PC vs. MAC - Projected Image Comparison

[JEB]

Hi,

Leaving aside all other pros and cons of either platform does anybody have any personal experience or views as to whether either platform provides a better PROJECTED image? Assuming the same file and projector is used.

I would be very interested in any constructive comments.

Regards

John

[JEB]

Hi,

Leaving aside all other pros and cons of either platform does anybody have any personal experience or views as to whether either platform provides a better PROJECTED image? Assuming the same file and projector is used.

I would be very interested in any constructive comments.

Regards

John

Hi,

Given the utter silence since making this post I fear it was as daft a question as I thought. My reason for asking is that when I come to replace my present PC I would like to be confident that I am making the correct decision in NOT going for a Mac. Personally I have ruled out all other perceived benefits of moving to Mac. If I were convinced that I would get a improved projected image then I would think again. So if there are any technocrats out there who can persuade me then - "SPEAK UP OR FOREVER HOLD THY PEACE"

Regards

John

[JRR]

John:

IMHO, both are essentially correct and the same IF properly calibrated

A properly done calibration is only good if the computer/projector combination are being used in the same lighting conditions as the were present when the calibration was done. A change in the the screen, or the ambient light, or the age of the projector bulb, even the wall colours, etc may affect the appearence of the projected image. Obviously substitute a different computer to the same projector will not give you an accurate display without a new calibration with the new computer, either a MAC or a PC)

I am a PC user, but I was part of a recent e-mail discussion recently that dealt with a question close to yours.

One person reported that their individual images, to be printed, looked very murky on a MAC vs a PC. Another person reported using an uncalibrated projector/Mac combination did not display their as well as an uncalibrated PC/same projector combination.

To my limited knowledge it sounded more like a calibration issue in terms of the projector issue. Simply put the PC default output worked better than the MAC. But note I said NEITHER had been calibrated.

Here is a note we received from a MAC user in response to the issue:

There are a number of issues at play.

1 - Macs and PCs have historically used a different gamma see here which means that (without adjustment) images can appear darker on a Mac or washed out on a PC. With the last release of the Mac OS this year, the default Mac has been changed to 2.2, the same as PCs. Over the next year as most Mac users upgrade this issue will disappear.

2 - Color management is handled differently. On the Mac it is at the operating system level, with its management encoded in any images or presentations developed (this is the reason every pre-press group uses Macs or colorsync on the PC). The color management is futher complicated by RGB, sRGB, Adobe RGB ...

3 - Projectors have a very limited color space compared to most displays, and those color spaces vary as the projector warms up, and as the bulb ages.

4 - DVI vs VGA connections make a difference on how the digital to analog conversion is done.

Doing a calibration for the Mac on any display is relatively straight forward (for non pre press requirements) since the OS allows for software calibration.

Looking at images or videos prepared on the Mac on the PC or vice versa is more problematic, though the issue is more viewing the images on multiple computers. Apple has a built in color management profiles that can be imbedded in photos or videos, and are readably by Safari or Chrome. There is no equivalent on the PC. An sRGB color space limits the problem, though the difference in calibration of monitors can still make a significant difference.

The closest solution for stills is sRGB because it is the smallest color space.

In our case there was a possibility of having MAC and PC prepared shows presented at the same venue. The advice for that was:

For a presentation that is going to use both a Mac and PC the steps would be:

- calibrate the projector for the PC since it requires adjusting the projector,

- then do the software calibration on the Mac leaving the projector unchanged.

This should give more than reasonable results on both computers, up to the capabilities of the projector. The Mac and PC should use two different connections to the projector in order to ensure that the calibrations are not changed.

[Guest Yachtsman1]

Hi John

Being as you didn't get any replies, I'll give you my two penneth.

From what I understand, Mac is used widely in the graphics/publishing/art sector of business I am told because colour & resolution are handled better than a PC system, whether this is paseed on to a projected image I wouldn't know. Additionally Mac has only recently become compatable with PTE as you know so I would suspect Mac Pte users are in the minority, which is probably why your query had no response. I could guess that a projected image would be no different from either a Mac or PC but it would only be a guess. Maybe a check of a MAC based forum would throw some light on the matter.

At least you got one reply.

Regards Eric

Yachtsman1

[JEB]

Hi Jim, Yachtsman1,

Thank you both for your replies.

It looks like I should give this issue a little more thought.

As I understand your very detailed reply Jim calibration is at the center of this. What has brought this about is that twice recently I have been impressed by projected AV shows from a Macbook, as opposed to shows from a PC. In both cases the same projector was used though the images were different. The projector and PC have not been calibrated recently and as far as I am aware the Macbook used was not specially calibrated in any way. If I am understanding the explanation given correctly then a Mac with no adjustments made is more likely to be accurate than a PC that is due calibration. Given the time factor in calibrating a PC there could be, on the face of it, an advantage in using a Mac?

As my principle objective is for producing shows for projection rather than viewing on screen or TV this is an important issue for me.

All of this research is being carried out as an insurance against the day that my present trusty laptop decides it has had enough and I have to replace it in short notice.

Thanks again to you both for your comments.

John

[JRR]

...

If I am understanding the explanation given correctly then a Mac with no adjustments made is more likely to be accurate than a PC that is due calibration. Given the time factor in calibrating a PC there could be, on the face of it, an advantage in using a Mac?

...

John

John:

In my limited knowledge of MACs I wouldn't agree with your conclusion.

It simply is the luck of the draw if you are going with an uncalibrated, or old calibration, PC or MAC. Would also depend on the settings on the projector.

But I agree calibrating a MAC is easier compared to a PC.

[Ed Overstreet]

I was the person who started the discussion thread on our club forum that JRR is referring to, and just to clarify a bit --

What sparked my post was my discovery that cross-platform use of a JPG produced from a calibrated PC monitor can create serious problems if you take the JPG to a service bureau to get a print made, when that service bureau uses a Mac system to do the printing. My PC monitor is calibrated, but at gamma 2.2, and my service bureau's monitor and system (Mac) is also calibrated, but at gamma 1.8. Neither the monitor display nor the print from the service bureau looks even close to what I get on my monitor, and the only way I could get a proper match was when the service bureau manager allowed me to adjust my JPGs on his Mac system in Photoshop, that worked.

As far as I know the service bureau is using gamma 1.8 on his Mac, whether out of habit or because most of his Mac users do the same, I don't know. (When I first started discussions with the service bureau, it never occurred to me that he'd be doing the printing on a Mac, and when he mentioned he would the penny didn't drop until he ran some proofs -- see below -- and I realized there was a big problem and finally figured out it had to be the gamma used in calibration.)

I agree with JRR, as long as you calibrate either a Mac or a PC then images should look the same, IF and ONLY IF the calibrations are to the same gamma as was used to adjust the images. If you have an AV show full of images that were adjusted on a system calibrated to gamma 2.2 and then try to display that show on a system that is calibrated for gamma 1.8 instead of 2.2, you're likely going to be in for a very rude surprise, if my experience with my service bureau is anything to go by. (On his system my images were horribly contrasty, highlights blown and shadows blocked where on my system no highlights are blown and the shadows have lots of detail. And the problem was both on his monitor and on the prints he produced from Adobe Illustrator - this was for a book I'm self-publishing with my wife - and yes his monitor was calibrated with his printer, if you put the print next to his monitor they looked almost identical and identically awful and not how I'd adjusted them on my system.)

Be careful and don't take anyone else's word for what will happen if you display cross-platform, preview the results on the other system in question and make sure it's going to work before you embarass yourself in front of an audience (or spend a lot of money on a print run that produces prints you can't live with, thank God I insisted on seeing proof pages first ...)

And if I were ever thinking of switching from PC to Mac, or even contemplating whether it would be worth it, I'd take a bunch of PTE shows and JPGs that I created on my PC and demand that the salesperson let me view these on a 2.2-gamma-calibrated Mac before I'd even think of shelling out the money. I don't care what any engineer or salesperson says about how it wouldn't be a problem, I won't believe it unless I can see it with my own eyes.

I confess I've never tried viewing or projecting one of my PTE shows on a gamma-1.8-calibrated Mac, but given my experience just mentioned I would be VERY gun-shy of doing that and would not want to let someone display one of my shows on any Mac calibrated to any gamma until I've previewed it myself ...

I'm not from Missouri, but I grew up near there, and "show me" is my motto to this day.

[JEB]

Hi,

Well, this is where I really expose my ignorance and bad practice.

I am NOT in the practice of calibrating my PC or projector frequently enough - unless once every 18 months is enough! (sick joke!)

So from that starting point let me add that when I have calibrated in the past I have used a Spider system going through that long process in the dark and not really noticing a great deal of difference at the end of the process to be honest. That said I accept that I should take this procedure more seriously as I am obviously not getting the results that are possible.

It being as I have said, some time since I have gone through this process, I can't recall there being a particular reference to gamma, specifically the ability to set it to 2.2 or 1.8 so I will have to look at this again. I assume that setting gamma to both the projector and the PC is also possible and necessary. I have a Canon SX50 and my club has a more recent Canon so presumably if the club's projector and PC are set to 2.2 and my PC laptop or any other PC or Mac laptop are set to 2.2 and the images were prepared on these computers then we are all singing from the same hymn sheet.

Or is that too simple?

I accept the points made regarding bulb life and surface etc.

I appreciate your input.

Regards

John

[JRR]

John:

I am no expert in all this, I have just had some practical experience as compared to theoretical.

I have never calibrated my own projector with my laptop. Simply because we use them in constantly changing conditions. If I am unsure about what I am seeing on the screen at anytime, I have a test image that I can throw up on the screen and do a contrast/brightness adjustment in a few seconds.

At our Photo Club though we used did a thorough calibration monthly.

I don't recall a gamma setting option in the Spyder2Pro calibration our Club uses (maybe Ed Overstreet might have a better memory) but I am sure I saw the gamma options when the MAC was being calibrated.

Just because the gamma might be set to 2.2 on all computers using the same projector, doesn't mean they will automatically be calibrated. You would still need to do a calibration.

Having said all that, in all the calibrations I have done, the difference between the before and after has been marginal at least.

You will never satisfy everyone with a new calibration, particularly at a Photo Club, as everyone expects their images to look EXACTLY the same at home as at the Club. It will rarely happen for many reasons - incorrect calibrations, old calibrations, difference in reflective screen vs LCD vs CRT etc etc

[Ed Overstreet]

Hi,

Well, this is where I really expose my ignorance and bad practice.

I am NOT in the practice of calibrating my PC or projector frequently enough - unless once every 18 months is enough! (sick joke!)

I assume that setting gamma to both the projector and the PC is also possible and necessary. I have a Canon SX50 and my club has a more recent Canon so presumably if the club's projector and PC are set to 2.2 and my PC laptop or any other PC or Mac laptop are set to 2.2 and the images were prepared on these computers then we are all singing from the same hymn sheet.

Or is that too simple?

I accept the points made regarding bulb life and surface etc.

I appreciate your input.

Regards

John

Hi John.

If both computers, monitor and projector all were calibrated to the same gamma, then yes as I understand it they all will be singing from the same page -- though if one were a Mac and the other a PC, I'd really want to see this with my own eyes, being the paranoid person that I am (many times burned by techhies in the past, many times shy ...)

In terms of where you set the gamma, I forget where it is on the projector. If you're using a ColorVision Spyder for calibration, as I do, then at least with the software that comes with Spyder2Pro the place where you set the gamma is on the third screen page (which you get to by clicking the Next button a couple of times), where a display tells you what gamma is the current default for the software and gives you a radio-button choice between "continue with these settings" or "change these settings." If you don't like any of the settings, click the second radio button then next and the software will let you change them.

After completing the calibration the software lets you toggle between a "before" and "after" view of a standard calibration image; on every monitor I've calibrated there is a very noticeable difference. However if you have an older version of Spyder you may not have this option in the software, alas. Spyder2Pro is worth the upgrade in that case, because it can be used to calibrate CRT and LCD monitors (you have to tell it which) and also can be used to calibrate a projector (equally necessary and different from calibrating a monitor). Though the before/after display is obviously more of the "nice to have" not "got to have" variety of feature ...

I re-calibrate my monitor roughly once a month, though maybe that's overkill. I also take advantage of the option to calibrate taking into account ambient room light, since I work in a room with a west-facing window. I have up to five different calibrations available at any one time: one for a sunny morning, one for a cloudy morning, one for sunny afternoon, one for a cloudy afternoon, and one for night-time (which is when I actually do more than half my editing) when it's dark outside and I'm using the same room lighting all the time. I change the calibration monthly, or would do at least every season, because at our latitude and climate here in Ottawa, the amount and colour-temperature of the light coming through my window in daytime varies quite a lot between the seasons and also depending on whether there's snow on the ground outside. However if you work in a room like our photo club's "digital darkroom" where there are no windows and the door is kept closed, the only light is from the overhead lighting, then you only need one calibration -- though as a monitor ages you need to update the calibration, because the image likely will dim and probably drift toward the red end of the spectrum over time, at least that's what seemed to happen to my now-defunct CRT monitor.

Hope this helps.

PS added later, hope you spot it ... Before I calibrate any monitor or projector, the first thing I do is go to Windows Display Properties (either through the Control Panel or right-click on the desktop, go to properties, go to Advanced tab>Color Management) and disable whatever calibration profile is currently active on the system, THEN open the calibration software. I don't know whether this is technically necessary, but it can't hurt, and it means "starting from a blank page." Also before starting the calibration, reset the display device's Contrast and Brightness settings to neutral or 50% (depending on the device's menu choices) as this generally makes it easier and quicker to calibrate the grey scale. And, very importantly, when you save the calibration profile when prompted, include in the profile file name the display device (if you have more than one), the room (if it's a projector used in more than one room), the screen (if there's more than one choice), the ambient light (sunny morning/whatever in my case), the brightness and contrast settings you ended up with after calibrating the device, and the date. Whenever changing a profile because of an ambient light change, different room, or whatever, always note the brightness and contrast settings and reset the display device to match what's in the profile name. Especially if other people use the display device, as always happens with club projectors Murphy's Law reigns supreme ... assume nothing, always check everything ...

PPS sorry to add another thing I forgot, but I'm juggling several pins at the same time this afternoon Another choice you have to make when calibrating is the colour temperature to use for the "white point." On my LCD monitor there are three pre-sets: sRGB (5000K or something??), 6500K and 9300K. I always use 6500K since a) that seems to be pretty commonly used, though as in any technical matter there are always raging arguments about this which I tend to ignore, and that's very close to the "native" colour temperature of the club's Canon SX50 which I think is 6700K or something like that, it's in the manual somewhere. Some folks used to argue for 9300K since a lot of older monitors shipped at that default and the assumption was that most people who view websites don't calibrate their monitors and were using that temperature, but I find it gives a very cold image that I don't like. On my CRT monitor I sometimes tried 5500K but I found it looked overly warm and didn't like that, either. 6500K seems to work well for the various print jobs I've had done, at two different service bureaux to date, so I'm comfortable with it. (If in doubt, ask your contact at the service bureau which temperature they use, when you're having them do prints. If the contact doesn't know what the question means, find yourself another service bureau, fast ...) I always add the colour temp to the file name for the colour profile, though I almost never change it from 6500K...

[JEB]

Well,

Thank you all, particularly you Ed for taking so much time to record your thoughts.

It is up to me now to put all of this into action.

As it happens a few of us at our club have been putting off getting to grips with this for some time. I am presently printing all of the replies out to bring with me tonight. I have a good idea what will be happening in the near future.

Thanks again to you all.

Regards

John

[JRR]

John:

I sent you a private message through the PTE forum message service.