No strobes, DSLR 30mm 1.4, a good beginner lens choice ?

[ronscuba]

I have a Canon T2i and a bunch of lenses. Looking to get a housing and would like to start without strobes and use one lens. To start would a Sigma 30mm 1.4 lens work well ? I was thinking 30mm on a crop sensor camera gives a versatile field of view for a beginner. The 1.4 aperture should be an advantage shooting without strobes.

What do you think ?

 

[Larry C]

Minimum focus distance is about 16", which is a little long, but 30mm would be an OK length for fish portraits, small schools, diver pictures and sections of reef. The 1.4 aperture should allow a decent depth of field at around 5.6 or higher, which combined with shooting at maybe ISO400 would give you decent light for shots at some depth. Probably 1/60 for macro and down to about 1/30 for wide angle. Since it's a prime lens, you don't have to worry about looking for a gear for it as long as it fits in the port. With a 16"minimum focus, you might not be able to use a dome, but flat ports work fine at 30mm with a little narrower field of view.

 

[ronscuba]

This is mainly for my wife. Topside, I usually manually adjust the ISO, shutter speed aperture for her and let her shoot away. For underwater do you recommend she shoot P mode auto, aperture priority or shutter priority ?

 

[Jeevz]

I have this lens. It is a great walkaround prime for a crop camera; as you say 30mm is a good focal length (48mm FoV in full frame equivalent).

If you are meaning to use underwater then it probable would work ok, but there are better options. I presume you already have the sigma 30mm? What other lenses do you have?
With the sigma you would sort of be restricted to taking fish portrait/other 'portrait' type shots. It's not wide enough to use for big fish/animals underwater, and it's max magnification of 0.09x rules out macro shots.

In terms of the f1.4 being an advantage - I am not sure if you will find this to be the case in most instances. The issue is that, unless the water is super clear, even without strobes you will want to get as close to your subject as possible. At 1.4 this will make your depth of field razor thin. For some shots this may be desired however.

At the end of the day you can always buy new lenses and it is great to get out and start shooting so you may as well use it, and when you feel limited then buy something new

Also - I would recommend you get a strobe as soon as you can. It is the piece of equipment that will make the biggest difference to the quality of your photos.

Hope this helps a little

---------- Post added February 6th, 2013 at 12:12 AM ----------

This is mainly for my wife. Topside, I usually manually adjust the ISO, shutter speed aperture for her and let her shoot away. For underwater do you recommend she shoot P mode auto, aperture priority or shutter priority ?

Without strobes I would use AV as long as she is comfortable adjusting aperture and ISO (which is easy to learn)

 

[ronscuba]

I have the following lenses:

Sigma 30mm 1.4
Tokina 11-16mm 2.8
Canon EF-S 17-55mm 2.8
Canon 50mm 1.4
Rokinon 85mm 1.4


I imagine I could use the Tokina for wide angle with a dome. Is zooming UW not used ? If so, could I use my Sigma 30mm for medium shots, Tokina for wide, and then get a macro lens like a 60mm for closeups ?

 

[Larry C]

The Tokina is a great underwater lens for the non fish-eye set. At f2.8, you've got plenty of light and the focus is closer. With the right dome you'll have excellent focus both close and far. With white balance or a filter at shallower depth you should do fine. The 60 is a good choice for close-ups. It allows portraits of small stuff as well as macro. The 11-16 will be best for larger subjects, reef shots with divers, etc. To zoom the Tokina, you'll need a gear for whatever housing you're using with the lens.

 

[ronscuba]

Going to Cozumel for a long weekend in July. Wife not so interested in shooting wide angle. More interested in shooting fish, anenome, lobster, etc.. Since this will be her 1st time shooting UW, want to give her one lens and treat it like a P&S. Should I use my Sigma 30mm, get a 60 macro or get some other lens ?

 

[dhaas]

ronscuba,

Sigma 30mm f1.4 only focuses to 15.7" according to their web site. Meaning if you try and use it behind a DOME port you'll need some type of diopter (+2 or +4?) for it to "see" the apparent image a dome creates maybe 10" - 12" in front of the housed lens. Above water any port is imply a "window" the lens looks through.

I've seen many folks miss this detail. They put a lens that doesn't focus to 12" or closer behind a dome and test it above water. But once below they want to open the damn thing and flood it as it endlessly racks back and forth trying to focus

Behind a flat port it will focus but will also pick up an approximate 1.3X MORE magnification angle due to refraction. (like flat face masks magnifying size and distance)

Good luck and have fun shooting!

David Haas
www.haasimages.com

 

[ronscuba]

Here is something interesting. The Sigma 30mm is 2.3" long. The Canon 60mm macro is 2.7" long. Maybe a single flat port will work for both ? Then a dome for my Tokina 11-16mm in the future for wide ?

Was thinking the 30mm in a flat port would still work for medium size subjects ?

 

[Larry C]

Yes. I use a Nikon 35mm f2.0 occasionally when I want bigger subjects than I can shoot with the 60. The 30 will work for small to medium size schools of fish, portraits of medium to larger fish at about 3ft., portraits of smaller stuff like lobsters and anemones at closest focus (remember, it's 16" from the sensor, not the port). You're not going to get gobies and nudibranchs with that lens. The 60 will be much better for medium to small subjects. You can get as close as you want for the gobies and nudies and back up a little for portraits of fish that are 9-30" in length. You can get a diver shot if it's a front shot of a horizontal diver, but if you back up to fit the whole diver you're too far. The 30 will do those. Figure out priorities and use the appropriate lens. The flat port should work fine for both if it's big enough to hold them, but check the length when close focus is used to make sure it doesn't hit the glass. Get a dome that works with your 11-16 for those reef shots, ship wrecks, sharks, seals, turtles, mantas...