Advantages and disadvantages of digiscoping. (1 Viewer)

[petemorris]

I agree with trco's initial assessment. Furthering your £20 note example, if using a 12mp camera, you can have 12mp of the whole note, or, with cropping factor, 12mp of the rolled down note. To put it another way, if you wish to obtain a full frame 12mp image of that note, you'll need a longer focal length lens to achieve that, from the same point, with a full frame sensor compared to a smaller sensor. That's why compact cameras achieve high magnification with small lenses. I can zoom in impressively with the 24mm lens on my coolpix (equivalent of c135mm on a 35mm sensor camera), but would struggle to get close up with a 24mm lens on my 40d!

So, yes, the focal length remains the same on the two cameras and yes, having a smaller sensor does effectively have the same effect as using a longer lens.

Indeed, taken from the luminous landscape article mentioned: Canon D60 with EF300/2.8L IS lens with 2x Extender (960mm Equivalent Focal Length).

 

[Musoman]

Indeed, as long as people point out that this equivalent FL doesnt increase the magnification, but is merely the equivalent of the decreased FOV that a longer lens would achieve.

Many commercial sellers dont explain that bit, as they'd like the uninformed buyer to take the notion that the buyer gets some magical increase in focal length on a crop cam. They dont, and thats a fact.

A 300mm lens on 1.6 crop cam has the same FOV as you would get when fitting a 480mm ( 300x1.6) to a FF camera. Thats all any buyer will get - a cropped FOV thats the equivalent of a longer lens on FF body, in a nutshell

 

[wavering]

Tommy,
If you need a scope to watch birds out in the fields/wetlands then it could make sense to add a camera as well to take photos. It doesn't make sense these days to buy a scope just to take photos. In the olden days a digiscoper was out-shooting the DSLR guys by a large margin but now there is not much in it. The DSLR guys have longer lenses( eg Canon 800/5.6 ) and many more megs in the camera.
If you want to improve your current setup get the Canon 400/5.6 lens.
Neil

I too have a Canon Body and a Sigma 50-500 which is OK but I am getting restless! Do you think the "Canon 400/5.6 lens" is that much better? I guess I would probably use it with a doubler too ..
Bob

 

[Neil]

I too have a Canon Body and a Sigma 50-500 which is OK but I am getting restless! Do you think the "Canon 400/5.6 lens" is that much better? I guess I would probably use it with a doubler too ..
Bob

Yes.

 

[kristoffer]

Advantage for a birder: You wont have to drag along a lens and dslr-body + more stuff with your other equipment. The scope you bring will double as a viewing and photograph instrument. You only need the compact and an adapter. And you wont get ruined from buying mega expensive lenses.

But if you are a photographer starting from scratch, buy the dslr and lens.

 

[Roger P]

Ohhh, I understand now - thanks for that and for link. Looks like I was wrong whole time Well, no more

I'm still not sure you were wrong.

Quote from the website referred to:

"This is great for nature and sports photographers as the net result is more real pull than before with no trade off of maximum F Stop loss."

All the £10 note analogies miss the point that if you were to print an image onto (for example) 6 x 4 paper you wouldn't leave a white border round the image to compensate for the crop, you'd fill the paper. The net effect is that your bird looks bigger on the print and that's what we are after surely?

I understand (actually I'm not convinced that I do!!!) that there may be depth of field issues etc but generally in bird photography we are looking for ever larger, clearer images. What this thread does not consider is the number of pixels and their 'quality'

 

[trco]

I'm still not sure you were wrong.

I'm getting confused :-C :-C:-C

 

[Musoman]

People are confusing you trco, so there's some more help here. Again, explained much more professionally than i can explain

http://www.robertsimaging.com/help/topic-crop-factor.jsp

Just be aware, that a 500m lens on a 1.5x crop camera does NOT increase the focal length to 750mm. The Angle of View or Field of View changes, and you will see the equivalent FOV of of what a 750mm lens on a FF camera will see.

And here's another saying exactly the same thing.

http://www.digitalcamerareview.com/default.asp?newsID=3611

 

[bughunter]

Just be aware, that a 500m lens on a 1.5x crop camera does NOT increase the focal length to 750mm. The Angle of View or Field of View changes, and you will see the equivalent FOV of of what a 750mm lens on a FF camera will see.

Yes, but who cares about FOV?
The user with a 500mm lens with a 1.5 crop factor get the bird full framed on his sensor as the other guy with a 750mm lens and a FF cam.
So, both have a bird in the same distance full framed on the cam, THAT fact matters. So to the users it looks like using a 750mm also on the cam with crop factor.
Of course there are differences later because of different numbers of pixels and if you compare the pics on pixel level, but that is not a point of discussion for a given cam.

So for "daily discussions" it is ok to say as a first approximation, that a crop factor is increasing the focal length, if your target is to get a bird full framed.

 

[Musoman]

Nope.

Bung the 500mm lens on the Full frame camera, and simply crop the extra FOV off of the resulting photo, and you get what that 500mm lens on the crop camera would have seen.

Simple as that.

 

[Steven Astley]

Nope.

Bung the 500mm lens on the Full frame camera, and simply crop the extra FOV off of the resulting photo, and you get what that 500mm lens on the crop camera would have seen.

Simple as that.

Only you will be using less pixels, if both cameras have the same number of megapixels.
The way I see it, there's actually focal length, which with my superzoom, is about 85mm. Then theres is the useful one in comparing magnifications of cameras with different size sensors, which is known as 35mm equivalent, on my superzoom this is 487mm. Its calculated using crop factor.

Although smaller sensor cameras produce bigger images, bigger sensors are better in poor light and hence usaully produce a better image than a camera with smallere sensor but same number of megapixels.

 

[Musoman]

Agreed Steve. I know what crop factor does, and it affects the FOV. There is no extra reach. There never was, and never will be

All that i'm aiming to do is dispel the perpetuated myth that there is some skull duggery that turns a 500mm lens into a 750mm lens, by simply swapping it from one camera to another.

 

[lmans66]

Advantage for a birder: You wont have to drag along a lens and dslr-body + more stuff with your other equipment. The scope you bring will double as a viewing and photograph instrument. You only need the compact and an adapter. And you wont get ruined from buying mega expensive lenses.

But if you are a photographer starting from scratch, buy the dslr and lens.

What is said is correct but......but.....it is much more difficult getting a shot of a small active bird in clear detail with a scope as opposed to using a camera. (and be proud of the shot) For instance, if I want to shoot water foul, no problem with the scope. If I want to shoot a sparrow in the bushes, a bit more difficult. The sparrow is moving more rapidly, thus making it harder to 'catch and grasp in focus' with the scope and point and shoot camera. Now I am not saying it cannot be done but, beware...it is not as easy and still have an excellent shot. Most of your shots will be ID only shots.

I find that having both worlds is best. A scope for water foul and other larger type birds but have a camera plus a good lens for smaller birds. But than again, more money is needed.

 

[kristoffer]

Yes, but if you already is a birder, you already got the scope and only need a cheap camera and an adapter, then you are ready to go. It´s quite expensive to get a good dsrl and 400mm+ lens. Naturally if money isn´t a problem it´s better to buy the best photo stuff you can get, but for most ppl, money is a problem. Then the scopes reach can´t be beat since you cant afford similar lenses.

What is said is correct but......but.....it is much more difficult getting a shot of a small active bird in clear detail with a scope as opposed to using a camera. (and be proud of the shot) For instance, if I want to shoot water foul, no problem with the scope. If I want to shoot a sparrow in the bushes, a bit more difficult. The sparrow is moving more rapidly, thus making it harder to 'catch and grasp in focus' with the scope and point and shoot camera. Now I am not saying it cannot be done but, beware...it is not as easy and still have an excellent shot. Most of your shots will be ID only shots.

I find that having both worlds is best. A scope for water foul and other larger type birds but have a camera plus a good lens for smaller birds. But than again, more money is needed.

 

[RJM]

Taken today from ~100m. The detail in this small buzzard would be impossible at this distance with even the longest, biggest dslr lens costing US$20k. This is THE ADVANTAGE of digiscoping.

Rick

 

[Paul Corfield]

Yes it's better than a dslr and lens, but at 100m I can do much better with a dslr and astro scope which for me perfectly fills the gap between a dslr with a lens and a spotting scope and it's a fraction of the cost of either set up.

Paul.

 

[Atricapilla]

Yes it's better than a dslr and lens, but at 100m I can do much better with a dslr and astro scope which for me perfectly fills the gap between a dslr with a lens and a spotting scope and it's a fraction of the cost of either set up.

Paul.

Hi Paul ,
Could you tell us which dslr and which astroscope you use please as I am very interested.

 

[polaris2]

Hi Bob

Check out Pauls and others gear at:
http://www.birdforum.net/showthread.php?t=158669

 

[Atricapilla]

Cheers P2

 

[trco]

People are confusing you trco

OK, I believe I understand it this time

If I have crop camera like EOS 50d and FF camera like EOS 5D and if I put 500 mm lens on both of them then I get larger image on 5D. Then I can crop image to 15mpix and get roughly same image hipoteticaly.

But, if I have crop camera like Nikon D300 and FF camera like Nikon D700, both with 12mpix then I can get larger photo of subject with D300. If I use 500mm lense on both of them.

Am I right?