Alright my first post, yes!

After a few years of a P&S camera, at least for underwater, I am stepping up to finally use my 5D when I go diving. I have used DSLR for many years, at least over the last four, above the surface but find myself in fish-out-of-water sense; in that I am realizing not many of the people I dive with or shoot with in other capacities know much about the other side of photography. I just have not been exposed enough to a side of photography I truly enjoy to know. Most note basics, but none can really answer other questions. So I figured since this is the vanguard of underwater imaging why not post a Q that has irked me, with that ask and without much further ado here it is are:

Are fixed focal lengths or zooms preferred? If the latter; other than presetting the focal length pre-dive is this capability, changing lengths that is, able to be used while diving? Because quite honestly, I am tired of losing picture quality to digital zoom on subjects that tend to be camera shy - that is my main reason to use the 5D over P&S.

An easy answer for most, I’m sure but not for me. I plan to use an Ikelite 5D housing with the 8” dome.

So, let me have it.

Later.

e=me

Yes, you can normally zoom a zoom lens in an underwater housing provided the housing and/or port are set up for it. In general, primes are considered to have better image quality but there are a number of good zoom lenses and a lot of people use them underwater. Depending on the lens, you may need to use a diopter on the zoom lens behind the dome. You retailer or Ikelite should be able to guide you on that one. It is quite the quantum leap from point and shoot to 5D . . .

Mike

MikeO.

Thank you...finally a straight answer.

Yes...P&S to 5D is a jump but I have been using the 5D for near a year long with a 30D back-up. So I am familiar with the functions above surface....I just have never been frustrated enough to get a set-up to take them under, but the time has come for me to make the change.

Thank you again for this mundane information.

e=me

You will be using a fixed focal length lens for macro (I would recomend the Canon 100mm USM) and for ultra wide angle (canon or sigma 15mm macro) because there are not zoom alternatives.

The place where you might use a zoom(underwater) would be a 17-40 for a less wide Wide Angle. Zooms are more convienant, but primes tend give you better image quality. The choice is really up to you. I am a prime guy myself but most people prefer zooms.


Yes, you can change the focal length of most zoom lenses underwater. BUT Zooming in is not a solution for subjects that are camera shy. If the subject is not close the picture will not come out good. You've got to just learn how to make them to smile and say cheese, or else find a new subject. You use the zoom to get a different perspective.

I'm far from being the expert on DSLR, but since you have 4 yrs of experience using a DSLR topside, let me ask you a question that might help answering your question... What do you find sharper, shooting with your prime (fixed focus) lenses or zoom lenses?

I think the consensus is the prime lenses will always be the better especially at the widest apertures. However, as you might know, there are some quality zoom lenses out there that can compete with expensive primes lenses when stepped down. Which is another key point. Underwater, you will rarely be shooting at say f/2.8. Probably closer to f/8 or higher.

Most u/w DSLR housing/ ports will have a zoom collar so you can adjust the lens zoom. But there is a problem if you have a macro port on and you're tryin to zoom out to 18mm wide angle! And vice versa when you zoom in behind a dome port.

With that, I'll let the experts step in...

Hello E and welcome to Wetpixel,

It seems that you have a lot of research to do before your purchase - and you've come to the right place. Hopefully I can help answer your questions too.

Firstly, yes, zooms are very popular underwater. This is because when shooting underwater you really have to be within 4' of your subject in order to get any light onto it from your flashes. So you can't "zoom with your feet" like you can above water, so you use a zoom lens to change your composition and perspective.

Secondly, there is no such thing as digital zoom on a DSLR so don't worry about that.

Thirdly, you use a zoom lens underwater by putting a gear onto the zoom ring on the lens. There is usually a knob on the housing that engages the zoom ring and lets you turn it underwater. Some macro lenses have manual focus rings which work in the same way.

You said you plan to use the 5D + Ikelite housing + 8" dome which seems like a good start. Some lenses which work well with that setup are the Canon or Sigma 15mm fisheye, the Canon 17-40L and the Canon 24mm (f2.8 or f1.4L)

Cheers
James Wiseman

I use a Nikon DSLR but the principles are much the same. While you do get much better image quality with a prime lens, I tend to use a zoom (18-55mm) most often because of the great flexibility of subjects. As James suggests, you need to get as close to the subject as possible and a zoom lets you get close to both large subjects and small ones.

I have a 60mm macro lens which I use from time to time but often get frustrated missing out on subjects because I would be too far away to get them in. Even things as small as a weedy seadragon or a lionfish is too large for the 60mm - unless you just want a head shot.

I recommend you start with a zoom like the 17-40L that James suggests and then see what subjects you prefer.