

SLR Camera Simulator - kmfrk
http://camerasim.com/

======
podperson
It's kind of a nice idea and a decent start. It doesn't seem to do depth of
field very well (f8 should make the background pretty sharp at 43mm; f2.8 at
200mm should have a completely blurred background).

It would be nice if it showed non-Canon terminology (Canons say "Tv" while
almost all other cameras say "S", for example), at least as an alternative. It
should also visually indicate the value being automatically chosen in the
different modes.

No P (program) mode. This is actually the most useful shooting mode on many
DSLRs, especially for novices. It lets you trade off aperture vs. shutter
speed.

__Advanced Nitpicking__

No auto ISO mode. (Great feature of Pentax cameras -- it's like M but the
camera picks the ISO that will work.)

No ISO-priority mode.

It doesn't allow for things like camera shake and the child's motion (you
might pick 1/60 of a second to capture the child sharply, while needing 1/250,
say, for the pinwheel).

It's not worth allowing ridiculously high (small) apertures (e.g. f29) -- if
you're not going to do diffraction, so I'd stop at f22. It would be nice to
have faster (bigger) apertures than f2.8 to really show the benefits.

It shows autofocus points, but they don't do anything. It would be interesting
to allow the user to pick a focus point and assume the metering is weighted on
that position, but that's getting pretty advanced.

~~~
zalew
> No P (program) mode. This is actually the most useful shooting mode on many
> DSLRs, especially for novices. It lets you trade off aperture vs. shutter
> speed.

oh boy. that's actually the mode that keep novices clueless about what's going
on with the settings.

> No auto ISO mode, No ISO-priority mode, etc. etc.

well, ISO + TIME + APERTURE are ingredients of EXPOSURE, and that should be
all you need to know to start shooting. you know this and you can grab the
newest high-end dslr or your grandpa's 35mm oldie and know what you're doing.
the rest is just geekery.

~~~
defroost
> oh boy. that's actually the mode that keep novices clueless about what's
> going on with the settings.

Of course. Criticizing it for not having Program mode stuck me as similar to
saying "Nice sportscar, if only it had Automatic transmission". People buy
high end DSLRs and don't take the time to learn what the various A-S-M-P modes
do. It is the fault of the mode and the manufacturers who put P or Green modes
on the SLRs, and recommend them as idiot proof modes.

~~~
eftpotrm
I know how to use my SLR, I regularly use it in full manual tuning every last
exposure variable in manual focus, sometimes with multiple manual flashes too.

Yet, I still try to remember to leave the camera in P when I put it away and
often shoot in P. It's a relatively idiot proof mode; it's unlikely that, if I
just pick up the camera and shoot because I'm in a hurry for whatever's in
front of me, P will give me a ridiculous, unusable exposure.

------
angusgr
Given this is intended to teach exposure/DoF, it'd be nice to be able to
bypass the "SLR" aspect of the camera, ie provide a "continuous snapping" mode
where moving a slider instantly updates the "photo" instead of showing the
fake autofocus sensor overlay.

It's definitely a neat way to interact with it in a browser, though. If you're
looking to learn these relationships in a less interactive way, I thoroughly
recommend the book "Understanding Exposure" by Brian Peterson.

~~~
ujal
That was also my first thought. The app would be much more informative by
providing the results instant.

------
sbierwagen
The noise at higher ISO levels isn't terribly realistic for modern SLRs, let
alone full-frame pro SLRs.

Here's a comparison of several modern entry-level SLRs:
<http://www.dpreview.com/reviews/nikond5100/page20.asp>

You can go up to ISO 1600 and get (more or less) unnoticeable noise.

Note that you have to switch to RAW to show sensor noise-- JPEG mode will blur
away noise, trading fine detail for smooth images.

Also that lens is really amazingly sharp at both ends of its aperture range.
In the real world you wouldn't get anywhere near that level of performance
without spending tens on thousands of dollars on a prime (non-zoom) lens.

~~~
ashchristopher
It's a learning tool. Cut them some slack =).

~~~
sbierwagen
It's a learning tool, and so I would like it to teach that almost all lenses
made of mortal glass are less sharp at either end of their aperture range; and
that taking a picture of a landscape on a sunny day at f2.8 is a bad idea.

------
sasha61
If you have ipod/iphone/ipad, have a look at
<[http://www.islap101.com/>](http://www.islap101.com/>); (and review of it at
<[http://lifehacker.com/5501364/photo-tutor-teaches-basic-
came...](http://lifehacker.com/5501364/photo-tutor-teaches-basic-camera-
exposure-on-the-go-from-your-iphone>). There are actually two apps (one for
shutter speed and one for aperture) - and they teach/display those concepts
really well - even if I say so myself :-). There are also "recipes" for taking
photos in various environments/situations - all prepared by professional
photographers.

------
niels_olson
Best review of the basic science I have seen online:
<http://johnlind.tripod.com/science/>

The the lens calculations are a whole 'nother ball of wax, but here's the
quick skinny on the exposure value system:

Av + Tv = Ev = Sv + Bv

Exposure value: Ev

Aperture value: Av = log2 ( _f_ ^2)

Time value: Tv = log2 (1/t)

Speed value: Sv = log2 (0.32 * ISO)

Brightness value: Bv = subject luminance in foot-Lamberts

------
alok-g
Nice idea.

A difficult one from implementation standpoint: When I change the distance, it
just scales the girl's face as a 2D image -- no perspective. :-) I'm not being
picky, just that this is sometimes a consideration for me when clicking...

Wish someone can point me to the mathematics behind this stuff. I figure ISO
means gain of some amplifier inside so less photons would be needed to get to
the same voltage at the expense of more noise. I can see how with the two auto
modes, aperture size and shutter speeds relate to each other (basically you
need to gather a similar number of photons, given the ISO setting). Yet do not
know the mathematics behind why aperture size affects the depth of focus.
Likewise, why focal length does the same. What's the mathematical definition
of Fstop. And last but not the least, what role the sensor size play into all
of this.

~~~
sbierwagen
[https://secure.wikimedia.org/wikipedia/en/w/index.php?title=...](https://secure.wikimedia.org/wikipedia/en/w/index.php?title=F-number)

<https://secure.wikimedia.org/wikipedia/en/wiki/Focal_length>

[https://secure.wikimedia.org/wikipedia/en/wiki/Depth_of_fiel...](https://secure.wikimedia.org/wikipedia/en/wiki/Depth_of_field)

[https://secure.wikimedia.org/wikipedia/en/wiki/Film_speed#Di...](https://secure.wikimedia.org/wikipedia/en/wiki/Film_speed#Digital_camera_ISO_speed_and_exposure_index)

~~~
alok-g
This helped:
[https://secure.wikimedia.org/wikipedia/en/wiki/Depth_of_fiel...](https://secure.wikimedia.org/wikipedia/en/wiki/Depth_of_field#Derivation_of_the_DOF_formulas)

Still do not know how sensor size affects things. Will read more, and
hopefully will be able to construct a single mathematical model that couples
all of these together.

------
drblast
Can anyone explain why the "ISO" setting exists on digital SLR cameras? It
seems like this is an unnecessary holdover from film cameras.

I ask this as an owner of a Canon Digital Rebel that knows very little about
photography. What does changing the ISO setting get you that changing the
exposure time or aperture wouldn't?

~~~
sbierwagen
ISO is sensor sensitivity. Higher settings multiply the numbers that come from
individual sensor elements by increasingly large amounts.

Image sensors are not perfectly noiseless, of course, and the higher the ISO
is, the noisier the image, which appears as random speckles of colored dots.

You don't notice the difference, though, because you're probably shooting in
JPEG mode, not in RAW. In JPEG, the Rebel tries very hard to cover up its
sins, and will blur away sensor noise, which is hard to notice unless you
grovel over areas of fine detail at 400% magnification.

Second time I've linked this in this thread, but
<http://www.dpreview.com/reviews/nikond5100/page20.asp> shows some great
examples of what sensor noise looks like over a range of ISO values.

Edit:

Useless editorializing: A SLR isn't a great purchase for someone who knows
very little about photography. A point-and-shoot is lighter, cheaper, more
durable, easier to use, and in the vast majority of situations, will produce
identical results to a SLR. You then graduate to a real camera when get fed up
with the various fiddly technical limitations of a point-and-shoot; and bonus,
you still have the small camera, which is the one you take with you when
climbing mountains, or on vacation, rather than lugging around five kilograms
of japanese glass.

Tedious polemic: I dearly hope you have more than one lens. The enormous price
premium of a SLR is mostly for the privilege of being able to change lenses.
If you just stick with the kit lens, then you will have spent rather a lot of
money to accomplish nothing a point-and-shoot couldn't do.

~~~
bradleyland
Just as a counterpoint (not to pick a fight), I'd disagree with a lot of what
you said in the latter portion of your post.

Entry level SLRs are great, even for people who don't know anything more than
point-and-shoot. The advantage of an SLR is that it will focus faster, meter
faster, and ultimately take the photo faster. This is a huge advantage for
parents, whose children are fast moving targets.

What's not necessarily a good idea, is buying the biggest, most expensive SLR
you can find. Canon and Nikon both make entry-level SLRs that have modes
specifically targeted at novice photographers who will never leave full-auto
mode. Buying a more expensive model primarily gets you features. Features that
you won't use. The hardware is remarkably similar until you get up in to
cameras that cost thousands of dollars.

Many people believe that the huge lens is what makes SLR photos clearer in
more conditions, but that's not the whole story. The lens is large because of
an aspect of the SLR that you'll probably never see: the sensor. The single
greatest reason for the increased image quality of an SLR is sensor size. When
you shoot with a compact point-and-shoot, you're capturing light with a sensor
the size of your pinky fingernail. You could shoehorn the fastest, largest,
most expensive SLR lens on to a compact point-and-shoot, and the photos it
takes wouldn't compare to an SLR with even a modest lens. The sensor in an SLR
camera is closer to the size of a postage stamp, and this makes all the
difference.

Keep in mind that compacts these days shoot comparable resolution (megapixels)
to SLRs. This means that each "pixel" in a compact is microscopically small
when compared to the "pixels" in a SLR sensor. This means less area for light
to fall, and less light collected.

So, even with one lens, and in the hands of a novice, a reasonably priced SLR
can result in sharper, more well timed photos in a more diverse range of
conditions.

~~~
ajkessler
Also not to pick a fight, especially since your post has a lot of merit if
this were 2009, but point and shoots and bridge cameras have come a long way.
You can essentially get all the benefits of an SLR in the higher end point and
shoots for several hundred dollars less than even entry level SLR kits. There
are a number of point and shoots with the same size sensors as entry level
DSLRs, same instant on, equivalent lack of shutter lag, equivalent metering,
etc. etc.

For most people, the upsell to the DSLR probably isn't worth it at this point.

~~~
barrkel
There's a tradeoff between the physical size of your lens, the physical size
of your sensor, and your maximum optical zoom. The way you put it, you make it
sound like you can have it all in a compact, but that's just not the case. A
bridge camera with a substantial zoom and large sensor size will be as about
as big as a DSLR with a lens of similar capability. A compact point and shoot
will either have a smaller sensor or a less capable optical zoom, and probably
both. I have a fairly high end compact, albeit one from late 2009 (Canon S90),
and it is nowhere near as capable as an entry-level DSLR in terms of focus
speed, continuous shot rate, instant on etc.; and the S95 from late 2010 isn't
much more capable (720 HD video, stereo mics and firmware update).

~~~
ajkessler
Well of course not. You also don't get interchangeable lenses. I never said
you could get it all in a compact.

My point was, for most people (particularly those who this neat little program
was made for), the quality in the high end point and shoots is there. The G12
I used late last year performed very well in all of the categories you
mentioned. And for nearly half the price of a basic dslr kit, by the time
you're all done with it.

~~~
barrkel
<http://www.imaging-resource.com/PRODS/G12/G12A6.HTM> indicates that G12 power
on to first shot is in the region of 2.7 seconds. I can turn on my D90 and
take a shot in a single continuous move of picking it up and aiming it -
[http://reviews.cnet.com/digital-
cameras/nikon-d90-with-18/45...](http://reviews.cnet.com/digital-
cameras/nikon-d90-with-18/4505-6501_7-33232672.html#reviewPage1) says it's 0.2
seconds, though with AF added in, I'd say it feels more like 0.9. Somewhere
between 15x and 3x faster makes a huge difference in reacting quickly in e.g.
a party, or sport. The D90 gets over 4 shots per second continuously, but it
seems that the G12 has a hard time getting 2. The sensor is also pretty small
(AFAIK it's the same as the one in G11 and S90); that lets it get higher zoom
levels at the cost of quality in low light. All that in a pretty bulky package
(IMO - it's bigger than the S90, nearly twice the weight, and the S90 isn't
exactly small).

What I'm getting at here is that if you're walking about on holiday in a city,
something like the S90, or maybe the G11, would make sense (though I think the
G11 might be a little too big for comfort, the S90 is already quite a bit). If
you're specifically trying to take photos, rather than just bringing a camera
along, then you have a lot more freedom with a DSLR.

~~~
ajkessler
My point is that, for people who don't know how aperture, ss, and iso affect
exposure, the 2.5 second difference in startup time and the 2 fps difference
in burst probably isn't going to make a big difference in their user
experience.

Of course you're going to have more freedom with a DSLR. That's the whole
point. But, if you can't figure out what the aperture dial does, the freedom
is probably going to be lost on you, along with the extra $400 you're going to
spend.

I'm not anti-DSLR or anything. I've probably bought and sold $50k worth of
gear in the last 5 years. DSLRs are awesome and they keep getting better. But,
compact cameras have gotten pretty damn good in the last couple of years. For
many people, and many different applications, they will fit the bill. If
you're a sports shooter, they certainly won't.

~~~
bradleyland
I feel like you're getting piled on, sorry. Although I guess someone would
have come along and made the point.

I don't disagree with you entirely. There are APS-C compacts available that
have many of the advantages of a DSLR, but I can't see where buying something
like a G12 for $500 makes sense when a Nikon D3000 is available at the same
price point.

My opinion is that if you need a compact, get a compact. Pick up a Canon
SD1300 for $150 and go crazy. I did a (personal, not school) photography
project with my SD870IS and took some of the best photographs of my life.

However, I feel that parents, especially, can benefit from a DSLR,
specifically because of the speed. My mother bought a Nikon DSLR a couple
years ago at my recommendation because she complained of "always missing the
shot she wanted" with her Canon compact. She's been thrilled with her DSLR
because she can pick it up, flip it on, and start shooting. There's no waiting
for a screen to come on, she simply flips the switch that is right under her
index finger, looks through the viewfinder, and pulls the trigger. When your 4
year old grandson is doing something adorable in the living room, the
difference between compact speed and DSLR speed _does_ make a difference.

~~~
ajkessler
I see your point completely. I will say that the best camera is the one you
have with you. The reason to buy a G12 over a d3000 is because you can
literally fit the G12 in a pocket (although not the most comfortable solution)
or in even a small purse. You can't with a d3000. It's something you have to
always consider "Do I want to take this with me?"

I was not clear above in the discussion of image quality (got sidetracked with
more or less irrelevant arguments about sensor size/dynamic range/etc.). I was
attempting to say that image quality as a whole from the higher end point and
shoots is on par with DSLRs for almost everyone. See here for a comparison
with the 2 generation old G10 v. a $40k medium format rig:
<http://www.luminous-landscape.com/reviews/kidding.shtml>

~~~
bradleyland
Looks like we agree on a lot :)

I take up photography in stints of a few weeks to a few months. I get inspired
to do some photography, take some photos, then leave it for other pursuits.
The last time I took it up, my gut reaction was that I needed to replace my
old Canon A1 with a modern DSLR. Prices had come down significantly, and I
couldn't possibly do good work with my compact, right?

Well, rather than rushing out and buying a DSLR, I decided to go shoot with my
compact SD870IS. I'm so glad I did. It gave me a chance to re-focus on the
basics without worrying about what settings I was using. I left the camera in
full auto and focused instead on LOOKING at what I was about to shoot. I was
really pleased with the result, and I'm 100% convinced that it improved my
photography as a result.

Some examples of the photos I shot with the SD870IS:

[http://www.flickr.com/photos/bradleyland/3224710694/in/photo...](http://www.flickr.com/photos/bradleyland/3224710694/in/photostream/lightbox/)

[http://www.flickr.com/photos/bradleyland/3224711584/in/photo...](http://www.flickr.com/photos/bradleyland/3224711584/in/photostream/lightbox/)

[http://www.flickr.com/photos/bradleyland/3223853289/in/photo...](http://www.flickr.com/photos/bradleyland/3223853289/in/photostream/lightbox/)

[http://www.flickr.com/photos/bradleyland/3224779424/in/photo...](http://www.flickr.com/photos/bradleyland/3224779424/in/photostream/lightbox/)

I could not have taken the shot of the grasshopper with a DSLR because A) I
wouldn't have been able to grab the camera, mount a macro lens, and get ready
to shoot in time, and B) the DSLR wouldn't have fit in the space I had to put
the camera to get that shot.

Then again, I couldn't have taken these shots with the compact because I
couldn't quickly change settings for good DOF (first photo) and I'd have
missed the moment because of speed (arguably for both).

[http://www.flickr.com/photos/bradleyland/3296469446/in/photo...](http://www.flickr.com/photos/bradleyland/3296469446/in/photostream/lightbox/)

[http://www.flickr.com/photos/bradleyland/3241790710/in/photo...](http://www.flickr.com/photos/bradleyland/3241790710/in/photostream/lightbox/)

------
bcaulf
The beauty of digital photography is that you can take pictures all day at no
cost and see your results instantly. So instead of running this program, get
your friend with an SLR to go on an outing with you and let you do most of the
shooting.

Go outside and fill up a memory card while you systematically work through the
settings. After you get the hang of exposure you can start in on the different
settings for metering, autofocus, manual focus, jpeg processing, black and
white, motor drive, use of flash, different lenses, not to mention composition
choices, interacting with the subject, use of filters, creative panning or
rotating. Real photography is more fun than tweaking sliders on a flash app.

------
kenjackson
I don't know much about cameras, so I don't know how accurate it is, but I
love the idea. Kudos for this idea and the execution seems good. I like.

~~~
hackermom
Reasonably accurate.

add.: it gives a good foundation regarding teaching exposure itself, but,
apart from not explaining (nor visualizing) that focal length and perspective
are two separate attributes of optics, it also misrepresents the meaning and
function of the ƒ value in a very common way often repeated even by seasoned
photographers, in that it suggests (and indirectly claims) that ƒ only has to
do with the aperture of the lens, and that ƒ is an indicator of what depth of
field you will have. In reality, ƒ only tells you how much light is passed to
the film plane; it does not tell you the state of the lens' aperture, nor does
it say anything about the depth of field. This misleading explanation
regarding ƒ is widespread even in literature.

~~~
sasha61
Actually this is not quite correct. F is ratio of aperture to focal length. As
such, it does not tell you the absolute values of either, but it definitely
does relate to DOF (although this will be affected by the focal length value -
e.g., for the same F, you could have DOF of a few mm at short focal length,
and a few dozen metres with long zoom lenses).

~~~
hackermom
It's entirely correct. ƒ relates to DoF only in that it's relative to the
maximum aperture of a specific lens. Without knowing the specifics of the
lens, you cannot know from arbitrary ƒ value if the aperture has been
contracted (narrowing the flow of light, thus increasing the DoF), if it's
just really dark glass in the lens, if someone has a TC mounted that steals
1-2 exposure stops, or if someone has simply used a gray filter or two
attached to the end of the lens. I can produce two identical exposures, both
of ƒ/8.0, where one has a narrow DoF and the other 4 aperture steps deeper
DoF, by simply using a gray filter in one shot, and contracting the aperture
in the other. In a third example I can use a very, very dark lens such as f.e.
what Leica used to produce in the 60s, still exposing at ƒ/8.0 in wide-open
aperture, reaching the same exposure and achieving a narrow DoF (contrary to
what anyone would think just knowing it's ƒ/8.0), but without having stopped
down a single step and without having used gray filters.

~~~
lutorm
I don't get it either.

 _ƒ relates to DoF only in that it's relative to the maximum aperture of a
specific lens._

No, the f/ratio _is_ f/D, which determines the divergence angle of the ray
bundles that end up on the detector plane, and this is what determines the
depth of field. You can not produce two exposures that have the same focal
length and f/ratio that have different depths of field. Adding an ND filter
will just make one image darker, it will not change the depth of field. You
can't change the aperture without changing the f/value, because the f/value
_determines_ the aperture.

~~~
hackermom
_"You can not produce two exposures that have the same focal length and
f/ratio that have different depths of field."_

I am not sure why we are both establishing to one another that DoF is
determined by the dispersion of the light hitting the film plane when we
already know this. My Mamiya Sekor 50mm ƒ/6.3 has a DoF not even tangibly
different from my Nikkor 50mm ƒ/1.4, unless I stop the latter down to ƒ/6.3
which produces two identical exposures at same ƒ/ratio but with very different
DoF.

~~~
ajkessler
This is simply not true. If you stop your Nikkor down to 6.3, it will have the
identical depth of field as your Mamiya does at 6.3.

~~~
eftpotrm
No; the larger sensor size of the Mamiya as a medium format camera will give
less depth of field for a given aperture than the 35mm Nikon.

Otherwise you're right, so in the odd circumstance the poster has a Nikkor
50/1.4 medium format or Mamiya small format 50/6.3 then their depth of field
characteristics will be as you said. I'm also pretty sure that even on 6x7
50mm @ f/6.3 wouldn't give DoF characteristics anywhere near 50mm @ f/1.4 on a
DX sensor (as the extreme examples to artificially push them closer together),
and they'd have a radically different field of view.

~~~
ajkessler
Well yes, but we're talking all other things being equal.

------
chrishaum
This is an awesome tool. Thanks!

------
SonicSoul
im a DSLR newb, but i think i just nailed it with: sunny, 55mm, ISO:100, f4,
1/2,000

~~~
mTh
Kudos. But if you are a newbie, then perhaps it would be more useful for you,
in order to learn how to use an actual DSLR in the field, to reduce the
'Lighting' to more difficult situations ('Overcast', 'Bright Indoors' etc.)
and...

1.) set up the simulator to Tv mode and play with the 'Shutter Speed' and ISO
primarily

...and after this:

2.) set up the simulator to Av mode and play with the 'Aperture' and ISO
primarily.

In this way you will learn how far you can go in real situations and what
results you might expect.

HTH

(EDIT: Ok, you can play with the distance & focal length but I think that for
the 1st step it is better to concentrate on the points above).

~~~
SonicSoul
thanks, so why would Tv mode be more educational than M (which I am guessing
stands for Manual) which also allows for playing with shutter speed and ISO ?

~~~
mTh
Indeed there are cases in which one can use the M (Manual) mode. But usually
these cases are rather corner cases, especially for us, the beginners.
Basically you ditch the DSLR's photometric engine which does most of the time
a very good job, (except some rare situations in which the illumination is
very tricky, you want to achieve very special effects etc.).

Besides that, it is enough more difficult to play with four variables
(Aperture, ISO, Speed AND the exposure indicator (usually a vertical beam in
viewfinder)) compared with two variables (ISO & Aperture or ISO & Time
respectively) or with just one (Aperture or Time - if you have the ISO set to
Auto).

The main difficulty here isn't that someone (you) can cope (or not) with four
variables in a simulator but to adjust them quickly and exactly in the field
given the very short amount of time which you (the photographer) have at your
disposition to take "the shoot".

That's why the most photojurnalists (from which, more or less, is your truly
also) avoid the M mode. OTOH, I have very close "brothers" which are 'studio
creatures' which prefer the M mode.

And now to respond directly to your question, having the Tv (or Av mode) will
give you a much 'closer to real' simulation (especially if you are on-field,
on-street, on-sports etc. photographer) and will allow you to concentrate
rather on the effect you want to achieve (for ex. how to simulate a good
moving effect of the child's rotating toy) in the smallest amount of time
(think that in the real world, the children aren't so frozen like the one in
our simulator :-) ) and not to concentrate so much in obtaining a correct
exposure. Usually the metering system does the job rather well. These systems
have enough advanced features today to help you in avoiding the M mode with
its quirks: exposure modes, over/underexposing by 1/2, 1/3 EV etc.

HTH

PS: Disclaimer: No, I'm not against the M mode. But I want to stress its
limited usage today. Of course IMHO.

