Week 7 / Seachtain 7

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[IMAGE]: Photo in a small kitchen. Open oven on the left (door opens downwards) and a dishwasher and wine rack on the right. There are 12 triangles of light across the image, created with a DIY lightbox. Source: author’s own image. 

This week’s topics are digital photography and photo editing. There’s a lot involved in photography and, depending on the equipment you’re using, there are a lot of things you might need to know in order to get what you want from your image(s).

To begin with, there are three things that are going to decide how your basic image looks:

  1. Aperture: the space in the lens through which your camera takes in light. Aperture is measured in f-stops, with a common number being around f5.6. The smaller the number, the bigger the opening, the more light is being let into your camera. It’s like the iris/pupil in your eye, and automatic aperture will change depending on the amount of light in a given location.
  2. Shutter Speed: how quickly the shutter opens and closes, i.e. the speed at which your photo is taken. This is usually between 1/20 and 1/100 of a second (but can be 1/2000 of a second, or more than a second). This is kind of like how quickly you blink.
  3. ISO: this is the sensitivity of your camera’s sensor (the part that processes the image) to light. This can go from around 100 (low) to up to 32,000 depending on the camera. The lower the number, the less light your sensor will take in – but also the more detail. The bigger the number, the more noise (or grain) you’ll have. The sensor is like the retina/cornea – it takes all the messages from the world and creates an image.

These three elements all work in tandem. If you find you have the perfect exposure, but you want to use a different aperture, then you must change the shutter speed accordingly (and vice versa).

“Focus” isn’t the only thing that decides what parts of an image are crisp;  aperture also plays a big part. If you’ve got a small f-number, like f1.5, a small amount of your image will be in focus (like being shortsighted and taking your glasses off, if you could decide that you could see everything that’s 3 metres away, but nothing that’s closer or further away). With f22, you’ll get somewhere near “infinity focus”, where everything in view is in focus. You need a lot of light to use an f-stop like this, like very bright sunlight.

Shooting on RAW files (like .NEF, .RAW, .CR2) allows you to save a lot more data, and do more in post-processing, than JPEG. The file sizes are huge, but it’s worth it. The below image obviously flies in the face of the rule of thirds. However, the centre of this image needed to be the focal point. This is a blacked out version of what used to be an LGBT graffiti piece in UCD, which was vandalised last summer.

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I usually use Photoshop but I must admit Pixlr is a very good resource, and it’s free. It allows you to use Photoshop documents and maintains layers, so it’s great in an emergency. I can’t open RAW files with it, though. Here are two edits of more detailed shots of the same subject.

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And here’s a short video of the process behind one of the images. I’m not hugely into adding filters to my photographs unless I’m using Instagram, so I kept it pretty simple.

Check out my Flickr account if you like what you see here!


Seachtain 7

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[ÍOMHÁ]: I gcistin beag, tá oighean ar oscailt ar chlé, agus ar dheis tá miasniteoir agus seilf fíona. Tá 12 triantán solais ar fud an ghrianghraif, agus iad déanta le bosca solais. Foinse: an t-údar féin.

Is iad téamaí na seachtaine seo ná an ghrianghrafadóireacht dhigiteach agus eagarthóireacht grianghrafadóireachta. Tá go leor rudaí a bhaineann leis an g-ghrafadóireacht, agus caithfear dul i ngleic leo má tá tú ag iarradh leas a bhaint as do chuid pictiúr.

Ar dtús, tá trí bunphrionsabal a bhaineann le g-ghraif a thógáil:

  1. Oscailt: cé chomh mór is atá an poll trína thagann an solas isteach sa cheamara. Má tá poll beag agat, ní thiocfaidh mórán solais isteach (f18, f22) ach má tá poll mór agat (f.1.2, 1.5) beidh a lán solais in ann buaileadh le do cheamara. Smaoinigh ar do shúile: tá d’intreachán cosúil leis an oscailt seo.
  2. Luas: cé chomh tapa is a thógtar an grianghraf. De ghnáth tá níos lú ná leathshoicind i gceist, ach is féidir é sin a leathnú amach freisin (níos mó ná nóiméad, m.s. an g-ghraf seo thuas). Cosúil le faitheadh na súl.
  3. ISO: uimhir a bhaineann leis an scáileán atá istigh sa cheamara. Baineann uimhir bheag le beagán solas (100, 200) agus baineann na móruimhreacha le roinnt mhaith solais (ó 1,200 suas go dtí 32,000 nó 64,000). Smaoinigh ar an reitine agus an modh ina n-oibríonn sí.

Oibríonn na píosaí sin le chéile. Samhlaigh go gceapann tú go bhfuil an nochtadh iontach ceart agat, ach teastaíonn oscailt eile uait – caithfidh tú an luas a athrú freisin (agus vice versa).

Ní hionann “fócas” agus an íomhá a bheith breá soiléir. Tá baint ollmhór ag an oscailt freisin. Má tá f-uimhir bheag agat (f1.5 cuir i gcás), beidh beagán den phictiúr i bfócas. Tá sé sin cosúil le spéaclaí a bhaint díot agus tú gearr-radharcach; ní bheidh tú in ann ach cúpla rud a fheiceáil i gceart. Téigh anuas chuig f22, agus beidh beagnach gach rud i bhfócas. Ba chóir go mbeidh go leor solais ann chun f-uimhir mar seo a úsáid, m.s. solas láidir na gréine i rith an tSamhraidh.

Má úsáideann tú comhaid RAW (m.s. .NEF, .CR2, .RAW), beidh tú in ann tuilleadh sonraí a fháil agus beidh tú in ann níos mó a dhéanamh agus tú i mbun eagarthóireachta. Bíonn na comhaid an-mhór, ach is fiú é sin a dhéanamh.

Ní ghlacann an íomha seo thíos le ceann de na rialacha is tábhachtaí a bhaineann leis an ng-ghrafadóireacht: riail na dtrianta. Is í sin an chaoi ina gcuirtear ábhar an phictiúir ar thaobh amháin den fráma, seachas é a chur i lár an phictiúr. Uaireanta caithfidh tú an riail seo a chur ar leataobh. Is éard atá ann san íomhá seo thíos ná píosa graifítí LADT a bhíodh in UCD agus a scriosadh an Samhradh seo caite.

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De ghnáth, úsáidim Photoshop ach caithfidh mé a admháil gur clár iontach é Pixlr, agus tá sé saor in aisce. Ligeann sé duit comhaid Photoshop a oscailt, ach ní féidir leat comhaid RAW a úsáid leis. Seo dhá phictiúr a d’eagraigh mé le Pixlr.

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Agus seo daoibh físeán beag den phróiseas a bhí agam agus mé ag úsáid Pixlr. Ní maith liom a bheith ag déanamh an iomarca eagarthóireachta ar mo chuid pictiúr, agus mar sin thóg mé é go bog é!

 

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