PhotoWalkPro

I received a question the other day from a reader asking me about lens compatibility for his Canon 50D. Basically his question was if a EF 70-200mm f/2.8 L lens would be compatible with his camera. The good news is yes, it is compatible. The bad news is that if he purchased any EF-S series lenses, they would not be compatible if he ever moved up to a full frame camera. That’s because the EF-S lenses are made specifically for the smaller APS-C sized sensors in cameras such as the 50D, 7D, and all of the digital Rebel models.

EF-S lenses are made to have a shorter back-focus, meaning they sit back further in the camera than a standard EF lens. This helps the lens provide better coverage for the smaller sensors, especially for wide angle lenses. So while the short back focusing EF-S lenses are great on APS-C cameras, they can’t be used at all on full frame cameras such as the 5D Mark II. Knowing this, you might want to give consideration to which lenses you plan on buying in the future. If you don’t think you will ever move up to a full frame camera then you can pretty much buy whatever lens you desire without fear of it becoming obsolete. If, however, you think that a full frame is in your future you might want to consider only investing in EF lenses.

And you Nikon shooters have the same problem only not quite as severe as Canon. If you are shooting with one of the non-full frame cameras such as the D3000, D5000, D90, or D300s, you have the option of buying standard lenses or the DX style lenses. The DX lenses are the equivalent to the Canon EF-S lens and are also short back focusing lenses. The good news for Nikon shooters is that the DX lenses will still work on full frame bodies…sort of. So here’s the deal, if you put a DX lens on a D700, D3s, or D3X the camera will automatically enter into what Nikon calls DX mode. This means that, due to the reduced lens coverage, the sensor is cropped down to a smaller size to accommodate the DX lens. So the lens will work on the camera but with a reduced image resolution.

Any way you slice it, it pays to do some forward thinking when purchasing lenses, especially if you own a camera with an APS-C or DX sensor. Because camera bodies can come and go but a good lens can last you decades.

I have been focusing my camera a little differently lately thanks to a little used feature on my Nikon DSLR, the AF-On button.  This button that hangs around the back of the camera doesn’t get much love from most photographers but I think if you give it a try you might find that it becomes your primary focus method.

What it does -

When the AF-On feature is activated in the camera, the focusing function is taken away from the shutter relaease button and assigned to this button on the back of the camera. When the button is pressed, the camera’s auto-focus system will activate and focus using whatever AF mode you have selected. It also means that pressing the shutter release button will now only activate the shutter, not the auto-focus.

Why you should use it -

You might have come across a circumstance where you are shooting a subject where there are obstructions that move between you and the subject but you still want to continue shooting with your subject still in focus. If your camera is using the shutter release button to focus you might have trouble maintaining focus because the obstructions are now in front of your focus point. If you use the AF-On feature, you can focus and then release the button and then take your picture with the shutter release button. You can keep taking photos using the shutter release and the camera will not try to re-focus until you press the AF-On button once again. This is also handy if you like find yourself focusing and then recomposing a lot. Usually this means that you have to hold the shutter release down halfway. With the AF-On button, simply place your focus point where you want it, focus the camera, then let go. No you can recompose and not have to press the shutter release button until you are ready to shoot.

It might seem a little weird to use this feature at first but I bet that once you start using it, you won’t want to go back to the old way of shooting.

Hey everyone, I just received word that my latest book, Nikon D3000 – From Snapshots to Great Shots is available for pre-order.  I expect to have the writing all wrapped up by the end of this month if all goes according to plan (maybe sooner if I get a few more snow days).  I don’t have an official shipping date but I would expect to see it on store shelves by around the beginning of April.  I’m also checking out the possibility of another book after that but I don’t want to announce anything just yet because you all know how things go in the camera market. Just when you decide on one thing, BANG, here comes another camera out of the gate. Read the rest of this entry »

Being out of town for a few days I didn’t really get a chance to do much in the way of news updates so I thought I would bring you a few little nuggets that I heard about lately.  And as you probably know, PMA is just around the corner so some of the camera manufacturers have started releasing new product info to help feed the buzz. Read the rest of this entry »

Have you ever looked at one of your images that was taken with a wide-open aperture setting and noticed that the focus is off?  Maybe it appears to be behind where you thought you focused?  This may be due to the lens system doing something called back-focusing.  Usually it’s not extreme and only really noticeable when shooting wide-open but if you are doing any sort of macro work, it can be very frustrating.  You can also have the opposite problem where the area of sharp focus is in front of the intended focus point, called front-focus.  The easiest way to check this is to print a focus chart, put your camera on a tripod at a 45° angle, focus on the center point using the auto-focus, with the lens set wide open, take a photo, and then look at your image on your computer at 100%. Read the rest of this entry »