The standard applied to misapprehensions of evidence
advanced in support of a claim that a miscarriage of justice has
occurred is a stringent one. The misapprehension of the evidence
must go to the substance of the evidence, not simply to its detail.
And the misapprehension must be material rather than peripheral
to the reasoning of the trial judge. But there is more. And that is
that the errors must play an essential part, that is to say, a role in
the reasoning process resulting in a conviction, not just in the
narrative of the judgment: Lohrer, at para. 2. Said in another
way, a misapprehension of evidence amounts to a miscarriage of
justice only if striking it from the judgment would leave the trial
judge’s reasoning on unsteady ground: R. v. Sinclair,  3
S.C.R. 3,  S.C.J. No. 40, 2011 SCC 40, at para. 56;
R. v. Bains,  O.J. No. 2091, 2012 ONCA 305, 291 O.A.C.
135, at para. 15.
 Something should also be said about the principles that
govern use by the trier of fact of real evidence, in particular, video
images, as evidence of a person’s identity.
 Photographs, video recordings and other video images are
real evidence, that is to say, evidence that conveys a relevant firsthand sense impression to the trier of fact. They are also, to a certain extent, testimonial evidence: Nikolovski, at para. 28.
 It is well settled that a trier of fact, in particular, a judge
sitting without a jury, may identify a person depicted in a photographic image as an individual who appears in the courtroom.
That person may be an accused: Nikolovski, at para. 30;
R. v. Slater,  O.J. No. 2143, 2010 ONCA 376, at para. 3. But
there would seem to be no reason in principle to limit this authority
to identification of an accused as the person responsible for the
commission of an offence.
 Caution is required when a trial judge considers visual
images as evidence of identification. The clarity and quality of the
image may not be good. There may be changes or differences in the
appearance of the persons involved: Nikolovski, at paras. 30, 32.
The principles applied
 I would give effect to this ground of appeal.
 The respondent concedes that the trial judge misapprehended the evidence about the photograph on which G.D. was
cross-examined. The photograph was in fact put to G.D. in cross-examination and was part of a series of related photos entered
into evidence through the private investigator’s report. In the
photo put to G.D., she identified the persons depicted there. She
acknowledged that the photo appeared to have been taken in the
basement of the appellant C.B.’s home.