Just a couple of questions

[Tinpanva]

Just picked up a Canon 100mm 2.8 lens yesterday for my T3i. In the little time I had to play with it last night, seems pretty nice, I did notice it didn't focus crystal clear at its minimum focal length. Are folks using a magnification lens with this one to get in super tight? Some of the photos I looked at today showed these guys using an ISO of 2000, I'm not sure I've ever taken mine out past 400 except a few times and those were at 800. Are you really able to go to 2000 and not be grainy? I'll give it a try this weekend. On average, what do you think the percentage is of folks using image (focus) stacking on these great coral shots? Oh, I usually have it in MF, but theres a selector switch in addition to MF/AF, what's that usually set on for reef shots?
To be honest, if there's a person out there using the same camera, lens, PSE 11, & willing to share some knowledge, I could sure use it. I took several years of commercial photography back in the day so your not starting from square one. I have the WB lens cover, several WB cards, a decent working knowledge of PSE but I still struggle shooting under my AI Vega LEDs.
I'm shooting a 29 gal BC, front is ever so slightly rounded. I wonder if this is whats giving me trouble in the vivid sharp images.
It looks to be a rainy weekend here in VA, going to give this guy a good workout over the weekend but would be nice to have some pointers. I'll post up some pictures so we have a starting point. Just go easy on me.

 

[IslandCrow]

Any curvature in the glass can potentially give you issues, especially if you're shooting soemthing towards the back of the tank or shooting through the glass at an angle (i.e. not perpendicular). As far as not focusing at the minimum distance, how are you judging that minimum distance? And do you mean focal distance vs. focal length? I'm making that assumption, since you only have one focal length (i.e. 100mm) with that lens. Either way, I wouldn't use one of those magnification lenses. You tend to sacrifice too much image quality. If you really need to get closer, I'd look into extension tubes. Otherwise, I'd just move back a bit. Also, there should be a switch on the lens with two distances. Make sure it's switched on the smaller of the two.

As for ISO, it really depends on the camera, your post processing skill, and your processing software. With my 5DMII, the noise associated with 2000 ISO is very manageable and depending on image display size, nearly unnoticable with a little bit of noise reduction applied in post processing. For my 40D, over 1600 (which is the max native ISO) is nearly unusable. I don't have any experience with the T3i, so I'm not sure how well it performs at that ISO. It also depends on the subject, though. Noise is far less noticable with certain corals and fish. In general, and you probably already know this, shoot at the lowest ISO you can for your lighting conditions and your subject. If that's a grainy 2000 ISO photo, then it's still better than a blurry 800 ISO photo.

 

[Tinpanva]

Well as promised here are a few to give you an idea. The first one came out pretty good, couldn't get it sharper.

These next few are all about the same, just out of focus. I can get the specifics but I think most were shot in the f8-9 range for better DOF but sharpness still sucks.

 

[Tinpanva]

I would like to get in tighter on the polyps but just cant get the focus right.

 

[noy]

get an extension tube set - you will be able get in much closer.

this is what I have - they are great!

http://www.amazon.ca/Polaroid-Focus...2051&sr=8-1&keywords=polaroid+extension+tubes

 

[Tinpanva]

Wouldn't that just make the DOF even narrower? Got some examples?

 

[noy]

sorry - just responding to your question regarding getting closer. Yes it does make the depth of field more shallow. The tubes give you a very close macro shot.

some of your shots are backlit - you won't get any decent detail because under-exposure of the coral (1,2).

with a digital camera - the higher ISO doesn't make the shot "grainy" like a film camera but you get noise/distortion of the colors - you do lose sharpness to the distortion. can you post your exposure settings with your shots? You should get sharp shots with 400 ISO - not sure if its a camera shake, bad focusing issue.