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Comment by chwahoo | Hacker News Reader

You can change the aperture in this simulation. Perhaps it was just grayed out since you were in shutter-priority mode?

No see you're as confused as she was :) Most zoom lenses are variable aperture, e.g. at 18mm they will open up to f/3.5 but at 55mm they will only open up to f/5.6. The simulation doesn't address this, and it can be surprising for a beginner to see the aperture changing as they zoom - they may become fixated on zooming as a way to control aperture without realising they are observing a side-effect.

Unfortunately, I do not completely agree with the post. With the prices of DSLRs coming down, nowadays everyone has a DSLR. And most of them don't give a crap about photography and its internals.

While I agree that constant aperture lenses are substantially costly than their variable aperture counterparts, cameras like Canon 5D Mark III is coming with a 24-70 F/2.8L II lens as a kit.

I'm confused. Are you suggesting that the type of person who would find the camera simulator site useful is likely to be somebody who would own something like a Canon 5D Mark III? That's a $3,500 camera - body only. If you own that camera, I should hope you aren't visiting camera simulator sites, otherwise I suspect you're not going to be putting it to much good use :)

I have come across at least 2 people holding a 1 series camera and shooting in Auto or Programmed Auto modes. And I was severely disheartened.

I am only expecting people who actually have a DSLR with either a variable or constant speed lens but still shoot auto will come and be able to try their hands out on a same scene with similar type of lighting but different shutter speed aperture combinations and later on be motivated enough to try it out on their real camera.

Why would you be disheartened? A lot of photographers (including skilled amateurs and pros) shoot in P mode when the situation allows for it.

Prolific shooters usually know what to expect from their camera, so there's no need to experiment with settings all of the time, and if they see a P mode choice they don't like, they can program shift or switch to A/S/M mode.

I am not aware of your level of understanding of digital photography, so please pardon me. But as far as I understand, an average camera tries to reach the correct exposure by adding everything up to 18% grey. I am intentionally leaving the metering discussions out here for simplicity. So in case your frame contains too much light and shadows, your metering will be thrown off.

I come from an age when SLR cameras did not even have batteries, leave aside digital sensors. So probably it is hard wired into me that I need to use my eyes and brain and leave aside the cameras' when shooting.

You're about right with the 18% grey, but most skilled photographers do rely on the in-camera metering these days, regardless of which P/A/S mode they're using.

They may not use matrix metering (I definitely don't, I use center weighted, and I'm just a hobbyist) but you also have to remember the dynamic range of a full-frame RAW file is pretty good and that you can get good shadow/highlight recovery out of most situations.

When the photographer is chimping the image post-shot, if they see that the exposure is way off, you can still program-shift the settings in P-mode or use the EV dial to make adjustments and reshoot.

You're not at depth limit, HN just limits replies per minute to reduce the incidence of flamewars taking over the page.

Ah cool I see. I'll update as appropriate.

Better lenses are fixed aperture though, so I don't think it's unreasonable to replicate that here. My 24-70 is 2.8 across the board.

Most kit lenses on entry level cameras aren't fixed aperture though - I am guessing this app targets entry level users.

In any case, the need to have fixed fast aperture lenses is diminishing with IS and high ISO performance. I'd rather carry a fixed F4 than a fixed F2.8 zoom with a 2012 camera. It's going to be a much smaller lens and just as effective for most use cases.

While I agree with the point on quality, constant aperture zoom lenses tend to be MUCH more expensive than variable aperture lenses. Your single lens costs more than twice her entire starting kit :) They also tend to have fairly specialist zoom ranges. I find it hard to imagine somebody with a constant aperture zoom lens would find benefit in this camera simulation. The majority of the kind of people using it will be beginners with kit variable aperture lenses.

The most common advice for them would be to get a prime lens. Especially in this simulation that offers both distance and focal length setting (which are, for this scene and 18-55mm focal length, mostly interchangeable), I'd like to have it. It'd also allow you to go (cheaply) to f/1.8 or f/1.4, which would be much better to illustrate the effect that aperture has on the depth of field. With a common f/3.5:5.6 kit lens and APS-C sensor, you won't get a shallow DOF and nice out-of-focus background easily, and that could be frustrating to a beginner. Especially when you learn to do it in this simulation.

>> While I agree with the point on quality

It's important to note a distinction.

The faster aperture tends to necessitate better glass, but the idea that only fast lenses have good glass would not necessarily be true. There are plenty of "slow" lenses that have very good optical quality.

Are you sure? When a lens claims to be f/2.8 at all zoom levels, it usually means that that the maximum aperture (i.e., minimum f-number) is f/2.8. It can do f/11 etc also.

If it is indeed a lens with just a single aperture setting, can you tell me the model number? I'm quite curious now. Thx.

He means that his 24-70 zoom lens has the maximum aperture of f/2.8 at all focal lengths from 24 to 70. Cheaper lens would get to, say, f/3.5 at 24, but at 70, you wouldn't get more than f/5.6, for example. So you can't set it to 70mm and f/3.5, even though you can set it to 24 and f/3.5, because it can't physically do that. Of course you can set it to f/13 or even more, that's easy to do with an ordinary lens. There are some funnier lenses (mirror lenses, for example) that have fixed apertures. It's f/8 and you can't do anything about it, because there is no mechanism that would allow you to cover more or less of space before the sensor (film).

I was only confused about your post :).

It doesn't actually do anything

The aperture on an SLR only closes once you press the shutter release (or press the depth of field preview button, but those are becoming rare on consumer grade hardware). If the aperture closed as soon as you changed it the camera would be unusable because the viewfinder would become very dark, and the autofocus would stop working.

>or press the depth of field preview button, but those are becoming rare on consumer grade hardware

I bought a Nikon D5100 last summer, my first SLR since a Pentax K1000 I had for decades. The lack of a DoF preview button was a little hard for me to adjust to.

Can you expand on that a little... I'm looking to buy a D5100, is this using the LCD or the viewfinder?

I do have d5100 and I confirm that there is no DoF Preview button. You can read about it's purpose here http://www.kenrockwell.com/tech/dof-button.htm If you really need this button d7000 have same sensor and does same quality photos. It allows for more control using physical buttons (in d5100 you need to use info menu to set some setting). It is also better suited then d5100 for manual lenses. That said it is also more expensive and heavier(but is also more water prove). Personally most of the time lack of DoF preview did not bother me because I either wanted as much in focus as possible(for landscapes), or only person in focus which was quite easy. Weak support for manual lenses on the other hand baited me once with out of focus picture that I did not notice until it was to late(if it is really bright outside is hard to see photo on LCD, so i just checked histogram). You can see my d5100 pictures here https://plus.google.com/100147104412340662455/photos if you are interested.

Great, will read through the article and play around to see what the option does on my brothers Nikon D60 (I've been playing around with his camera before deciding whether to splash out). Great pictures, looked at them briefly, will look at them properly tonight. Thanks.

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