focal length question

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i read somewhere maybe it was in the bird section that you would ideally need a lens of about 300mm to get any good results when photographing birds.

what i want to know is it 300mm on a 35mm equivalent or full-frame DSLR or is that 300mm on a crop sensor where you need to multiply the focal length by whatever amount in effect making it a 35mm equivalent of say 480mm or 600mm or whatever ratio the cropped sensor is?
 
I've only tried to shoot birds a couple of times but I went with a D300 (1.6x crop) and a 70-200mm lens which gives a 35mm equivalent of 320mm and it definately wasn't enough so if you are on a crop sensor then I'd recommend going for a 300mm lens to get the equivalent of about 480mm.
 
A 300mm on a crop body is more than enough but it depends how good you are at getting close :D
 
They probably meant a 300mm on a crop sensor. You can get good bird shots with a shorter focal length but a longer lens will give you more opportunities.

It all depends on the size of the bird, how far away it is and how much you are prepared to crop the picture.

This was taken at 200mm (300mm ~ 35mm equiv.) and cropped to about 70% of the original size.
DSC_3148.jpg
 
Dependant on a number of factors as already stated..

- How sneaky you can be
- What species you are going after
- Available light
- Whether you plan to use a remote trigger

A local spot where I go, I can photograph woodland birds with my 70-200 on a 1.3 crop (so around 280mm 35mm equiv) and not need to crop at all. Whereas if I tried this combo on a golden eagle in Scotland... the results would be somewhat different!

If you are just starting out, and looking to photograph common birds then 300mm, with a little patience and hard work will be enough. Although you will need to invest in something longer when you up your game :)
 
Check out the bird forum and see what people are using. 300mm on a crop body is the minimum focal length really, and even then you will need to get within a couple of meters to get a frame filler of small garden birds.

Rule of thumbs is that you cannot have too much focal length for birding. Since 1000mm lenses are just not on, then birders will use the longest lenses they can get, will move as close as they possibly can, and even then sometimes have to crop the image.
 
I do a bit of birding from time to time

My lens is a 300mm, but I regularly put a 1.4x on giving me 420mm and still sometimes that is not enough for the small birds.
 
thanks for the advice and input, much appreciated :)
 
It is down to distance.... I don't normally shoot birds but will photograph anything that moves :lol:

Anyway my best bird shot is this:

bird100.jpg


This bird (and I don't even know what it is) landed in the car park at Haweswater and proceeded to run around on the wall 20 feet away. I could have got it with the 20mm :) The point is that you can try and get nearer and you can crop the image. The above image is uncropped, at 50mm and cropped it would still have been acceptable.

You could look at a Kenko PRO 300 1.4TC which works with all lenses. Just bought one mainly for use with my 80-200 and there is little loss of IQ (well I can't really see any with the shots I have done)
 
cowasaki said:
You could look at a Kenko PRO 300 1.4TC which works with all lenses. Just bought one mainly for use with my 80-200 and there is little loss of IQ (well I can't really see any with the shots I have done)
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Darren, are you deffo going to the Martin Mere meet? If so then any chance I could have a go with this TC on my Nikon 70-200mm. I've been thinking of getting a TC but as I'd only give it occasional use I want to make sure I get something that works well when I do use it.

Even if you're not going to the MMM you're only 10 mins down the road ;) :thumbs:
 
-Rob- said:
Darren, are you deffo going to the Martin Mere meet? If so then any chance I could have a go with this TC on my Nikon 70-200mm. I've been thinking of getting a TC but as I'd only give it occasional use I want to make sure I get something that works well when I do use it.

Even if you're not going to the MMM you're only 10 mins down the road ;) :thumbs:
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Yes I am definitely going. You can certainly have a play with the TC. Darren "Wack61" sold me the Nikon 80-200 and told me to get the Kenko TC. He then kept spotting them on Ebay for me but I kept missing them then just got in on time with this one. Someone else was asking all manner of questions so I just jumped in and grabbed it :) They regularly go 2nd hand for about £50-65, I got mine for £54+5. It is like new just minus the box and works on all my lenses (It's like having a cropped body adapter)!
 
As everybody says it depends on how tame your birds are. But just bear in mind that the longer the lens then the higher the f stop (smaller apature) needs to be to get enough depth of field for all of the bird to be in focus. So sneaky is best and cheapest.
 
Beagletorque said:
As everybody says it depends on how tame your birds are. But just bear in mind that the longer the lens then the higher the f stop (smaller apature) needs to be to get enough depth of field for all of the bird to be in focus. So sneaky is best and cheapest.
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That's not actually true. If you frame the bird the same size in the viewfinder, DoF will be same regardless of focal length.

However, field of view changes quite a lot, often giving the impression of greater isolation with a longer lens, but it's not a depth of field effect.
 
HoppyUK said:
That's not actually true. If you frame the bird the same size in the viewfinder, DoF will be same regardless of focal length.

However, field of view changes quite a lot, often giving the impression of greater isolation with a longer lens, but it's not a depth of field effect.
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True. The point I was hoping to make was being close with long lenses isn't always the best way to go. Being close with shorter lenses can be better, never mind my signature.
 
As a general rule you can never have too long a lens for birds, I shoot with a Sigma 150-500 and I use a 1.4 on that at times and crop. Good fieldcraft getting close and using a hide or camoflage can get you shots with a shorter lens. You can also try setting your camera up focused on a known perch and fire remotely. Birds will go for food so some bait is a useful trick.
 
Can I just put something right here. Putting a lens on a small sensor camera DOES NOT give an increase in either magnification or focal length. An object photographed at a given distance with a given focal length will have a given image size no matter what camera you put it on.

As an example, the following image was originally taken with an 80mm lens on a 6x6 medium format camera. If I had used an 80mm lens on a 35mm camera from the same distance, I would have got the image within the red rectangle and with a small sensor, approximately that within the yellow rectangle. NO increase in image size, merely an increase in the cropping around the subject.

mountain_hare.jpg


:bonk:
 
Somelier said:
Can I just put something right here. Putting a lens on a small sensor camera DOES NOT give an increase in either magnification or focal length.
Click to expand...

Most of us completely understand this and have explained it to others over and over! and over and over :)

But it you are taking a picture of a bird on a branch 100 feet away with a ff sensor camera and then take a picture of the same bird with a cropped sensor camera then you get no more magnification but what you do get is more pixels in the area of the bird itself.

So in your example if I took an image as per your diagram using my D700 I would have 12Mpx across the red section. If I then cropped it to the yellow section where my target birdie is I would be down to 7-8Mpx. If I had taken the picture with the D200 I would have 10Mpx in the yellow area.......

This is the main advantage of a cropped sensor
 
glad i asked the question now :) after reading the last couple of posts i think i understand it a bit better now.

300mm focal length is 300mm focal length regardless of whether it is on a crop sensor or full frame/35mm film camera. you just see more of a picture on a full frame/35mm film :)

thanks for the extra input :thumbs:
 
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