What this planner works out
This planner totals the images a scene will produce from the overview, mid-range and close-up counts, and estimates the storage they will occupy.
Scene photography follows a three-tier convention: overview establishing the scene, mid-range relating items to their surroundings, and close-ups of each item with and without a scale. This is a teaching and planning aid, not a casework tool.
Photography plan
Before you plan
- Close-ups per item should account for the convention of photographing with and without a scale, and from more than one angle where relevant.
- Average file size depends on the camera and format. RAW files are typically 20 to 50 MB; JPEG considerably less.
- Plan storage for at least two copies. A single card or drive is a single point of failure for irreplaceable material.
- The count is a planning figure. Real scenes generate more images than planned, not fewer.
Each tier answers a different question. Overview images show what the scene was; mid-range images show where an item was in relation to fixed features; close-ups show what the item is. A close-up without a mid-range image linking it to a location is far weaker evidence, which is why the sequence matters as much as the images.
How this calculator works
A total and a storage estimate:
Total images = overview + mid-range + (evidence items × close-ups per item)
Storage in MB = total images × average file size
Storage in GB = MB ÷ 1,024The calculation covers a single set. Shooting RAW plus JPEG doubles the storage, and the convention of retaining originals unaltered means working copies are additional again.
Worked example: a scene with 25 items
Using the default figures — 20 overview, 40 mid-range, 25 evidence items at 3 close-ups each, averaging 12 MB:
- Total images: 20 + 40 + 75 = 135
- Storage: 1,620 MB, or 1.58 GB
1.58 GB is trivial for a single card, which is the point worth noticing: storage is not the constraint. Time is. At even a minute per image including composition, scale placement and checking, 135 images is over two hours of photography — and that is before the search that finds the items in the first place.
Common mistakes
- Photographing close-ups without mid-range context. The link to location is lost.
- Omitting the scale, or including only scaled images. Convention is both.
- Planning for one copy. Irreplaceable images need redundancy from the outset.
- Underestimating the time rather than the storage. Time is the binding constraint.
- Editing originals. Originals are retained unaltered and work is done on copies.
Frequently asked questions
Why photograph with and without a scale?
The unscaled image shows the item as found, without anything introduced into the scene. The scaled image allows measurement and comparison. Taking both means neither can be criticised — one demonstrates the item was not disturbed to place the scale, the other supports analysis.
What image format should be used?
RAW where the camera supports it, because it preserves the sensor data without lossy compression and supports later analysis. Many practitioners shoot RAW plus JPEG so a viewable file exists immediately. Whatever the format, the originals are retained unaltered and any adjustment is documented.
How is image integrity maintained?
By retaining originals unmodified, working only on copies, recording any processing applied, and maintaining continuity of the storage media in the same way as any other exhibit. Hash values are sometimes used to demonstrate that files have not changed.
How many images is too many?
There is no such thing in principle — storage is cheap and an image not taken cannot be taken later. In practice the constraint is time at the scene and the burden of reviewing and disclosing a very large set. Structured shooting to the three-tier convention keeps a large set navigable.
Is what I enter stored?
No. Everything you enter is processed in your browser and is never transmitted or retained. Even so, treat any public website as an unsecured environment and do not enter identifiable case information.
Related tools
References
- GOV.UK — Forensic Science Regulator codes of practice on imaging and continuity
- Health and Safety Executive — safe working at scenes, including lighting and hazards
Sources are checked at publication and can change — how I choose and check references.