Many of us have blind spots when it comes to recognizing just how many ways to chimp there are. If you just need to check sharpness, composition and histogram while you are on the go try this lateral thinking exercise: Can I make better use of the preview screen? Can I use it so well that I no longer need to pack a laptop on my go-trips during the day? Now we have to make a distinction here: packing a laptop while you are on the tour, and packing a laptop so you can use it at the hotel. We are stepping a step back here to look at how we photograph so that we can make a stronger and smarter distinction about how to pack.
If you can answer the two questions amiably with workable solutions then you can say to yourself that you no longer have to pack a laptop on the go as long as you have no reason to retouch and email the files while walking on the Great Wall of China.
(If any of the details that follows in this answer is already apparent to you, please no condescension is being implied. I hope it will be of use to the next reader.)
Sharpness (without a laptop)
I think the best way to check for sharpness is being able to zoom in on your photo easily to 1:1 magnification and check for that sharpness in all lighting situations. Even if it's the mid-day sun beaming down on you. It's a common problem with an inexpensive solution, try the HoodLoupe.
The HoodLoupe ensures that you can check all areas of your preview LCD very well in all lighting situations--keeping things contrasty and sharp. You can easily check for sharpness and it is so small you can pack it without buying a photo bag that takes laptops.
The HoodLoupe is X2 super hero in more ways than one. One of the reasons people don't trust their shots is that the optical view finder always shows what the world looks like when the lens's aperture is fully open. The reason this is so is to keep the optical viewfinder nice and bright. Some camera manufacturers accomodate for this with a Depth of Field preview button so that you can actually see just what is blurry or sharp from the Depth of Field to the beyond. If you have such a button great, but you'll see that these buttons greatly dim down the view. Most modern cameras accomodate this by brightening up the scene when you view it with the Preview LCD through the magic of boosting the light in Live View. So that's great. You get to see the true depth of field affecting your composition and you also get to see it nice and bright. So a HoodLoupe gives you an incentive to compose using Live View, getting sharper and better thought-out pictures when normally you would have resorted to using the optical view-finder.
Getting the focus and depth of field control perfect before you even depress the shutter is huge. It means less bad shots to go through during review and you know that everything that ought to be sharp is sharp (the 1:1 preview mode in Live View goes very well together with the HoodLoupe) and what should be blurry indeed is. That's the X1 super hero part.
The X2 super hero part comes in in that it's a double whammy when you visit a sunny country on your travels. Not only is the bright light going to make it awful for you check your photos in the internet cafe before you email it after the shoot, it will make it impossible to chimp the photos as you shoot. HoodLoupe makes your chimping and reviewing both functional as long as you trust your preview screen.
Your alternative to this is of course to pack a sheet of black velvet with which to cover your head and the laptop. =)
Sharpness two
Taking the time to shoot with user-selected AF points is the second best way to ensure you have a sharp photo. This greatly lessens the need to chimp or to check with your laptop. Most beginners understand that AF points help cameras make exposure and focus decisions but it's important to know that AF points can help you figure out whether you have focus exactly where you want it. AF points are also indispensable to master when you take over the responsibility of focusing (manual-focus) in poor light or when you want to front-/back-/pre-focus.
Knowing how to use the AF points well will solve a whole suite of problems. They will help make up for poor optical viewfinders, delay the need to buy a split focus-screen such as the Katzeye, save you from missing a shot due to excessive chimping and remove much of the anxiety that causes people to want to review their photos with their laptop.
At best you'll just take a few photos as insurance, you won't do it because you are worried about sharpness where it counts. With AF points mastered, you'll only use chimping to ensure that everyone is sharp in a group shot.
Sharpness Three
The third thing that puts the mind at least for well-educated photographers is understanding how to pull out the right photos from their lens after such said lens has been set to their hyperfocal distance. Hyperfocal distance is how you set up your lens so that YOU are in control of the compromise between the sharpness of things at infinity and things in the foreground. As you know landscape photos are typically a bit more interesting if what's in the peripheral is complemented by something in the foreground. Knowing how to keep what's in the foreground as sharp as possible while keeping what's in the distance sharp depends on your understanding of hyperfocal distance. A Hyperfocal distance calculator can be purchased for your smart phone for just a few bucks or you can write down a few likely settings onto some index cards and place the cards in a weather-proof Ziploc bag.
Learn hyperfocal distance! There's a ton of well-written educational material on this topic so I won't repeat it here. Educating yourself on this topic is a huge favor you are doing for yourself. Again, once the decision is made inside your mind, the right photo follows and you will KNOW how much blur and how much sharpness you should get without over-chimping or checking on a laptop.
Reality check (without a laptop)
Get into the habit of checking the hair, wardrobe, and distracting things that fall within the frameline of the photo you are aiming to compose. You'll chimp less later, more importantly, you'll have less photoshop to do. Big win for just a few seconds of eyeballing.
Exposure (without a laptop)
Effective use of the histogram will help you figure out whether you have a problem exposure, whether sections are blown out pretty effectively. Learn to use the RGB histogram and suddenly you will rarely ever pack a laptop for travel photos.
Color (without a laptop)
The more you do imaging at a professional level the more you'll come around to the idea that it is just awful trying to process photos to their most perfect tonal value and ideal hue when you have little or no control over the lighting that lights your laptop's LCD. If this is just travel photos most people will just leave the color work for when you get back home. Or if you are press, you would just email the files back to the Photo Editor at HQ and he/she will assign the color work to a graphics person--knowing you can't do a thing out there in the field. So why bring a colorimeter and a laptop when you can't do all that much with the laptop if there's a big wall size hotel window blinding your LCD?
On the other hand, you CAN get a sense of what amazing color you can bake out of the RAW files by setting the Color Styles in your DSLR. Then whatever you see in the preview is no longer the neutral look of the RAW file, but what you'll likely tune the file to be once you get home. So getting to know how to quickly and accurate set the right white-balance (a bit of a challenge for night-trips around the city, especially with Canons since they have a quirky idea about artificial lit white-balances) and using a hand-tuned Color Style is highly helpful to give you a sense of how likely you can bake your JPEGs just the way you like them once you get home.
Final note
Just some ideas.
I hope this answer entry is interesting since I think there will be equal interest in making your travel fun and fulfilling without carrying the laptop with you during the day trips.
My goal is to help you pack light. Not having to pack a laptop is HUGE on your day-trip. And if I can get you to feel incredibly confident about your photos with just your DSLR preview screen that might mean you don't even have to pack the laptop in your suitcase. Another win. The lighter you pack--the more confident you are about what you just photographed--the more likely you'll travel further and miss less perfects shots. If I can help you pack an iPod Touch instead of a 14" laptop just imagine how much further you can go on your day-trip! Or maybe you can pack some other gear that will make your trip absolutely perfect! Lastly, if you were to lose the bag somehow--you'll have the consolation that the one thing you didn't lose is your laptop and your personal data--that's also comforting.
Hope this has been helpful in those regards.
Back to the conventional solutions that might apply to the question at hand: Think Tank is well-known on-line and off-line for their line of bags that are designed for travellers who want everything to just fit regardless of which airline or safety code they must deal with. I highly recommend saving up for this series since your investment will likely pay back over and over each trip.
