New tank causing bad sharpness in photos

[reefmusic]

I didn't know this could happen, but a new self contained tank I set up is causing problems with sharpness when photographing something deeper in the tank. Also some chramtic aberration. It's OK when up close. I have photographed stuff in aquariums quite a bit, but this new one is causing me problems. The tank has curved glass front corners, and I am wondering if the bending process has had a bad effect on the glass overall, photograhy wise I mean.

Anyone ever struck this?

Close up to the glass example

Mid-tank back from glass

The tank is from Aqua One

 

[OldReefGuy]

Are you using auto or manual focus? Auto might be picking up the imperfection on when the glass was bent...?

 

[griss]

I’m a terrible photographer. Sorry, I can’t help but maybe @Misled has some ideas.

 

[OldReefGuy]

flat focal point.....those are the words I was looking for. Try getting the lens as close to the glass as you can.....that might help a bit

 

[reefmusic]

Are you using auto or manual focus? Auto might be picking up the imperfection on when the glass was bent...?

I have tried both. I am taking the photograph through the flat front section of the glass, not the bent corner, but maybe the type of glass they needed to use to enable the bending is just optically poor.

 

[Misled]

Most likely the glass. If there’s any bending to it it creates a lot of problems. As said try to stay as close to the glass as possible and and keep the camera perpendicular to the glass. Make sure your pumps are off and your glass is clean.
questions
Do you use a tripod?
What kind of camera?
What lens?
Do you use a shutter release?

 

[reefmusic]

Most likely the glass. If there’s any bending to it it creates a lot of problems. As said try to stay as close to the glass as possible and and keep the camera perpendicular to the glass. Make sure your pumps are off and your glass is clean.
questions
Do you use a tripod?
What kind of camera?
What lens?
Do you use a shutter release?

I can drag the tripod out, but in the past, handheld has been sufficient. Certainly, with the subject close-up to the front, things are perfectly normal.

It's a Canon 80D with the Canon 60mm macro lens.

No I don't use shutter release.

Another good example when the subject is up against the glass, handheld.

 

[Misled]

A couple things you can try, First what's your aperature set at? Try going to 9-11. Second, let the fish go a bit further fromthe glass, but keep the lens close. I also use off camera flashes above the tank. You can use the on camera flash as long as the the lens is close to the glass.

 

[reefmusic]

First what's your aperature set at? Try going to 9-11

Yes, that will increase depth of field (at the expense oflight levels and hence needing longer shutter speeds), and I have tried that, but it's the clarity within the 'in-focus' part of the image that is still not right.

I also use off camera flashes above the tank. You can use the on camera flash as long as the the lens is close to the glass.

I have done both. These images however, are without flash.

With the lens right up against the glass, the image quality for something more than , say, 75mm away, is unacceptable. For something right up near the glass, and the camera anywhere I want, the image is good.

The only thing left that I need to experiment with, is how parallel to the glass the lens is when I take the shot, and whether it is better with flash or not.

 

[Misled]

It sounds to me the camera may be metering off the glass, The eye in that pic is close.

 

[Misled]

Also if you use a flash, you can increase the DOF without needing a longer shutter.

 

[reefmusic]

It sounds to me the camera may be metering off the glass, The eye in that pic is close.

Nah, I tried manual focus as well, on the things further back. Doesn't improve it.

 

[Misled]

Sounds more and more it's the glass.