Preparing an image for canvas printing

The cost of full colour printing on fabric, usually canvas, has plummeted over the last eight or so months with the cost of a 16” x 20” canvas print now around the $55 mark (plus postage); depending where you get it done. Earlier in the year this sized fabric print was around $120 (Australian prices). But, and this is a BIG but, this price is for ‘final supplied’. This means that you have to provide the finished final digital file for printing and that the people doing the printing take no responsibility for colour casts, insufficient resolution, or sharpness in the ‘final’.

So if your picture comes back and people have greenish or over-yellow faces and this was in the final supplied, then don’t ask for your money back. Ditto if you get your picture back and the resolution was so low it looks as grainy as gravel; unless you were going for that look.

So what do you need to do to ensure you are going to provide a useful final?

Note that the following assumes you have an image of sufficient
size and resolution to begin with.

Firstly, check the Web site of the service you are going to use and see what, if any, specific instructions they provide for preparing your final; then consider . . .

You need to ensure that the final is colour correct, or, if you are not going for colour correct (i.e., you are going for sepia or duo-tone or grey scale, etc.) that the colours—when viewed on a trusted near-colour correct screen—are as you intend them to be in the print.

A year or so ago the general advice was to slightly over-saturate the colours for fabric prints however modern inks and fabric printers have improved and over-saturation is generally not required. However check the instructions for the particular service you plan to use and see if they advise that you do this.

You need to ensure that you have sufficient resolution built into the final for the size of print you are doing, and this also needs to factor in the viewing distance. The greater the typical viewing distance the lower the resolution can be. For a 16” x 20” print with a typical viewing distance of 1.0 to 1.3 metres I would recommend a minimum resolution of 150 dpi. If your starting image does not permit you to resample to 150 dpi I would recommend strongly against trying to up-sample the image. Unless you know what you are doing then up-sampling (adding pixels where none existed before) almost always provides an unwelcome outcome. It is always better to just go for a lower resolution print—say 130 dpi.

Finally you need to sharpen/un-sharpen*. This is a little tricky and also subject to personal preferences and the subject. Some subjects are better printed soft. Others need to be printed hard/sharp. It is difficult to advise on sharpening/un-sharpening but the general advice is to sharpen more than you think you should when printing on fabric.

One note on un-sharpening. You only ever do this when you have completely finished resizing/re-sampling the image.

Actually there is one more thing you need to consider with fabric printing: What do you want to do with the wrap-around edges? This is called canvas-wrap or gallery-wrap and there are two options. You can include the wrap around edges in your final which means your final will be slightly larger than 16” x 20” (this is called an ‘image border’), or you can usually instruct the print service to simple extend the edges—which means they don’t use part of your final for the edges but they extend the colours of the edges of your final for the wrap-around (this is called a ‘mirror border’). There is a third option some services offer. This is to simply colour the edges using a colour from the print—like blue if there is a lot of blue sky (this is called a ‘colour border’, or for my American readers it’s a ‘color border’).

When you save your final ready I suggest saving it as a PSD or TIFF (no compression) and not as JPG. Saving as a PSD or TIFF will ensure no quality is lost from the file. If you save as a JPG, even at the highest setting, you will lose IQ (image quality) information from the picture. However this will depend on what file formats your printing service supports, but seriously, if they don’t support PSD and TIFF then I would be wondering just how good they are.

Saved as an uncompressed TIFF or a PSD file a 16” x 20” image at 150 dpi is going to be about a 20MB file. Saved as the highest quality JPG file the file size is 6MB.

All sound too hard? Alternatively, if you are using a ‘local’ service, you can sit down with a consultant and they will work through this with you on their computer. But this service is generally (almost always) not free. Also, and I shouldn’t say this (but it’s true), some of these consultants are not as knowledgeable as they should be about what they are doing.

You can also Google the Web for more hints and tips on preparing a fabric final.

I am about to try a couple of fabric prints. I will let you know how I get on.


* Sharpening of colour images actually requires un-sharpening. Confusing I know, but such is life.

Misty afternoon pictures of Kalamunda

I went out this afternoon and took some misty ‘up in the clouds’ pictures of Kalamunda. After all the Pentax K-3 is supposed to be water proof so the very fine drizzle ‘should’ not affect it. Unfortunately I am not water proof and I did get a little damp, but such is the life of a dedicated photographer.

Kalamunda is up in the hills to the east of Perth and when the clouds are low they sort of skim over the village as they pass over the hills.

These pictures were taken at 3:00 p.m.

The first was taking partially along the path that weaves its way through the park. This shot was taken so that the rubbish bins on the left and the life-sized chess game board on the right were not in the frame.

I like the almost solid black look of the tree trunks on those trees on the left. This is obviously helped by the fact that they are damp which is making them look more black than they probably normally do.


This next shot is from the entrance to Stirk Park but looking up towards the village. You can get a better feeling for the misty low hanging clouds in this shot. Notice also the water flowing from the gumnut centre-piece in the traffic round-a-bout.


StirkPark01-Small-650yThis final shot is another one taken in Stirk Park. While it is primarily of the tree in the foreground with the lichen growing on it, I was also trying to pick up the deciduous poplar trees in the background o the left—at least I think that’s what they are called.

All of these pictures were taken at 800 ISO and they were not post processed for digital noise.

As usual each picture links to a much larger and higher resolution version in SmugMug.

It continues to amaze me how good digital cameras and lenses have become and I only have a half-frame camera with a pretty average lens.


End of the compact camera—good for the half-frame market?

It was bound to happen. It was only a matter of time. I notice that a number of camera sites, including the well respected DP Review site, are now writing about the end of the compact camera.

I have done a couple of posts in the past about how camera phones were gradually taking over the market space of the compact camera. I posted “Compact camera sales are plummeting” (here) and “Is this the end of the compact camera” (here).

Well it seems like mid-2014 will be written into the annals as the official death of the compact camera. The big camera manufacturers are all cutting back on their compact camera ranges and there have been no significant new model releases in twelve months.

Camera technology advances in mobile phone cameras like the amazing Nokia 1020 PureView, theNokia 930 PureView, the Samsung S5, the LG G3, the Samsung K-zoom (the only mobile phone with an optical zoom lens camera built in), and possibly the new Apple iPhone 6 Plus—although we are yet to see if this camera is a good as the Apple hype.

So what do camera manufacturers do when a whole camera sales market segment dies?

They shift their focus to areas where the serious takers of pictures will still spend extra money to take better photographs—the half-frame market.

My prediction is that we will start to see more innovation and a lowering of prices in the half-frame/APS-C market segment as Nikon, Canon, Sony, Fuji, Ricoh/Pentax, Olympus, and others try to chisel of more of this market for themselves to offset the loss of sales in the compact market.


To zoom or not to zoom—the ‘fixed length’ conundrum

This is an age old problem for photographers. Whether to use a zoom lens or a fixed length lens.

With a zoom lens you get the flexibility of being able to easily change the focal length of the lens with a twist of the zoom collar, or for slide zooms by sliding the barrel.

With a fixed length lens you are stuck with the focal length of the lens. The only way of ‘zooming’ in or out is to either change where you are taking the picture from or change lenses.

The problem being that—for any given price bracket—fixed length lenses almost always have the better resolution/image quality.

Just to give you some idea of the ‘average’ difference between a mid-range zoom and a mid-range fixed length lens, in the picture below the test shot on the left is from an 18 – 135 zoom at the 85mm length taken at f8. The shot on right is from a fixed length 85mm lens also at f8.


Now for most folk the difference is nothing they would be concerned about, but for us ‘serious’ takers of pictures with actual cameras (as opposed to a camera phone) the above has been the basis of many millions of hours of discussions over the years.

A mid-range 18 –135mm zoom lens is about $600 and a decent 85mm fixed length lens is about $500. But with the zoom you get to use any focal length from 18mm through to 135mm. It’s like having four or five or more lens but they are all in the one and you don’t have to keep changing lenses to change focal length. So is that worth the loss in image quality? This is the question?

In the ‘old’ days there was no choice. All lenses were fixed length. You had to change lenses to change focal length. This was probably why the interchangeable lens camera was originally invented.

Then along came useful zoom lenses in the early 1960s, and with these first zooms there was still really no choice. If you wanted crisp pictures you had to use fixed length lenses because early zooms were about ten times worse than the example shown above. Back then serious photographers did not even consider using zoom lenses, except maybe for playing around and seeing just how bad the pictures were that they took were.

But with computer designs, modern lens manufacturing, and precision assembly that we have today the zooms are much better. However, price-range for price-range, there is still a difference in image quality. Enough of a difference for really serious professional photographers making their living from taking pictures to stick with fixed length lenses.

Five or six years ago the saying used to be something like “you can’t fix up bad image quality in Photoshop”. But this is not totally true today.

I promise you that the following picture is the same picture as above but I have used Photoshop Elements to firstly apply 10:10 demisting sharpen and then 30 percent of 1.8 pixel sharpening ONLY to the left hand panel. Nothing has been done to the right panel.


Now the zoom lens shot on the left isn’t looking too shabby.

So maybe now, in 2014, there really is no reason to fear the image quality of zooms; certainly not higher end zooms anyway. Although it does mean you need to do some photo-finishing in something like Photoshop Elements but I would expect all serious amateur takers of pictures are doing this anyway.


Gate Series 6: Lotsa locks, old gate but new posts

Yeah, I know. I am posting my gate pictures a bit out of order. First there was series 1 and 2 featuring the derelict Pickering Brook tennis courts, then I jumped to series 5 with the yellow flowers and the bearded gum trees, then back to series 4 with the flame trees, and now to series 6. I haven’t forgotten series 3. Confused? Hopefully I’m not.

This particular gate has caught my eye a few times for a couple of reasons. Firstly the gate itself is old and rusty, and yet the posts are relatively new—probably put up in the last three or four years I would say. But the land owner has purposely re-used this old style and rusting gate in his new fencing.

The other reason it caught my eye was because the property owner has put a couple of old tractors in the field more or less behind the gate.

Thirdly there is a row of what look like white gums just inside the fence.

So I finally actually stopped and took some shots. Over the last three or four weeks I find that I am getting good as this ‘actually stopping’ thing. I hope I can keep it up.


As you can see from the long shadows, this is late in the afternoon. It is about 5:30 p.m. The sun is only about 30 minutes away from setting. Also, just to add to the challenge, I am almost shooting into the sun. It is going down a little to the left.

I am not generally a fan of wide-angle shots but in this shot I have the lens at 24mm hence there is some fish-eye happening; with the support posts looking like they leaning over a bit. I could have removed the fish-eye effect in PSE (Photoshop Elements) but I decided to leave it as it was.

As always, because I might never stop for this gate again, I took a cluster of pictures and I really could not decide which one to be the feature picture.

Following is my other pick for the feature picture.


In this shot (above) I have knelt down and got the old tractor in the background through the gate. I could not move around to the right and get it in the middle of the gate because then I would be shooting directly into the setting sun. You can see light misting already starting to happen in the left of the picture.

IMGP0720-Gate06-LocksThe farmer has three padlocks on this gate. I meant to take a close up of the padlocks but I forgot, so I have had to crop a shot of the padlocks out of the first picture.

It’s easy to see the first two padlocks but there is a third. You can see it behind the bottom padlock.

I think this is a little bit of joke by the property owner. That chain is so old and rusted that a good tug on it would likely break it apart. Also I am not sure that one of those locks is even doing anything. The hasp of the bottom padlock only loops through the hasp of the lock behind it. This doesn’t actually achieve any ‘locking’—so to speak.

The final picture in this series is a shot of the two tractors. Well, really a shot of the first tractor with the second tractor in the background.

This should also captures some of the white gums.

For this shot I braced myself on one of the fence posts and wound the zoom out to 78mm. I have also engaged Pentax’s awesome anti-shake mechanism.


I would loved to have been able to go into the property and take close up pictures of these two old tractors but I had to be satisfied with shooting from the fence. I have to say I am pretty happy with the performance of the lens.

Clicking any of the three the main pictures will open a 1920x1200 version from SmugMug, and seriously, to really ‘see’ the pictures you need to see the larger images from SmugMug.

For those that like the forensics here are the numbers for the first picture:

  • ISO=400 (400 is the new 100)
  • f11.0
  • SS = 1/200
  • Focal length = 24mm

For the second picture:

  • ISO = 400
  • f11
  • SS = 1/320
  • Focal length = 53mm

The last picture:

  • ISO = 400
  • f11
  • SS = 1/250
  • Focal length = 78mm

All pictures were taken with a Pentax K-3 with the 18 – 135 Pentax ED AL lens.

<< Edit, 7th Sept, 2014 >>

Just thought I would add this panorama style picture showing more of the fence structure. This also shows the row of trees disappearing off the right along the fence line.


Click the picture to see a 3840 x 1200 pixel version from SmugMug.


Gate Series 4: Flame tree gate

I think I just managed to get this shot before the flame trees dropped all their flowers.


When I drove past this going home last Friday these trees had double the number of dazzling red flowers on them. Just two days later on Monday they have lost so many flowers. But it was drizzling rain on Friday. At least this Monday there was a bit of light even though it was still somewhat overcast. But I just could not afford to wait five more days until I came past again for fear of all the flowers having dropped off.

The six flame trees on the left presumably go alongside a road that used to go somewhere? Maybe to a house. You can’t see it in this reduced size picture but in the 1200 pixel version on SmugMug (click the picture to see this bigger version) you can see that there is another gate off in the distance where the flame trees stop.

If it there is a road and it did go to a house then at this stage you can no longer make out a road and nor could I see a house, or any structure, past the other gate at the end of the flame trees.

For anyone wondering why I don’t show all of the gate in the shot there is a dirty great ugly sign wired onto the gate on the left hand side that totally would have ruined it. Well I think so anyway.


Gate Series 5: Gateway to the yellow flowers

This is my fifth gate in my series featuring gates. Anyone paying attention will be saying: “But where are gates for series three and four?”

Very good. Well spotted. I have not posted series three and four yet. I decided to jump to five. I can do that. I write the blogs.

This is a gate on the South-West Highway. On the way to work this morning, completely out of character—instead of zooming past at 110 klms/per/hour—I actually stopped. This was just too stunning to not stop and capture. The way flowers come and go in Western Australia these flowers would likely not be there on my return trip, and almost certainly would not be there next week when I come past. And with the ten o’clock sun shining through the clouds hitting them at the angle it was they were glowing like someone was shining yellow light on them.

But, let’s not forget, this is really a picture of a gate.


This looks like a relatively modern gate and it would appear to be custom made with those curved spikey bit above the top rung shaped in an arch. The circular marker on the left in front of the drum says “Gate 1” so presumably there are other gates, otherwise why put a number on this gate?

It would appear that this gate does not get used much, if at all. There is no evidence on the other side that traffic of any kind ever goes through the gate.

The second picture (below) shows three beautiful bearded gums to the left of the gate. These were obviously planted about the time the gate was installed. Looking at the trees I would say they are about 15 years old (but I am no expert—I could be way out).


As usual you can see 1600 pixel wide versions of the above pictures in SmugMug by clicking on them. The SmugMug pictures will open in a new tab. Please check the larger pictures for a better viewing experience.

Oh! I have no idea what the flowers are.


Sansa the circus cat

These pictures I am posting of Sansa should not be confused with just more pictures of cats on the Web. Let’s face it—no serious blogger posts cat pictures. What these are, obviously, are serious photography related postings.

Okay. Now that I have made that clear . . .

Following is a picture of Sansa (my son’s fiancés kitten) in full flight chasing a sheath of barley seed that the fiancé is waving about.


Her amazing leap was launched from those dig claw marks about a third of the way up and a third of the way in from the right hand side. She is heading across the picture towards the wall and at this point is basically directly above that dense patch of weeds beneath her. She is about a metre off the ground.

If the doesn’t look impressive then consider the following picture, which is a crop taken from the picture above.


That is her launch point in the bottom right. You can also see the small sheath of seeds just above her head; which is what she is trying to snare. She has obviously missed them but you can forgive her for that as the fiancé is waving them about making them a very difficult catch.

Finally here is a further crop taken from the original picture. Don’t you love modern DSLR cameras? Do this with your camera phone …


Look at her front paws. Claws fully exposed. Fingers spread wide for maximum coverage in the air to hook ‘something’. Body at full length. Oh, and on the photography front, even at this crop level and at the speed she would be moving through the air, you can still make out the furry hair on her chest and her whiskers.

Camera: Pentax K-3
Lens: Pentax 18-135 f3.5-5.6 ED AL[IF] DC (I almost never take this lens off these days)
Lighting: The sun, about 15 percent overcast
Winder: High-speed multi frame
F-stop: f8
Shutter: 1/1600
Exposure reading: 80% centre weighted, locked from the fallen tree branch
Negative format: JPG, highest quality setting (RAW too slow for high-speed multi frame)
Focal length: 28mm


Heels or Ring, Cat, Heels? More going on here than it initially seems

This is a relatively clever picture. I found this shot while clicking through 500 pixels looking at amazing pictures other folk are taking and posting.


As it has sexy high heels in it I stopped and gave it a longer look—as would most men. But then I noticed the heels were blurred, which I thought odd for a picture on 500 pixels. After a slightly longer look I decided that the rings were the primary subject as they were in focus; this is not a picture of heels at all.

But then I saw the cat, which I had not spied initially. Obviously the sexy heels get the first attention, and they then somehow draw your attention to the rings, and only then did I spot the cat.

There is something very odd about the cat. It’s in focus and it shouldn’t be.

How can the rings be in focus, the heels out of focus, and the cat in focus? What kind of magical lens or camera is this?

Very clever.

For anyone who has studied photography you would be aware of the PST rule—primary, secondary, tertiary. A primary subject, a secondary interest, and a tertiary (third) element.

When you first see this picture as it flicks up you think—well I did anyway—that the primary is the heels. Then you quickly change your mind and figure the rings are the primary and the heels are the secondary. Finally you see the cat between the heels. So it becomes rings primary, cat secondary, and heels tertiary.

But this still leaves the problem of the cat and the rings being in focus. How can it be?

This could have been achieved in two ways. Maybe he took the shot at a very small aperture like f22 (or smaller) for huge depth-of-field and then blurred the heels out in post processing—unlikely considering the low light available and keeping the cat still for a two second exposure. Or he took two pictures: one with the cat in focus and another with the rings in focus (and possibly no cat in the picture at all). Then using layers overlaid the in-focus rings.

Either way a brilliant bit of work and well lit.

This picture is from 500px. It was taken by Alexey Kalashnikov. Click on the image above to go to 500 pixels and see the full uncropped full resolution picture.


Cluster of Golden Orb spiders: Finally after four years!!

I think I am coming to the conclusion that I am really bad at doing things I want to do.

For four years I have been driving past this sign post just out of Waroona on the right hand side (going towards Bunbury) of the road where there is the large colony of spiders—which I think are Golden Orb spiders. These spiders have been there for the four years I have been going back and forth on that road. During that time they have weathered a couple of severe storms but have rebuilt.

For four years I have been telling myself “one day I am going to actually stop and take some pictures of that” but I have never managed to execute that promise.

Well last week I had to come back from site mid-week to bring my son back (he was heavy with this ‘super’ flu that is going around Perth at the moment) and we actually stopped to photograph this colony of spiders. Technically we overshot it and then we decided to do a U-turn and go back.

Now I will be the first to say there is not much that is artistic about these pictures but, even so, I decided to post them up.

The entire colony is suspended between the road sign and the adjoining fence. Each of the pictures below is only showing a small part of the complete web fabric. I would estimate that there would have been about 50 spiders in the web complex.


The web seems to be constructed between the sign post and the fence in vertical layers. The following picture was taken to try and show these layers. The webs go from the road sign in the foreground to the fence. This would be a distance of about three metres.

Going from left to right, notice how the webs seem to be in vertical layers. So before the post of the road sign there are two clearly defined vertical layers, and you can pick out these layers again coming from the right of the picture.


The following picture is of another part of the colony taken from closer to the fence and looking up. I am trying to give a better idea of how many spiders are sharing this location but it is really tricking to photograph due to the backgrounds.


Finally, following is a close-up of one of the spiders. I understand that the ‘large’ spiders are the females and the much smaller ones—about a quarter down to an eighth of the size—are the males. In the picture below I am assuming that the much smaller spider you can see in the top third slightly off centre to the right is the male.


These pictures were taken with my new K-3, and just to show off a bit, the picture above has been cropped out of the following picture. How amazing is that resolution and detail retention. You can see the hairs on her legs and she has been cropped out of section that is about 1/20th of the frame (as a rough estimate).


I could be wrong about these being golden orb spiders but it is about the closest match I could find on the Internet. If I am wrong then I would like to know what spiders these are so please leave a comment and let me know.

According to Wikipedia the golden orb spider’s venom is not toxic to humans but the bite site is likely to leave a lasting scar. In some people the venom may cause an allergic reaction including muscle cramps.

They look fierce and I certainly don’t fancy be bitten by one.