still having trouble with exposure, and another ?

[Saltysteele]

okay, first, i'm still having trouble with my exposure. check out the pic of my chalice, then see below

notice how washed out the top part of the picture is? how on earth do i stop this from happening? it's driving me flipping nuts, not to be able to get the true colors of the corals, because they turn out too bright.


also, poseidon can catch this one, how do i set my 20D up to shoot to where it does bracketing? i thought i had it set up to shoot 1 stop up and 1 stop down, but it only takes the one pic.

finally, i've noticed my pic's end up looking grainy, and not as defined as some of you guys' pics, even when shooting at 200 iso. how do you guys get your pic's so smooth?


i'm just getting frustrated at not being able to take nice pic's :squigglemouth:

 

[returnofsid]

At ISO 200, you're still getting grainy pics? Or, is the graininess a result of enlarging the photo? What setting do you have set, as far as what memory level to take and save pics at? I do see what you're saying about the upper portion of your photo being blown out, slightly. I would try a smaller aperture (higher Fstop) and, if needed, a longer shutter speed. Noise at ISO200 is really strange though. Also, have you custom white balanced to your tank recently? Keep in mind that white balance will shift as bulbs age, so should be customized on a regular basis.

I keep having to edit because I think of other things...lol. You should have an AE Lock feature, atleast I do on the Rebel Xt. Try focusing on the brightest part of the coral, locking AE and then shifting your focus down to a darker area of the coral. See what results you get that way.

 

[Poseidon]

The first thing that I see is the HUGE boulder on your sensor!

Next, what you are dealing with is a dynamic range issue, meaning the difference in light that falls on your BRIGHTEST object, versus the amount of light that reaches your darkest part. If that difference is to great, then you will always have an area of overexposure, or an area of underexposure.

As for bracketing, I do it manually, so I can't help you off the top of my head. (The wife uses the 20D, I haven't shot with that one in a while.)

Grain can come from underexposure as well, especially in the shadow areas. Photography is an art, and is all about working the light to suit your vision, time, practice, and a creative flair are all required for you to succeed. Sometimes the location of a coral for it to grow, is not the same as the requirements for it to photograph well.

 

[Saltysteele]

Thanks, guys! I'll try some more shots tonight.

The first thing that I see is the HUGE boulder on your sensor! ...................................Sometimes the location of a coral for it to grow, is not the same as the requirements for it to photograph well.

actually, it's not my sensor, mike. it's in my lens. the tamron is going back, and i'm getting the canon.

also, your comment on location for growth and photo possibly being different, struck a note. it's dinging in my head :tongue:

 

[JuniorMC8704]

corals make challenging subjects.

Here is my observation.

Even with intensely bright lighting, you still have an issue.

Generally corals are brighter in terms of color and intensity on the areas exposed to brighter light, and darker colors in the less lit areas.

So you have the already brighter colors getting belted with light, and the darker colors getting far less.

This makes is hard because the brighter colors are going to almost always be over exposed to properly expose the darker areas.

This is certainly a hard problem to solve.

Ive been giving this a LOT of thought recently.

My thought is to filter the flash with a blue filter. The goal would be to emit a flash that is the same color spectrum as the tank lights.

This would allow you illuminate the darker areas, eliminating the shadows.

This would give the whole coral an even amount of light, and in theory, allow for far better, more even exposure.

Im going to contact Dr. Marzel at night sea and see if he can make me a filter for my hot shoe flash.

Ill keep you all updated.

 

[Poseidon]

WOW! That chunk is in the lens? It looks a lot like sensor dust to me though, but it must not show up with your other lenses?

Glad I could help!

 

[Saltysteele]

thanks, jr. will be interesting to see how it pans out

mike, yeah, it's in the lens. you can see it with the naked eye. i've cleaned both ends of the lens, nothing there. it actually appears to be about in the middle of the lens, but i tried cleaning it, just to be sure.

amazon has been awesome, and a pleasure to deal with (i was worried they'd give a hassle)

 

[cparka23]

If you do a search on HDR (high dynamic range) photography and tonal mapping, you should come across a lot of information on this subject. As far as software goes, Photomatix is pretty good and is also available as a plug-in for Photoshop.

Trouble is that it's limited in usefulness for general photography. The better bet is to plan the lighting before shooting the subject, which is easier said than done w/ some aquariums.

Photoshop CS3 has an HDR function where differently exposed pictures are combined into one huge 32-bit photo. I don't particularly like the result since it does little more than allow you to move exposure sliders with greater control than before. You can use exposure adjustment layers to finesse the result, but it's not a semi-automated task like the tonal mappers will yield.

 

[Saltysteele]

thanks for the info, bro!

honestly, despite how obvious it seems, i hadn't even contemplated this thought, until you guys mentioned it. i mean, it only makes sense. i've gone back to shooting in manual mode (i like the extra control) from AV mode. so, it would seem like as i was metering and the whole bit, i would have thought about how one portion is really bright and another is dark and shadowed.

once again, i've had a you-dips*** moment :haha:

I was going to take some pic's, now that i'm home from work. however, my goby must be pretty hungry. he's stirring the crap out of the sand (literally), and now the water is full of particles. i'll go feed the crew and wait till it clears up.

once again, thanks to everyone's help. short of taking a photo class (which i had contemplated), i would have never figured out how to take nice pics (not saying i'm there yet, though).

thanks, guys! i know it can get pretty bothersome answering the same questions by different people everytime you turn around. i truly appreciate your time and interest in helping others!

 

[cparka23]

One more thing to add. Sorry if the horse is beaten to a pulp. LoL

I just remembered that TWiP (This Week in Photography) did a video Podcast on HDR photos and the ways to compile them. Here's the link to open it in iTunes, and show notes can be found here.

I can see this being something that could work for Junior or Bret, but every technique has limits to its usefulness. It just depends on the application. Still, it's pretty enjoyable to watch, can be used outside of reef photography, and this is easily the best episode of the whole podcast series.

And I realize that I've been posting a few links to different tutorials, here and there. Any of them are helpful, kindly let me know. Otherwise, I'll take a hint that it's too much.

 

[Mr.Firemouth]

It looks over exposed, I played with levels and saturation to get rid fo the white blowouts....

PS can only go so far before it doesn't look realistic though.
Light is my issue with fish pics. They are all too dark. I need a bigger external flash unit.

In my camera I adjust the metering levels to -1 to avoid the white look and take pics with auto white balance and the with 9900K and see how different they look. One pic may take 15 shots at different settings. I am still really new to all of this and it gets frustrating. Especially when my brother-in-laws camera is a cheap P&S that takes great fish pics!

 

[gparr]

Poseidon is right, you're dealing with a range of light that is beyond what your sensor can capture without over or under exposing some part of the image. My general practice is to use the camera's meter reading (it's probably wrong) as your starting point. Then shoot a bracket of one stop over exposed, one at the meter reading, and one stop underexposed. In this case, the most usable shot will likely be the one-stop underexposed image because it will be the one that retains detail in the highlights. If you have to make a choice, keep details in the highlights and let the shadows show noise. Blown-out highlights ruin any image. Noisy shadows can be fixed with noise-reduction software, or, if they're dark enough, won't matter.

Take that image (I assume it's a RAW file) that is one stop underexposed and do whatever processing you do on the image. Use shadow/highlights to open up the shadows and bring down the brightness of your highlights. Your current exposure isn't that far off. One stop underexposed should do it.

I have had extreme instances where two stops underexposed, according to the meter reading, turns the trick. In particularly difficult situations I've had good success using a graduated neutral-density filter. I use the Cokin system so I can slide the ND filter up and down. It takes a little fiddling, but works well.

As for automating the bracketing with the 20D, I'm no help either. I shoot manual and find it just as easy to turn the shutter-speed wheel. Most of that automated stuff seems to be much more hassle than it's worth.

Gary

 

[gparr]

It looks over exposed, I played with levels and saturation to get rid fo the white blowouts...
In my camera I adjust the metering levels to -1 to avoid the white look and take pics with auto white balance and the with 9900K and see how different they look. One pic may take 15 shots at different settings. I am still really new to all of this and it gets frustrating. Especially when my brother-in-laws camera is a cheap P&S that takes great fish pics!

Rich,
Your adjustments still leave too many blown out areas. Blown out is blown out, i.e., no data. The image needs to be re-shot to retain detail in the highlighted areas.

If you shoot in RAW and adjust your color temp and tint in the RAW converter, you shouldn't need more that the three-shot bracket I showed you for any shot. A three-shot bracket (one stop overexposed according to the meter reading, one at the meter reading, and one underexposed by one stop) will almost always guarantee one shot that will give you a good image. It's just data, delete the ones you don't want. To me, this approach is faster than spending a lot of time metering areas in a scene to determine the best exposure, which is tough to do with the lighting in aquariums. You can simply compose the shot, get your three images, and move on.

Gary