Are there any important considerations for stock photos?

Question

I have quite a few photos, some of which I consider to be particularly good. I've been thinking of putting some up on stock photo sites (that's another discussion), but have been wondering about image quality.

Are there any important aspects a photo should have before being put up on a stock site? I'm thinking of subject, composition, colour, and clarity, but what else?

Asked by Grant Palin

Answer

One thing that's not technical but more subjective is how "sellable" the image is. The world has so many photos of sunsets, women sitting at desks on the phone, and nice forest landscapes that you will want to choose subjects that are something a little different in order to stand out amongst the crowd.

Yes, technical correctness will be needed, but to really get noticed on a stock site (and in some cases, to get accepted) you need images that are timely and can't be found in hundreds of other locations.

Answered by ahockley

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How would one find out what sorts of stock photos are in demand?

Question

I know that stock photography is a very challenging market right now but it seems that certain subjects and themes do well. How would one know what sorts of stock photos are in demand versus what subjects are overshot and likely not to pay well?

(please, no doom-and-gloom-of-stock rants...)

Asked by ahockley

Answer

The microstock sites often provide charts of the most popular images or tags. Some examples:

• http://submit.shutterstock.com/top50.mhtml
• http://www.istockphoto.com/participate/contributor-lounge/trends

There's also highlighted images from agencies:

• http://www.alamy.com/showcase/latestimagery.asp

Some sites even explicitly say what they are looking for:

• http://www.istockphoto.com/help/sell-stock/training-manuals/photography/quality-standards-what-were-looking-for

The only issue with popular lists is that it shows what's popular. It might be more profitable to find a niche that isn't well represented - e.g. your local area, or somewhere with a good view that only you have access to, or your profession.

Original or very good quality seasonal images can be more popular than you might think, as long as you upload them a few months before the season - e.g. Christmas related images in October.

Answered by Maynard Case

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Using carbon-fiber tripods in cold weather: safe temperatures, precautions, and effects of failure

Question

I'm considering buying Manfrotto 055CXPRO3 carbon-fiber tripod legs with a Manfrotto 498RC2 ball head, but I've read that carbon fiber can break at low temperatures.

• How cold an environment can I safely use a carbon-fiber tripod in, and what precautions should I take?
• What would happen in the event the carbon fiber fails? Is there a significant health or safety hazard beyond equipment damage?

Asked by DragonLord

Answer

Carbon fiber can take quite a hell of a beating, both in terms of environment (water, sand, snow) and temperature. I've heard a lot of people discussing or complaining about how carbon fiber is susceptible to extreme cold, however I think most of it is hearsay and speculation.

There are only a couple times when I've read something regarding carbon fiber being fragile at cold temperatures...but the use of the word "cold" was always lacking. You would need to spend a night out on the frozen ice pack of the most northern reaches of Alaska during the heart of winter (which is actually what all of the verifiable accounts of broken carbon fiber 'pod legs I've read described...usually in relation to photographing the auroras) to actually experience cold enough temperatures for it to actually pose a serious problem. Most carbon fiber tripods these days are multi-layered, weaved or braided, and resin-reinforced. In the average case for cold, you may crack a layer if you slammed a leg with enough force, but it would take a pretty extreme freeze, well, well below zero, to run the risk of actually cracking a leg all the way through or shattering one completely.

As for precautions, if you are using your tripod at -20 or below, you need to make sure you don't slam it or strike it with anything hard. Dropping your pack or bag on hard snow pack or ice with the pod strapped to the outside is a sure way to crack or shatter it at extreme temps. You can crack a leg by pulling it too hard when setting it up, so you need to be careful with that as well. Section releases can ice up, and wrenching them too hard at cold temperatures may cause cracking, so its best to ease into it. Better yet, extend one or two of the sections before you get out into the extreme cold, and only extend the last sections if you absolutely have to (most of the articles I've read on aurora photography seem to indicate that you'll probably be sitting in a chair anyway, so full extension is often not required in the first place.) Once set up, you'll want to make sure you don't slam any of the legs with anything hard...such as the camera, any other gear, a flashlight, etc.

If for whatever reason you DID shatter a leg, I don't know of any specific health hazards. I've always heard carbon fiber was a pretty stable, safe, environmentally friendly product, so I wouldn't worry about that. Its unlikely it would break cleanly, especially if you have a layered product like a tripod leg. Its likely to leave a rough edge, so I would be aware of that and make sure you don't scrape your stab yourself with any broken ends.

Answered by jrista

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How to compare the focal length of a 50mm prime lens with the default lens of a point and shoot camera?

Question

To imagine the 50mm focal length of a prime lens 1.4F, can I simply zoom the lens of my point and shoot camera up to 50mm?

Will both the focal lengths be same?

Any other way to imagine the focal length 50mm of prime lens 1.4F when what you only have is a point and shoot camera with 70mm max zoom?

Asked by Anisha Kaul

Answer

If your point-and-shoot has the typical 1/2.3" format sensor and you are trying to compare it to a 50mm lens on a cropped-sensor DSLR (in your case, a Nikon, if I recall correctly), then there's a little bit of math involved.

The compact's sensor has a 3:4 aspect ratio. It measures 6.16mm by 4.62mm, with a diagonal of 7.70mm.

The Nikon DX sensor has an aspect ratio of 2:3 and measures 23.6mm by 15.8mm. That would give a diagonal of 28.4mm.

It's normal to compare lenses based on the diagonal of the negative/sensor. I don't like that approach, though, since the aspect ratio is different. It's best to compare images with the same aspect ratio, and in the case of both of these sensor formats, the full length of the short side of the sensor will be used when an image is printed in a 4:5 aspect ratio. That is, an 8x10 picture made with either camera would involve cropping the longer dimension. So it's safe to compare just the shorter dimension of each camera/lens combination.

The 50mm lens on the Nikon is about 3.165 times the length of the shorter side (the height when the camera is held horizontally). That means that in order to get the "same" 8X10 from your compact camera, the lens would have to be set to 3.165 times the shorter side of its sensor, or about 14.6mm.

If your compact has a different-sized sensor, the math will still hold. Find out what format of sensor it uses, then multiply the shorter side of the sensor by 3.165 to find out how far out the lens needs to be zoomed to approximate the 50mm lens. Do note, though, that the field of view for our hypothetical 8X10 print is the only thing the two cameras will have in common.

Or, if you want to do it without the math, my rather standard 8-1/2" (about 21.5cm) tall head will completely, but just, fill the frame of a Nikon DX in "landscape" orientation from the top of my bald pate to the bottom of my chin using a 50mm lens from almost exactly three feet away. So a volunteer or a ruler three feet (90cm) away or a mirror 18 inches (45cm) away will be enough to show you how far to zoom.

Answered by Stan Rogers

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“One size fits all lens” for Sony and Nikon, or a Nikon lens plus adapter?

Question

I've been taking photos with the supplied kit lens with my Sony Alpha 200 for the last couple of years. I'm looking at changing the body to a Nikon D7000 at some point in the future and I'm also looking at getting a 50mm prime lens.

My question is, which lens can I buy that would fit a Sony Alpha 200 and also a Nikon D7000? Should I get a Nikon lens and a lens adapter or is there some form of 'one-size-fits-all' lens?

Asked by Anish Patel

Answer

There is no such thing as a universal lens. The shape of the connection, position of the contacts (and electric protocol too), distance between the connector and sensor are all different.

There are adapters to bridge the gap which are mostly used for legacy lenses. The reason is that with those adapters you will lose most communication between the body and lens, so you have to focus manual, probably have to set aperture manually and sometimes will have to use the camera in Manual mode only (no metering).

There two extremely important points to note above: - If the lens you use (such as ALL kit lenses for DSLRs) does NOT have an aperture ring, you will only be able to shoot at one aperture (usually either the smallest or the largest). - If you adapt a lens who is supposed to sit closer to sensor, it will be be able to focus very far and you will almost certainly lose infinity focus.

Given all this and my understanding that your lens investment is minimal, I would recommend simply buying the lenses you need for your new camera.

Answered by Itai

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How can multiple exposure be achieved with a digital camera?

Question

When using a film camera, it’s possible to create photographs that are the result of multiple exposures, by not winding the film on before taking the next shot. Is there a way of achieving the same result with a digital camera?

I’d like to be able to take multiple incremental shots and then either have them automatically combined in camera, or in post processing.

I know I can create a similar effect by using a long exposure, like the one below (shot with 10 second exposure), but this is quite limiting in what can be achieved and makes composition quite difficult.

Asked by forsvarir

Answer

Note that this is called multiple exposures, not incremental.

A good number of digital cameras of all sizes do this: Most Pentax DSLRs (K-5, K-7, K20D, K10D, K-r, K-x), the Pentax Q, all third generation Olympus ILCs (E-P3, E-PL3, E-PM1) plus the OM-D E-5, most mid-to-high end Nikon DSLRs (D300S, D700, D3X, D3S), the Canon 1D X, a number of Fuji ultra-zooms (like the S9000) and the Olympus ZX-1 which is the smallest camera to have this feature.

Honestly, doing this in software is extremely easy and much more flexible by using Photoshop layers (or equivalent) with various blending operators. The only time one would do it in camera is if you absolutely need to get the alignment blending exactly a certain way. This will be tedious on any camera which is not a Fuji because they are the only ones which let you undo the previous step in case it does not appear as desired.

Answered by Itai

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What are the best and worst diffuser materials for DIY softbox/light tent?

Question

There are hundreds of web sites with tips of building a DYI soft box or light tent, and it looks like people are using almost anything as the diffuser material, from white plastic bags to old t-shirts.

If I take a common household item that I might want to try to use as a diffuser, it is fairly easy to see how much it scatters light, how much it reflects light, etc. However, it is a lot more tricky to estimate how it affects the colours: if there is a slight colour cast, or if the diffuser blocks certain wavelengths. As we know, what looks like white to a human eye is not necessarily perfectly white...

Therefore I would like to know: which materials are good as diffusers and which materials should I avoid? Are there any useful rules of thumb in selecting the diffuser (besides experimenting with various materials)?

In particular, if I wanted to actually invest $5 in a diffuser, what kind of material should I buy? I would prefer a paper-like material, something that resembles wax paper or tracing paper.

Asked by Jukka Suomela

Answer

The best diffuser I ever found was two-side-matte drafting film (either mylar or acetate). You get excellent diffusion and minimal light loss. The only problems with it are:

• it burnishes, so you have to be careful with pressure and rubs when transporting or storing it; and

• it's relatively stiff, so there are fewer options when constructing things out of it.

Another good material is frosted window film -- the sort of thing you'd use for privacy. You actually get a couple of different options here: frosted film gives very good, flat diffusion; while something with a micro-beaded texture gives a gradual radial fall-off with hotter highlights. This stuff is available by the foot at any home center.

If you want something that can be thrown casually into a bag without too many consequences, then a translucent white plastic shower curtain is a cheap option. It may be the last thing you want to have hanging in your bathroom, but it's good for photography.

I'd give muslins (beedsheets and so forth) a pass for most applications. Excellent diffusion, but they tend to block too much light. There's not a lot of point saving a couple of bucks on diffusers if you need to make up for it with tens or hundreds worth of more expensive lighting. That being said, it may be worth a trip to a fabric store to buy a couple of yards/metres of a white synthetic -- often they are woven of transparent yarns, and rely on the thread size/texture and weave density to give them the appearance of whiteness. Take a flashlight with you. You need to hit the right store at the right time of year, but you can often pick up something that's just as good as the expensive commercial products at a real bargain price in widths you can't get with paper products or drafting film. But if the fabric is in season or en vogue, it'll be on the pricey side.

Answered by Stan Rogers

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