Perhaps I will be showing my extreme ignorance here, but here goes anyway! I shoot with a D7000 and have been very happy with the results from my 70-300 FX, especially at 300. Thought I might like a bit broader range though, so I just got an 18-300 DX. I did this accidentally- I thought I was ordering the 28-300 FX.
Decided to do a side by side comparison of the two lenses, so I went to my deck and set up, as I commonly do, to do some closeup shots of the Hummingbirds that frequent my feeders. Shot with the 18-300 at first, zoomed to 300. Thought something didn't look quite right- the birds did not seem to be as "close" as usual. After a few minutes, I went into the house and changed to my 70-300. Went back to the same spot, left the manual settings the same, zoomed to 300, and looked through the viewfinder. Now the hummingbirds were filling up the entire viewfinder, and on review, the images from my 18-300 were definitely not as close a zoom. Looked more like shots taken with my 70-300 at 200 mm.
Is this because it is a DX lens? If so, would the 28-300 be the same as my 70-300 at the 300 end? And is it a good lens for the D7000? I've seen some mixed thoughts on that. Regardless, the 18-300 is going back.
Sun 09-Sep-12 02:11 PM | edited Sun 09-Sep-12 02:39 PM by MotoMannequin
This has nothing to do with the DX designation.
You may have noticed that your lenses will appear to zoom very slightly as you adjust focus, even if you haven't touched the zoom setting. This is called "focus breathing" and some lenses do it a lot more than others.
You should find that your 70-300 & 18-300 give a very similar view at 300mm when focused at infinity. As you focus closer, the 18-300 will "breathe" more than the 70-300.
To your question of whether the 28-300 will be better than the 18-300? I don't specifically know the answer to this question, but my instincts tell me that the focus breathing is a necessary consequence of designing a super-zoom so I wouldn't expect either to do as well as your 70-300.
Edit: To take this a bit further, if you don't mind getting technical...
I looked up the max reproduction ratios of these lenses: 70-300 = 1:4 28-300 = 1:3.1 18-300 = 1:3.2
Which means, as close as you can focus, the 70-300 can fill the frame with something 4x the width of the frame, or on DX 4x24mm = subject 96mm or 4" wide. The 28-300 and 18-300 should will both be able to magnify the subject about the same, in this case they can fill the frame with something about 3x24mm = 72mm or 3" wide. Both these lenses offer slightly more magnification than the 70-300!
How is this possible? Let's look at the minimum focus distance: 70-300 = 150cm 28-300 = 50cm 18-300 = 45cm
Here you have it. You can move the lens much closer to your subject with either of the superzooms, and this gets you more magnification.
To look at this another way, you get get about 33% greater magnification with the 28-300 or 18-300. You might think that at the same focal length, you'd achieve this by moving 33% closer, but because of focus breathing you need to get 300% closer to get this additional magnification!
If your subject is skittish (like hummingbirds) then having a closer min focus distance might not be an advantage.
Anyway, by these numbers, the 28-300 offers very slightly more magnification than the 18-300, and does so at a very slightly longer distance, which tells me that the 28-300 doesn't "focus breathe" quite as much as the 18-300. But these are both "heavy breathers" and for practical purposes I'd consider their performance in this respect to be identical. You'll probably be disappointed if you exchange lenses in an effort to correct this issue.
Again, this has nothing to do with DX vs. FX. The DX designation just means the lens has been built to a smaller diameter to cover the smaller DX frame.
Thank you Larry! I think I'll stick to the "if it ain't broke, don't fix it" motto, and just be happy with me 70-300, and just switch lenses when I need to go wider! So back goes the 18-300 and I'll skip the 28-300 as well.
Your post interested me. I also have a 70-300 which wasn't quite doing it for me when shooting track events, since I need a little more wide angle in some shots. Not much fun trying to change lenses or even cameras in a split second when following a group from the start to the finish in a 100M Sprint, for example.
I recently purchased an 18-300mm and have just started trying to learn its pros & cons, and how best to use it. Most complaints I've heard is about soft focus at 300mm wide open.
Here is a shot off my deck at a hummingbird on my Rose of Sharon "tree". First at full shot, & then super cropped. I guess I need to do the same thing with my 70-300 & my 18-200mm. If anyone knows the ID of this hummer, I'd be interested. There are not supposed to be anything in this area except Ruby Throats.
BTW, This was shot handheld. 1/125 -- f9 -- Center WeightedAverage (Forgot to change that) -- 240mm (Tried not to shoot full focal length) -- Auto Exposure (YIKES! I grabbed the camera really fast when I saw the hummer & forgot to reset from when I had someone else shooting me at an indoor event with flash) Another test will be soon.
That is either a female or a juvenile Ruby Throated Hummingbird. Only males get the distinctive red throat, and only after their first winter. This time of year you may see one or two red feathers starting on their necks.
Here's a shot of a male I took on my deck earlier this year, with my 70-300. It's a tight crop. Shot at 300 mm using f6.3 1/800 and ISO 720.
Hmmm... Got to get my 70-300 out & try that as soon as a see the hummers out. Yours looks a lot sharper. Was it handheld or on a tripod? I don't have a feeder anymore & have to catch them in the wild (many different locations.
My late wife was known as the Hummingbird Lady. One of the local TV stations came out to do a story on a nest that was clearly visible on a low branch. They also did a spot on my in-laws two feeders that would gather 20+ hummers at a time. (It's my understanding that this is very unusual.) They varied slow motion with real-time using Rimsky-Korsakov's Flight of the Bumblebee in the background.
These are nice. I would ask hummer #2 not to drool so much when being photographed.
Trying out my 70-300mm today, I ran into some issues that I hadn't noticed before. Guess I'll head on over to the lens section to see if I can get an answer. It may be one of those heavy breather issues.
In answer to your question, the 70-300mm becomes effectively a 105-400mm lens when used on a APS-c body such as your D7000. It is the result of a DX sensor being smaller than a FX sensor. Resulting in a 1.5 magnification factor for an FX lens use on a DX body. The DX lens being designed to cover the smaller sensor where the FX lens is designed to cover the larger sensor. The side benefit to using the FX klens on the DX body, in addition the magnification, is that you shooting closer to the center of the lens, thus losing distortions from the edges of the lens. Liked everyone's pictures, Happy shooting.
I'm sorry to have to correct your first post here, but the DX "crop factor" applies equally to both lenses being discussed here - indeed to all lenses.
On a DX camera, the 70-300mm will give you the same angle of view that you would get from a 105-450mm (not 400mm) lens on a full-frame FX camera. Similarly, the 18-300mm on a DX camera will give you the same angle of view that you would get from a 27-450mm lens on an FX camera.