Ask David: Lenses, Shots Out Of Sequence, Cropping, Lenses to purchase, Megapixels :: Digital Photo Secrets

Ask David: Lenses, Shots Out Of Sequence, Cropping, Lenses to purchase, Megapixels

by David Peterson 3 comments

In my regular Ask David column, I answer common questions from my readers. By answering them here, I hope to help everyone else who might have this problem, and not just the person who asked the question.

Today, we have a bumper edition covering why you shouldn't get a film camera; how shots get out of sequence; why images aren't always cropped correctly; a good set of lenses to purchase; and how many images you can fit onto your memory card.

Today's first question is from Stephen Morris.

I will be traveling soon but am completely lost regarding which camera to get and am worried that at this rate I will end up taking a disposable camera or my phone camera. Financialy I'm constrained which makes it difficult to find a decent camera. I would prefer a digital SLR but they are all over £100 and my budget is under £100 yes I know! Film SLRs are a hassle regarding carying films around but it seems they might be the only other option. Where could I find a second hand digital SLR under £100 or a pentax film camera?

Stephen, I would not recommend getting a film camera. While you might save some money now, you're going to pay for it later with development and film costs.

I would also recommend against purchasing a new SLR camera with only a £100 (US$160) budget. Anything you purchase will be of such bad build quality (because they've had to cut costs to keep the price down) that you'll waste your money.

You can get a pretty good Point and Shoot camera for £100 these days, even with a zoom lens. Like the Canon PowerShot SD1300. Amazon sells secondhand cameras if they'll ship to your location, or you can pick up a cheaper model that's a few generations old on ebay.

Good luck with your search.

Ray Mitchell wants to know why deleting photos puts his shots out of sequence.

Hi David, your tips are invaluable and I eagerly look forward to them..Thanks.

I was told that when photos are deleted in the camera (rather than in a computer) the sequence of taking the photos is lost. e.g. I was told to make it a point to  "never delete in the camera".

On a trip of about five days, and taking about 500+ photos, I deleted many of them them in my hotel room each evening to make sure I had enough space on the card for the next days photos. At the end of my trip, after transferring my photos to a computer, I was quite astounded to see that the sequence in which I know I took the photos was at odds with the sequence in which they were shown on the computer. In other words, photos taken in Calgary can wind up in a sequence of photos taken the previous day in Vancouver.  Your views?

Yes, that's what some cameras do. It's all about file names. When you delete an image, the filename is able to be re-used. So that's how you get out-of-sequence photos.

For example, my Canon numbers it's shots this way: IMG_0001.JPG, IMG_0002.JPG, IMG_0003.JPG, IMG_0004.JPG. If I then delete photo 2, IMG_0002.JPG, when I take my next photo, my Canon will use that filename again, as it's now free.

Fortunately, there's a very easy fix. In your computer, order your images in DATE order, not filename order. That ensures all your photos are in the correct order and Calgary won't get mixed up with Vancouver.

Tim Smith from Canada (who can probably tell Calgary from Vancouver!) asks:

I took a picture on my phone camera and put it to my pc. But the photo has some of the top missing. When I put it into paintshop pro x3 I can see the whole picture, so how do I save the print and put it in for my desk top saver

Hi Tim. I'm guessing from your email that it's only cropped when you place it on your desktop as a background? If so, then you've come across a similar problem as happens when we all try to print photos from point and shoot cameras. Because your camera has a different aspect ratio to your desktop, it's not going to be able to fit the whole image in. So it chops off the top and bottom.

I wrote an article a little while ago explaining why printing crops your photos. In your case, I'd crop your photo in your image program first. That way, YOU are in control of what gets chopped off rather than your computer. Another option could be to check your computer's desktop settings. There's probably an option that will tell it to show the whole image and not crop it.

Nato van Tonder from Hartbeespoort, South Africa has a lens question:

I’m in the process of buying a Nikon D5100 SLR camera but the one thing in concerned about is buying the right lenses. So far I’m considering: All Nikon lenses 18-105mm f/3.5-5.6 + 50mm f/1.8 and 55-300mm f/4-5.6

You don't mention what you want to mostly take photos of, as that affects your lens choice. However, those three lenses are a great combination for general use. The 18-105mm handles landscape and portraits; the 55-300mm is great for telephoto (zooming in) and the 50mm is a fantastic lens just for portraits.

I'd go with those. If you're short on cash, the one I'd drop is the 50mm f/1.8. That's a great portrait lens, but can be covered with the other two.

Oh, and if you're not sure what the mm numbers mean on your lens, see my article What Does The MM Mean On A Lens?

The last question today is from Tina McCoy from Birmingham, UK:

What is the minimum size memory card would u use to photograph 350 prom photos with a lumix G2 camera

It depends on how you're going to save the images. Your G2 camera has a 12.1 megapixel sensor, so if you are going to save in RAW, the images will be around 18 megabytes each. That means you'll need a 6.3G (gigabyte) memory card to store all 350 images. I got to that figure by multiplying 18M by the 350 photos = 6,300M = 6.3G.

If, however, you save in JPG format, each image will only need around 2.5 megabytes to store, so you can fit all photos easily on a 1G memory card. You can increase the compression of your JPG images, or lower the image size to get more photos onto your camera, but if those 350 photos are for a wedding or other such memorable event, I wouldn't scrimp on memory size. Choose the lowest resolution and purchase a large memory card.

If you're after the file size estimates for the megapixels of a different camera, checkout the Megapixel Calculator.

I hope that helps!

If YOU have a question, please feel free to send in your question on my Ask David page. Because of the amount of questions I receive, I can't always answer your specific question, but I do try!

Most people think this post is Interesting. What do you think?


  1. ruben says:

    Is it safe to buy a camera like EOS60D DSLR camera (Body Only) from the Grey Market? Why are they cheaper? I'm confused.

  2. David Peterson says:


    There's no limit. Some people have left the shutter open for YEARS!
    There's no effect on the lens or sensor, but the longer you leave the
    shutter open, the more noise you will introduce into the image.


  3. Lan says:

    i want to know is there a limit of how long you can open the shutter in bulb mode ( in terms of effect on camera ) and is there any effect on lens or sensor etc if using bulb mode frequently. tq

Leave a Comment

Your email address will not be published. Required fields are marked *