Church interior photography

[Rent]

In the next few weeks I shall be photographing the interior of our local church with our camera club
Last time I did this I was using film with a fully manual camera and a separate light meter.
I am now using a Canon 50D how do I determine exposures over one minute long ?
Thanks in anticipation
Roy

[chauncey]

https://www.youtube.com/watch?v=B4EsDujVSQk

[JohnRostron]

From the limited experience I have had of photographing church interiors, I have never had to use such a long exposure. I tend to use an ISO of 800 or 1600 which allows exposures of 1/20 to 1/125 at around f/4. If you are using a tripod, then you should be able to use smaller ISOs and still be well within your camera's time settings. When necessary I use HDR to cope with windows as well as the interior walls.

[Rent]

Chauncey Sorry does not help with long exposures

[chauncey]

Does your camera have the ability to expose a histogram in live view?

[DanK]

how do I determine exposures over one minute long ?

Boost ISO to take a reading, do the arithmetic, and set the ISO back down.

Each doubling of ISO corresponds to a halving of shutter speed. So, increase the ISO as much as needed to allow the camera to give you a reading. Then put it back where you want it. Leave the aperture unchanged, but double the length of time the shutter is open for each stop you decrease ISO. For example, if you take a reading at ISO 800 but shoot at ISO 100, you would double the shutter interval to get to ISO 400, double it again to get to 200, and yet again to get to 100.

You can avoid the arithmetic by setting ISO 6 stops higher when you meter. Then the reading you get in seconds will be approximately the shutter speed you need in minutes. (That's because 2^6 = 64, and there are of course 60 seconds in a minute.) For example, if you get a reading of 1/4 second at ISO 6400, you would shoot at 15 seconds at ISO 100. I do this often in night photography, which I almost always shoot at ISO 100. It's faster than doing the math.

If I recall, the 50D has shutter speeds up to 30 seconds, so this will give you exposures up to 30 minutes.

BTW, I had a 50D for years. Loved it. However, it doesn't handle high ISOs well. I found it could handle very long exposures well as long as I kept the ISO down, and I generally shot night photos at ISO 100 or 200. Here is a 6-minute shot I took (raw) with the 50D at ISO 200. If I recall, I used no postprocessing noise reduction--I generally don't--but I probably did use Canon's subtractive long-exposure noise reduction, which doesn't reduce detail. It's very clean.

[James G]

Roy,
Dan has given you a fairly definitive response,

I photograph a lot of Stained Glass, and usually take some general shots of interiors for reference.

In this context I usually want to be able to 'see' the glass in the 'architectural' setting of the space, so I am not necessarily looking for perfect architectural detail.

My usual practice is to spot meter, (normally for an iso range of 100-200 at f8,) for the darkest areas, those that have 'average' lighting, and then for the brightest (none glass) areas. I shoot a sequence of 3 captures using these three values and blend them in PP.

In pp I usually find I have to selectively reduce the window brightness to bring out an acceptable level of detail for the stained glass to look 'right' in the context of the interior illumination.

On a few occasions, because of the size of the space I shoot a sequence that that can be stitched to create a panorama, but I still use bracketing each capture in the capture sequence.

I always mount the camera on a tripod and use a cable release, though for the longer exposure times this is probably overkill.

[William W]

. . . You can avoid the arithmetic by setting ISO 6 stops higher when you meter.

Clever. Thank you.

WW

[Manfred M]

+1 to Dan's comments

Your camera should be able to handle anything up to 30 seconds automatically. Anything longer will have to be calculated manually, as Dan has suggested and then shot manually using "bulb" mode on the camera. I would suggest a remote release to reduce the risk of camera shake; you can get fairly inexpensive cable ones from companies like Velo and use your watch to measure the timings. A more expensive intervalometer can automate the timing part; I have a Velo unit here too.

One advantage of really long exposures is that they can mask people (i.e. they move out of the frame before they impact the image).

The other issue is the dynamic range with regard to the impact of windows. If these cannot be avoided, I would shoot the church and windows separately (properly exposed) and then blend the resultant images in post. I use manual blending as the results are far more realistic than HDRI.

Also remember to account for perspective distortion and leave enough space to make corrections, as necessary.

[Rent]

Thank you Dan and Manfred. Just what I needed, though why I didn't think of it myself I don't know
Roy

[William W]

Additionally . . .

If you have the time and especially IF your aim is to make one shot at a low ISO, (but also useful for the individual files of blended shots) and if you are pedantic then:

a) Reciprocity Effect does apply. (just please trust me - I cannot find the Canon White paper).

b) Histograms represents untruths apropos ETTR (please trust me again. Short explanation: each Canon EOS Digital camera I have owned, had a different "headroom" - and I have owned a 50D. Additionally Histograms are generated by the JPEG and as such, are a result of the in-camera JPEG Post Production algorithms and settings).

An elegant solution is to calculate the exposure to assume the farthest ETTR and then shoot an Exposure Bracket on SHUTTER SPEED: ±⅔ Stop usually does the trick for Interior Very Low Light / High Dynamic Range shooting at ISO100.

Personally, if using TTL Metering I also use the Spot Meter Mode to make several readings and then manually calculate the exposure for the scene.

NB:

1. Using TTL Metering on any camera, then the "Spot Meter MODE" is affected by the Focal Length of the lens used.

2. On Canon DSLRs the "Spot" is a percentage coverage, not an AoV;that percentage may differ between canon camera models - although on a 50D it is pretty tight (small).

3. On Canon DSLRs the "Spot" is a weighted percentage coverage - i.e there is an algorithm which takes into account of a reading of the area OUTSIDE the small percentage circle reading at the centre of the viewfinder

4. The main point being IF you used a Spot Meter or an Hand Held Meter with a Spot Attachment in film days, then an SLR TTL "Spot Meter Mode" is not exactly the same

5. Especially be aware of "Spot" readings made when using a W/A or Normal Lens . . . remember that the "Spot" is a "weighted" reading.

WW

PS - if you do not have a Remote Release (but I do suggest you buy one) - but if you don't want to, then use "Mirror Up" and the delayed shutter release, that will work for exposures up to 30 seconds - not my idea, that's a tip I picked up from Richard Crowe a few years ago.