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Comment by dylan604 | Hacker News Reader

All Macro photography requires extra light, it's not just anything to do specific to cell phones. That's why there are so many flash rigs designed for this.

Also, the iPhone 13 camera has ridiculously fast lenses[0]:

  Pro 12MP camera system: Telephoto, Wide, and Ultra Wide cameras

  Telephoto: ƒ/2.8 aperture

  Wide: ƒ/1.5 aperture

  Ultra Wide: ƒ/1.8 aperture and 120° field of view

If you search for lenses for "real" cameras with those apertures and focal lengths, you'll find 4 digit price tags for each one.

Sounds like you need some more research into macrophotography

[0]https://www.apple.com/iphone-13-pro/specs/

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Just a meta-comment, but your reply was really good until the last sentence.

> Sounds like you need some more research into macrophotography

That undermined your otherwise very factual rebuttal/clarification because it seems like at best an impossible standard (everybody could always use more research into anything), and at worst a "you don't know as much as me" veiled in professionalism/passive aggressiveness. The interpretation is up to the reader (some of whom will be charitable in their interpretation, others will not).

To be clear I'm not accusing you of "the worst" (I have no idea what was in your heart/mind and I don't presume to guess), I'm executing on a personal goal to try and help elevate conversations through useful/constructive feedback. Also I'm not presuming that this comment/feedback is useful or constructive as it may not be, but I hope that it is because that's my goal.

I support your goal! Maybe there is a way to state this in fewer words more often.

I find that last line perfectly justified.

OP’s post was incredibly dismissive and incorrect but was written as if it was from an expert.

It’s textbook misinformation as far as I am concerned.

It’s not really about being justified, it’s about being gentler with people. We don’t have to jump all over each other, there is another way.

I think OP will live.

When given the choice, choose compassion.

I think the reply was plenty respectful, and the whining to the contrary is just a veiled attempt to derail the conversation.

Should that be the standard we hold ourselves to?

My post was correct and the person who was responding to me is incorrect. I did not mean to sound dismissive -- I intentionally put multiple paragraphs congratulating the artists and praising what can be done with cell phones in order to try to avoid that look. But it is important to realize that these awards are marketing and marketing needs to be interrogated, IMO.

The rebuttal is actually incorrect and suffers from many misconceptions typical in photography. This makes the condescension much worse, because whoever wrote that did not live up to their own standard.

I interpreted the phrase as meaning something more like “when you make claims about the fundamentals of macrophotography with such a confident, authoritative tone, those claims should be backed by more research than you seem to have done.”

I know you think what you're doing is "elevating" conversations, but ... "calling out" people for the slightest bit of negativity is an extremely toxic behavior. Quality discourse requires negativity and fosters a healthy span of tolerance for it. Your interpretation is also very narrow and passive aggressive itself, to me it seems completely neutral that in a case when someone has a strong opinion based on ignorance, you remind them of their ignorance - not just for people reading it but for their own sake.

Disagree. Attack the arguments, not the person.

Why did that person feel the need to attack the poster? What did they gain from it? How did it help the argument?

I don't think there's a single benefit from that line other than to be self-serving statement that says "i know more than you" when their rebuttal did that more effectively while staying on topic.

That was far from a personal attack. A personal attack is when you attack a specific attribute of that person or use this person itself as an argument for something. It is not if a person does something wrong and you say hey person, you shouldn't do that thing.

It really depends on the purposes of the comment.

Direct responses can be intended to educate the person they are responding to, but they can also be intended to warn people around.

Does this person want to get a point across with empathy or do they want to discredit the comment to future readers to avoid the circulation of false information?

ƒ stops need to be adjusted for sensor size [0]. The iPhone 13 Pro cameras all have and equivalent f stop > ƒ/8 [1]

[0]https://photographylife.com/equivalence-also-includes-apertu... [1]https://www.dpreview.com/articles/6780391159/all-apple-iphon...

stops only need to be adjusted for total photons gathered, not for photons per unit square

Yes, and a much smaller sensor will of course gather much less light.

For the same aperture, sure. But you are not going to be shooting macro photos at f1.5 on full frame (for depth of field reasons alone). For real world macro photography you'd typically be stopping down at least to f8 on a full frame camera. At that point the DSLR has a considerably smaller advantage in terms of the total amount of light gathered.

One thing that people often miss is that you can think about all of this just in terms of the absolute diameter of the aperture (not the f number, just the diameter in mm). For a given angle of view, the diameter of the aperture determines how much light you gather. The question is simply whether a photographer using a DSLR is going to be able to use an aperture that is significantly wider (in mm) than the ~4mm aperture of a phone camera. For depth of field reasons, it's unlikely that they will be able to do so.

Why wouldn’t you need to stop down similarly on a phone camera?

Because depth of field depends on focal length as well as f number. Or to put it another way, it depends on the absolute diameter of the aperture, not the ratio of the focal length to the aperture diameter (= the f number).

(Also, of course, you can't stop down on a phone camera as it has a fixed aperture.)

Numerical aperture alone does not tell you anything about the amount of light gathered. The product of aperture and sensor size does. Phone cameras still have much smaller sensors than DSLRs.

Your advice to learn more about photography certainly seems good.

The Hubble Space Telescope has an aperture of a pathetic f/24 [1]. I guess they should just fire an iPhone up there instead, huh.

[1] §5.2.2 in https://asd.gsfc.nasa.gov/archive/hubble/a_pdf/news/SM2-Medi...

> If you search for lenses for "real" cameras with those apertures and focal lengths, you'll find 4 digit price tags for each one.

The aperture is relative to the diameter of the first lens element. So you can’t just compare these values directly.

Sure you can. The f-stop is the ratio of focal length to aperture diameter. A aperture of f/4 means, the aperture is one fourth of the focal length. At the same f-stop, you get the same light density on the sensor surface.

The catch is: a phone has a much smaller sensor, so at the same f-stop, across the whole sensor less light is gathered and consequently, you have a weaker signal.

Wait until you start looking at transmission values...

f-stop doesn't mean much other than the maximum that the aperture for that lens can open.

It doesn't indicate lens or element quality, or aberrations. There's a reason that pixel peeping, gear games, and reviewers are so prevalent in high end photography.

As a simple extension to this, most of my lenses work better a few stops before maximum f-stop.

So, yes, but no.

In practice, light gathering correlates to F-stop quite well on most normal modern lenses, transmission losses are very low. The main exceptions are deliberately apodized lenses, which have considerably transmission losses wide open.

For the rest - yeah, f# is just one of important specifications.

You were talking about the light being gathered by the lens. That is mostly determined by the f-stop. Technically it is the t-stop, but they should be reasonably close together not to make a huge difference. Quite the contrary, as the phone lens has less elements than some modern camera lens designs, the phone might suffer less from the difference than the camera lens.

The aspects you are now referring to are about the lens quality. Yes, I would expect a real camera lens to be much better than the lens of an iPhone. There is no doubt about that. But in the posting I answered to, you spoke about the comparability of aperture values.

Stepping past the arrogance for a second, there’s more to macro photography than f#. A big factor is the working distance to the object. Not only is this important for skittish live subjects, it’s also important for static subjects for the practical reason that the extra distance provides space for proper lighting equipment. A good used Nikon macro lens can be had for less than a grand and a DX SLR body for less than $300. That’s cheaper than the price I paid for my iPhone 13 Pro, which has proven a bit of a disappointment for macro work.

Further, the wider open the lens, the more shallow the depth of field, which is already quite shallow in macro work. Having the space for proper lighting can allow one to stop the lens down and capture more parts of the image in focus. F# is a secondary consideration as macro often works best at f/8 or f/11.

>F# is a secondary consideration as macro often works best at f/8 or f/11.

At typical full frame focal lengths. With the shorter focal length of an iPhone you get much more depth of field for a given aperture.

Good point.

Lens to object distance is still an important issue in practice however.

f-numbers do not have the same meaning across different sized sensors. For example, f/1.5 on the iPhone is equivalent to f/8.2 on a 35mm camera. This is pretty slow by the standards of full frame lenses, and as you can see in my other post, it is not expensive to acquire much better lenses than this that will achieve much better results with less effort.

See the chart on the first page of this article: https://www.dpreview.com/articles/6780391159/all-apple-iphon...

For a detailed explanation of how to compare f-numbers across cameras have a look at this article: https://photographylife.com/equivalence-also-includes-apertu...

F numbers have exactly the same meaning across different sized sensors: the ratio of the focal length to the aperture diameter. The size of the sensor does not even enter into the definition of the f number.

>For example, f/1.5 on the iPhone is equivalent to f/8.2 on a 35mm camera

This is a meaningless statement unless you specify what sort of equivalence you're talking about. I assume you mean to say that they're equivalent in terms of depth of field and in terms of the total amount of light gathered for a given angle of view. This, however, just goes to show that the 35mm camera doesn't have much of an advantage for macro photography. If the 35mm camera has to stop down at least to f8 (which it probably will, to get sufficient depth of field) then it won't gather any more light than the phone.

The basic point here is that for a given angle of view, you can only gather more light than the iPhone if the iPhone has depth of field to spare. Otherwise you can only gather more light than the iPhone by sacrificing depth of field. This is because both the total amount of light gathered (for a given angle of view) and the depth of field (for a given angle of view) are determined by the absolute diameter of the aperture.

f-stops are relative to the size of the glass + sensor. They aren't equivalent to f1.5-2.8 on an APSC or full-frame sensor.

You're telling people to do more research but don't understand how photography in general works.

The speed of the lens is not the main factor. A Micro4/3 lens at f/2 is cheaper than a full frame lens at f/2, which is cheaper than a medium format in turn. The iPhone's sensors are much smaller still than FF.

The lenses on the iPhone are equivalent to some of the cheapest lenses in any given system.

Indeed, a comparable system would be the 10-18mm EF-S plus whatever kit lens you have.

Talking about relative aperture and angle of view at the same time is incredibly misleading. If you want to talk about angle of view, you need to use absolute aperture.

Lenses aren’t that expensive, especially not prime lenses. You get a very decent Canon brand 50mm f/1.8 for $125 new. So you could easily get each of these lenses in the lower hundreds.

https://www.bhphotovideo.com/c/buy/SLR-Camera-Lenses/ci/274/...

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