Contemplating a new (used) lens. Advice please.
Oct 24, 2019 10:01:10 #
Oct 24, 2019 11:19:13 #
Canisdirus wrote:
You are forgetting that you are already at f6.1 as soon as you attach the lens.
How do you figure that? The lens does not set it's aperture relative to an FX or DX camera. f4 is f4 and the tele cuts one fstop of light from entering the camera. f5.6.
FOV is 1.5 because of crop sensor = more reach. The lens does not care which camera it is attached to.
Take the teleconverter out of the equation. I have a 300mm f4 PF prime lens. Everything I shoot at f4 is f4 and EXIF data in LR says f4. Without a teleconverter, it is f4, on my D500 and on my Z7. Add the extender... lose one stop of light. f5.6.
Oct 24, 2019 12:00:19 #
Canisdirus wrote:
You are forgetting that you are already at f6.1 as soon as you attach the lens.
You are forgetting that the fstop is a characteristic of the actual focal length of the lens and has nothing with the equivalent focal length.
Oct 24, 2019 13:55:58 #
mikeroetex wrote:
How do you figure that? The lens does not set it'... (show quote)
I am not saying the aperture changes ... as I have already mentioned.
The DOF is different....as is compression.
An f/4 lens DOF on a FF ..... is the same DOF as his Nikon D7000 at f/6.1.
You gain focal length (field of view), but nothing is free.
DOF and compression changes.
Once again, and for the very last time (at least for me) .... the amount of light is exactly the same passing through the lens. It doesn't care what it is attached to. But the smaller sensor of an aspc does make a difference positively for field of view, and negatively for DOF and compression.
I can't explain it any simpler.
PS. The '1.4' multiplier used by Nikon, is an approximation number.
But that would look lousy for marketing ... so the round the number for sales purposes.
Why my FOV multiplier is not exactly 1.4.
Oct 24, 2019 14:39:14 #
Canisdirus wrote:
I am not saying the aperture changes ... as I have... (show quote)
If you are talking about DOF then say so - right from the beginning ! The (natural) assumption with crop factor is for FOV and for extenders LIGHT loss relating to exposure - and deservedly so !
.
Oct 25, 2019 08:55:14 #
imagemeister wrote:
If you are talking about DOF then say so - right from the beginning ! The (natural) assumption with crop factor is for FOV and for extenders LIGHT loss relating to exposure - and deservedly so !
.
.
I did say so ... several times.
As well as FOV.
In the end ... if you are u8sing an aspc camera, and you want to shoot wildlife ... you want the fastest lens possible.
Why I shoot with a 300mm f/2.8 & not f/4.
Oct 25, 2019 09:14:43 #
Canisdirus wrote:
I did say so ... several times.
As well as FOV.
In the end ... if you are u8sing an aspc camera, and you want to shoot wildlife ... you want the fastest lens possible.
Why I shoot with a 300mm f/2.8 & not f/4.
As well as FOV.
In the end ... if you are u8sing an aspc camera, and you want to shoot wildlife ... you want the fastest lens possible.
Why I shoot with a 300mm f/2.8 & not f/4.
Yet you are disregarding their budget concerns....
Oct 25, 2019 09:31:05 #
Screamin Scott wrote:
Yet you are disregarding their budget concerns....
I only corrected the lens math conversion.
If you don't know where you are ... you will have a more difficult time of it.
Now he knows.
If budget is a concern ... do nothing. Any long lens at f/2.8 will be expensive.
One must also consider that in the new digital photography age, lenses and camera bodies don't all pair as well as other combinations/brands. Unlike the old analog days, where the heart of all cameras was basically the same. Film/shutter/aperture.
Meaning that a lens that will be stellar on one camera body, will not be as good on another.
Pairing body and lens is more complicated now.
Oct 25, 2019 11:05:18 #
Canisdirus wrote:
I did say so ... several times.
As well as FOV.
In the end ... if you are u8sing an aspc camera, and you want to shoot wildlife ... you want the fastest lens possible.
Why I shoot with a 300mm f/2.8 & not f/4.
As well as FOV.
In the end ... if you are u8sing an aspc camera, and you want to shoot wildlife ... you want the fastest lens possible.
Why I shoot with a 300mm f/2.8 & not f/4.
Aye, there’s the rub. You say your taking about DOF, but when it comes down to it most people talk about wanting a low aperture for speed. Especially for the kinds of subjects they’re usually shooting. At those longer distances a little more DOF can be a good thing, especially with a moving subject.
Oct 25, 2019 11:27:49 #
Canisdirus wrote:
I am not saying the aperture changes ... as I have... (show quote)
All lens specs are approximations. Always have been. Some are closer than others to the listed spec. It's all about marketing and sales...
Oct 25, 2019 15:38:07 #
Retired CPO wrote:
Another absolute bargain lens for the performance you get is the Nikon 200~500 at about $1,300. Very sharp from end to end and 750mm equivalent on a D7000. It's f 5.6 so a little slow for the deep woods but the D7000 does pretty well with higher ISO. ps. It's GREAT on the D500.
Oct 25, 2019 15:42:05 #
Sinewsworn wrote:
While a good lens, it's nowhere near their $300-$500 budget thus not a candidate.
Oct 26, 2019 09:25:50 #
SuperflyTNT wrote:
Aye, there’s the rub. You say your taking about DOF, but when it comes down to it most people talk about wanting a low aperture for speed. Especially for the kinds of subjects they’re usually shooting. At those longer distances a little more DOF can be a good thing, especially with a moving subject.
It's both. Wildlife shooting ... fastest aperture lens and best subject isolation ... which still brings you back to the largest aperture DOF.
It doesn't mean you will be shooting at the largest aperture all the time ... but it gives you more options.
If you want to reply, then register here. Registration is free and your account is created instantly, so you can post right away.