Beginner Question - Manual with Auto ISO

[Premo83]

Hi all

So far I was mainly doing underwater video and on occasion I was taking picture with ambient light or video lights. Topside I take plenty of pictures of wildlife. Now I want primarily taking stills underwater as well and it will the first time using strobes. I'm getting two Inon Z-330 Type 2 in the next few days to pair them with my Sony A1 and the 16-35 GM lens. Topside I shoot manual with Auto-ISO and then using exposure compensation if I'm not happy with the exposure. This may be a stupid question but does that shooting style also work with strobes or will everything be overexposed as the camera meters without flash? I plan to go manual with the strobes and not using TTL.

 

[Barmaglot]

Without TTL, you need to use manual ISO. It's not that complicated, really. I shoot an A6300 with Retra Pros, and when I'm on wide angle, I eyeball the local conditions after splashing down and reaching target depth, then set up a baseline - ISO 100 if it's bright and clear, ISO 400 or higher if it's a bit dim (early morning or sunset dive), f/8-f/11, 1/60-1/125 shutter speed, half to quarter power on the strobes, then find a spot and take a test shot. If the foreground is blown, I reduce strobe power, if the water is too dark, I reduce shutter speed or open the aperture a bit, or increase ISO. With a bit of practice, I get my baseline either on the first shot, or within two or three. Once the baseline is established, I swim around looking for opportunities, and eyeballing the distance, I adjust strobe power up or down. If I need to take a specialty shot, like a sunball, then I go to the appropriate settings (such as 1/160, f/22, ISO 100, or something around 1/1000 f/11 and HSS) then go back to 'normal' settings for that dive.

For macro, the process is similar, but I generally use 1/160s shutter speed and f/16-f/22 aperture range. Same as for wide angle, I take a few test shots at the beginning of the dive, then adjust as needed. If I want to shoot shallow depth of field, like for example separating an ornate ghost pipefish from its background, then I dial the strobes down to minimum and sometimes use HSS as well.

With an A1, you have access to a wider range of strobe sync speeds, up to 1/400s or 1/500s in crop mode, but unless you have the M82 Sea & Sea internal correction lens, you will likely need to stop down to around f/13-f/16 for sharper corners. Your ISO dual gain kicks in at 500, so that's probably the value that you want to use for darker ambient conditions, rather than my 400.

 

[Premo83]

Without TTL, you need to use manual ISO. It's not that complicated, really. I shoot an A6300 with Retra Pros, and when I'm on wide angle, I eyeball the local conditions after splashing down and reaching target depth, then set up a baseline - ISO 100 if it's bright and clear, ISO 400 or higher if it's a bit dim (early morning or sunset dive), f/8-f/11, 1/60-1/125 shutter speed, half to quarter power on the strobes, then find a spot and take a test shot. If the foreground is blown, I reduce strobe power, if the water is too dark, I reduce shutter speed or open the aperture a bit, or increase ISO. With a bit of practice, I get my baseline either on the first shot, or within two or three. Once the baseline is established, I swim around looking for opportunities, and eyeballing the distance, I adjust strobe power up or down. If I need to take a specialty shot, like a sunball, then I go to the appropriate settings (such as 1/160, f/22, ISO 100, or something around 1/1000 f/11 and HSS) then go back to 'normal' settings for that dive.

For macro, the process is similar, but I generally use 1/160s shutter speed and f/16-f/22 aperture range. Same as for wide angle, I take a few test shots at the beginning of the dive, then adjust as needed. If I want to shoot shallow depth of field, like for example separating an ornate ghost pipefish from its background, then I dial the strobes down to minimum and sometimes use HSS as well.

With an A1, you have access to a wider range of strobe sync speeds, up to 1/400s or 1/500s in crop mode, but unless you have the M82 Sea & Sea internal correction lens, you will likely need to stop down to around f/13-f/16 for sharper corners. Your ISO dual gain kicks in at 500, so that's probably the value that you want to use for darker ambient conditions, rather than my 400.

Thank you, that is the answer I was looking for plus some more valuable tips. Thanks a lot.