Nightski

This drives me crazy every year, but this year we've had a little surprise. We started in November with -15F temperatures. The ice quickly thickened. I've seen 18" blocks cut out for spear fishing. But now the gulf stream has decided to grace us with it's presence, and for the last week we've been pretty steady between 28-31F ... right below the freezing mark. But the ice is getting dark like it does before it goes in, in the spring. I'm sure the fish, weeds and pollution heat the lake to some degree, so it's really better to be about 15-20F or below. In my opinion. I am hoping the owner of this house stays off the lake today. I actually saw somebody driving a truck on the big lake this morning. There are about 50 houses out there right now. I couldn't believe it ... I could barely look as I went by .. afraid that he'd go through at any moment.

Canon 6D
Canon 100mm F2.8L IS
Manfrotto Tripod

ISO 100
F/22
.4 second exposure

I did have one at F/16 but those foreground rocks were blurry. I'm set up under the bridge in a pile of rocks in the rapids that flow through there.

R.G. Loc: Scotland

Maybe f/16 would have been OK if you'd got the hyperfocal distance right. Those rocks are what - 15ft away? You should have been able to get them sharp by focusing at the correct distance for the hyperfocal effect to kick in. Then again, 100mm is a fair focal length, so maybe it would have been tight getting sufficient DOF.

Where the hyperfocal effect is concerned, one of the things that I found difficult to come to terms with was just how close the focus point needs to be, especially if your foreground objects are close to the camera. You look at the far field and think that there's stuff there that needs to be sharp, so you tend to keep the focus point a fair distance from the camera, but what's really needed is a closer focus point that'll include the foreground objects in the DOF.

I don't have a chart for that lens, but I seem to remember that a focus point distance of about 20-25 ft would give DOF coverage of close objects. Instinctively that seems to be too close to give DOF coverage of the far field, but apparently it's not. Then again, maybe I need to get better at reading hyperfocal charts :? .

B&W is an interesting alternative, but IMO I'd say that this shot doesn't have anything like the atmosphere of your previous colour ice house shots.

Nightski

I agree, RG. There are some things I don't have right. I want this shot to be about the drama of that current going out towards the ice house ... the ice getting darker ...

I wanted to get my phone out of my arm holder so badly, so I could check my DOF on the app ... but I was afraid I'd slip on the rocks in the rapids and drop it.

Next time I'll check while I'm still on shore.

I think the thing that ruins the shot is my water speed. It's neither here nor there.

I did b&w ... which I am not very good at ... because of the ugly dead stuff on the rocks and because the house is a bright mint green ... but now that I think about it, that might be kind of cool.

I might try again tomorrow if the house doesn't sink and if I have fog again.

photoninja1 Loc: Tampa Florida

If I'm reading my hyper focal distance calculator correctly... If you focus at 15 feet at f16, you'll be in focus from about 12.5 feet to infinity. It's a handy little app for this kind of shot. At a 20 foot focus point, the rocks would be just out of acceptable focus, but R.G. definitely has the right idea. I might push this to f22, but it depends on the lens. Diffraction could be a problem at small apertures. You just have to do your own testing to find out.

Nightski

I was at F22 on this one. The rock is in focus. I should have remembered that download box. But the point is to focus at something 15 feet away with my 100mm at F/16 to achieve infinity.

R.G. Loc: Scotland

I just snuck away and checked out a hyperfocal chart.

For a FF sensor and a focal length of 100mm (which is quite long for this type of shot), at f/16 the focus point should be 19.5 metres away, and at f/22 the focus point should be 14.2 metres away.

These values are optimised to give the DOF extending to infinity. I suspect that to optimise sharpness in the foreground it would be quite a bit closer with both apertures. It looks like you needed the f/22 to stretch the DOF far enough both ways.

I don't think there was much that you could do with the water. It looks like the eddies were producing standing waves which would look static at any shutter speed.

Hopefully the darkening is just due to the surface snow and frost cover being thinner than usual. Hopefully the ice is close to its normal thickness. And hopefully the guys are savvy and know to check the thickness of the ice, and how to read the creaks and groans that the ice makes.

Nightski

RG ... metres ... speak in English please. :-D

Nightski

That's what I was thinking. I could have used my 50mm, but I wanted to bring that fish house in closer to the open water ... drama you know...

R.G. Loc: Scotland

These values seem quite a bit bigger than yours. 19.5 metres is more than 60 ft. But this is what the chart said for a 100mm focal length with a FF sensor. Are you sure you're not reading crop sensor values? I'm not because I had to select FF which I know your 6D is. And I had to insert the 100mm myself because it wasn't one of the given values.

R.G. Loc: Scotland

This is the chart I'm using. You can change metres to feet and it gives the same results. Select FF, overwrite 135mm with 100mm and click the calculation button (the yellow button that says Calculate Hyperfocal Distance).

http://www.cambridgeincolour.com/tutorials/hyperfocal-distance.htm

Nightski

I was teasing you about the English ... thought for sure you'd catch that ... LOL. Here's a graphic. When it says focus on the subject, does in simply mean what ever you are focusing on?

(Download)

R.G. Loc: Scotland

If I'm reading it right, the example is for DOF when focusing on your subject. For the hyperfocal effect, you need to choose your focus point to be at the hyperfocal distance, regardless of where your main subject is.

In the example shown, the subject is just slightly farther than the hyperfocal distance, so the DOF extends to infinity in both cases. (Both cases = 1) focusing on subject at 50ft and 2) focusing at hyperfocal distance at 48.7 ft).

In that example, focusing on the subject would give a slightly softer foreground than when you focus at the hyperfocal distance.

Nightski

Oh ... so I should have focused just in front of those rocks ... I focused on them. I know they are sharp. I emailed it to Graham and I am waiting for him to confirm sharpness for me. The image is at my home computer now so I can't allow the download. :-(

R.G. Loc: Scotland

If by "just in front" you mean just beyond, then yes. If the rocks were your priority then they needed to be close to the plane of focus.

However, according to the hyperfocal distance chart, if you'd focused 14.2 metres away at f/22 (or 19.5 metres away at f/16), the rocks would still have been acceptably sharp (open to interpretation), and the DOF would have extended all the way out to infinity.

When the focal point is between the rocks and the ice house, the sharpness is shared by both of them, but where you want optimum sharpness depends on your priorities (i.e. which one is the main subject). Using the hyperfocal distance is a way to optimise the range of the DOF rather than optimising the sharpness at a specific distance.

Nightski

Okay, lets say I don't have to have the rocks, but I focus on them. I would have the water/ice line in focus to infinity. That's what I really want. I also want a faster shutter speed. I think freezing the water motion is the way to go with this shot.