defined, detail-filled image if you (and the lens) do your part.

 

4. The spot in the middle of the camera - that certainly shouldn't be there. Post an example.

 

steve

[michael j hoffman]

Welcome to the world of digital. If you still have your film camera(s) then you have to let each technology find its place in your photographing. I have a Canon EOS 10D. There are some things the 10D does very well - time sensitive projects, high ISO shooting and, when desirable, instant feedback, et al. For everything else I use my EOS 1N or one of my Leica rangefinders.

 

Digital may not fit your photographic applications very well. But you also cannot expect to learn the nuances of digital photography intuitively. You didn't "meter off of an area that I wanted to be medium tone, hold the shutter button halfway down, then recompose and use those settings for the shot." on the first frame of the first roll of film you shot with your film Rebel. What makes you think you should be able to do it that way with a DSLR? The feedback is instant; the learning curve still takes time. There are more things I am willing to photograph with my 10D now then there were the first few weeks after I bought it three years ago, and there are still things I prefer to shoot on film. Find out where it is that you are, then adjust your equipment and/or your approach accordingly.

 

Michael J Hoffman

[brucecyr]

First: I'm not competent to address all your problems, but the other folks who have commented seem to know their business!

 

You seem to be right about the relative resolution of Velvia vs. the 350D's 8mp sensor. This guy calculates Velvia is equivalent to about 22mp:

 

http://www.vrphotography.com/data/pages/askexperts/pano/filmvdigpanos.html

 

The light spot in the center of your images sounds like defective gear to me. I would contact Canon for further guidance.

 

Bruce

[r.sriram]

Your best bet would be to shoot raw and post process. You can save a lot of highlight and shadow detail that way, compared to shooting JPEGs.

[tommyyearginjr]

RAW format will give you total control over adjusting the image to suit you.

The software Canon provides with the camera (I use the Mac version, which is just like the PC

version) is excellent. It does a great job with editing images, particularly RAW images.

As far as unwanted light, I use a lens hood, which is very useful in bright locations. Being

able to view the image as soon as it is shot is a plus, considering that using a lens hood can

cause some vignetting to occur.

[jkhansen]

Thank you everybody for the info. I guess I didn't realize how different it would be

shooting digital. Silly me. To answer a previous question about my lenses, I have all Canon

EF lenses. The lens used when the light spot appears was a 75-300 Ultrasonic zoom. An

example of the light spot is hopefully included in this post if I did it correctly. As you can

see, it was a completely overcast day with no direct light from any

direction. The light spot occurred in 7 out of 62 shots. Any insight on this issue is

appreciated!

 

Jeanne

[dogbert]

I nearly always shoot JPEG with a 350D and generally find the on-screen results superior (but different) to velvia, which I also shoot often enough. Though nothing compares to the look of chromes through a loupe.

 

As for metering problems, with digital the histogram should be your main metering tool. That is digital gives you and instant readout of what you exposure is, and if the camera has metered incorrectetly just use exposure comepnsation and shoot again.

 

What parameter setting did you use? On a contrasty day, I tend to turn down the contrast parameter to zero. Genrally I shoot with saturation at +1 or +2 to get a saturated look.

 

Not sure what the spot is, but it doesn't sound normal.

[jkhansen]

Well that upload looks like crap! I don't know what to do different to stay within the

posting limits of 100k and 510 pixels wide. You can still see the problem even with this

pixellated, low res image, so hopefully you can get an idea of the problem.

 

Jeanne

[silvergull]

Jeanne: Take some time and read http://www.kenrockwell.com/ Ken will save you much grief

and time.

 

Cheers,

 

Jim

[rainer_t]

Jeanne,

 

I just looked into the EXIF of you uploaded image ... f/25 ...

with that f-stop (and the spot appearing on some images and not on others) my guess is ... sensordust ...

 

So, introduce yourself to cleaning procedures.

 

Rainer

[mendonphoto]

Could be sensor dust, but it looks a little big to me for that. It looks more lik a drop of water or a fleck of something on the lens - either front or back element. Is that possible?

 

If you're saying that you used the Canon 75-300mm USM lens to take the picture, then digital vs. film quality is the least of your worries. That lens is going to be the limiting factor. Same for you other lenses if they are in the same quality class.

 

That image you posted, if shot in RAW, would have been totally salvagable - especially if you reduced exposure by another 1/2 stop. I can see that there is still some detail in the sky, but it was lost in the jpeg conversion.

 

And, you should really try to avoid f/32 and even f/22 if at all possible with your Digital Rebel. Remember that the sensor is smaller than a frame of 35mm film, so you get increased depth of field, but softness at small apertures due to dispersion is also increased. Of course, f/5.6 - f/11 are best, f/14 - f/16 is okay, smaller than that and you really take a hit on sharpness.

[beepy]

Yeah, I'm in the sensor dust camp.

<p>

Or the sensor smudge camp. Read the article on photo.net on

<a href="http://www.photo.net/equipment/digital/sensorcleaning/">sensor

cleaning</a>. Open your manual and learn how to put your camera in sensor cleaning

mode and pop that mirror up and inspect your sensor under a good light and see what

you have.

<p>

Also, check out

<a href="http://www.visibledust.com/">Visible Dust products</a>.

<p>

To minimize dust in landscape photography (especially - outdoors, wind, sand eek!) I

really try to minimize lens changes - and when I do it, I do it quickly. Maybe I'm

superstitious.

[danny_lee2]

that is a weird dot, I used digital rebels for years for more than hundred thousand exposures, never saw a dot like that.

[dogbert]

Doesn't look like dust to me. Every dust spot I have ever seen is dark grey or blackish looking.

[brent andersen]

That looks like flare to me, although it's hard to see - doesn't look like dust. I would be shooting that image at about f/8 -f/11. It's going to be a tough image to expose given the light sky and the water, and the dark mountains. Limited dynamic range is a problem with digital. Using a graduated ND filter should help.

[gdanmitchell]

<p>The dot has the greenish cast that I usually see in lens flare on my Canon, so I lean

towards this being flare. </p>

 

<p>However, as several people pointed out, shooting at very small apertures (someone

said this was f/25) will almost always reveal dust on the sensor. In addition, such small

apertures reduce the maximum sharpness of the image - while you'll have greater depth

of field, the most in-focus portions of the image will be less sharp than if you had shot at

a larger aperture.</p>

 

<p>In general, many of the Canon lenses are sharpest around f/8 with crop sensor

cameras such as the 350D, give or take a stop.

That particular image probably would have looked better at f/8.</p>

 

<p>The shot is really out of focus and has very low contrast as well, and perhaps a bit

overexposed. (But you knew that - this is why you posted your questions! :-)</p>

 

<p>Assuming a decent exposure in RAW mode (really far better than .jpg in virtually all

circumstances) here is the outline of a workflow that might be a starting point for

optimizing your images. I use Photoshop, but you can do much of this with other tools

such as the Canon software or the Adobe Lightroom beta:</p>

 

<p>1. Browse images in Adobe Bridge (part of the Photoshop package).

 

<p>2. Double-click an interesting image to open it in the Adobe RAW converter.

 

<p>3. You <i>could</i> let the RAW converter do an automated set of adjustments, but

to

do it manually try the following:</p>

 

<ul>

<li>Check the <i>preview</i>, <i>shadows</i>, and <i>highlights</i> checkboxes

above the image ,and uncheck the four <i>auto</i> checkboxes on the right.</li>

<li>While watching the histogram adjust <i>brightness</i> so that the brightest portions

of the image are just below the maximum level. (Watch the image for colored - red - areas

that indicate blown out highlights.)</li>

<li>Adjust the <i>shadows</i> slider so that the lower end of the histogram curve ends

near the right left side of the display.</li>

<li>If the histogram is skewed wildly to the right or left, you <i>may</i> want to adjust

<i>brightness</i> to some extent to compensate.</li>

<li>You will probably want to raise <i>contrast</i> a bit - perhaps start with a setting in

the 30-35 range.</li>

<li>It may also be worthwhile to increase <i>saturation</i> to something in the 10-15

range, though you can do this later in Photoshop as well.</li>

<li>Click the <i>Open</i> button to open the image for editing in Photoshop.</li>

</ul>

 

<p>4. The image may look pretty decent at this point, but there is much more you can do

here if you choose. I won't go into the whole business of working in layers here - either

you already know about this, or the explanation is going to be too long for this space.

Typically, you'll likely want to at least do some additional levels adjustments, along

with perhaps some work with saturation, etc.</p>

 

<p>5. Save your main copy of the file as .psd or some other non-compressed non-lossy

format.</p>

 

<p>6. I recommend saving the file unsharpened and sharpening before printing or

converting .jpg for the web. There are tons of methods out there for sharpening, and a

million tweaks of each of those methods. Here is a starting point that may work OK:</p>

 

<ul>

<li>Display the image at 100% magnification.</li>

<li>Select Filter->Sharpen->Smart Sharpen. In the Sharpen panel, try something like

Amount:150 and Radius:.8 as a starting point. (Other's will no doubt have valid alternative

ideas here.) Apply the sharpening.</li>

<li>Display the image at 25% magnification or so - you want to see the whole thing on the

screen.</li>

<li>Select Filter->Sharpen->Unsharp Mask. Here try settings along the lines of 12-20,

50, 0 as a starting point.</li>

<li>Resize as necessary for printing or display using Image->Image Size.</li>

<li>Again choose Filter->Sharpen->Unsharp Mask, this time with settings like

25-45,1,1.</li>

</ul>

 

<p>7. For posting on the net, you'll want to "Save for the web" - though there are

alternate

methods here as well. (Be careful not to save over your .psd file!)</p>

</p>

 

<p>(Disclaimer: There are other ways to do all of this, this is a generic description, I've

simplified portions of this, and other photographers might approach it differently.)</p>

 

<p>This all probably sounds like a huge pain to one who is comfortable with film, but

once you get into this process I think you'll really enjoy the control it gives you and the

fine image quality that can be the result.</p>

 

<p>Good luck! (and apologies for the long post.)</p>

 

<p>Dan</p>

[gdanmitchell]

<p>Above, I careless wrote:

 

<blockquote> Adjust the shadows slider so that the lower end of the histogram curve

ends near the right left side of the display.</blockquote>

 

<p>Talk about being inscrutable! The "right left" side of the display?

 

<p>It should refer to the <strike>right</strike> <b>left</b> side of the histogram.

 

<p>Dan

[digitmstr]

The spot is definitely FLARE.