24-70mm f/1.8 DX

Sports

If Sigma can build a big 18-35mm f/1.8 DX lens, then why not a 24-70 f/1.8?
Wouldn't this be a perfect "close" indoor lens ... and more useful than the 18-35mm?
An FX lens would be huge, but how big would a DX lens be? Anyone??
And Nikon would obviously not build a DX lens THAT attractive, but Sigma, are you listening? :-)

heartyfisher

All the new 24-70 F2.8 full frames seem to be 82mm.. If some one makes 24-70 F2.8 dx it will be at least 82mm filter size. I dont think that will be done. However, if the range is reduced, say 24-50 or 35-70, maybe that can happen. a 35-70 F2 could be nice... i have the old nikon 35-70 f2.8 and used that on my dx cameras it is a very nice portrait lense on DX. I can imagine an F2 version being used as a dx portrait lense of choice.

Why not just use the tamron 24-70 F2.8.. I have, its nice... and it has VC/VR too.

If they do make another DX F1.8 zoom I would like a 55-105 F2. I think that would complement the 18-35 well.

esquilo

An FX lens would be huge, but how big would a DX lens be?

It would be larger than a 70-200/2.8 with a 1.5x speedbooster. That combo would give somewhat longer focal lenght, but only f/2.

heartyfisher

My theory on how big a zoom lens could be goes like this..
using the 24-70 F2.8 as an example
A ) take the long end and devide that by the aperture ( 70 / 2.8 = 25mm)
B ) take the short end and divide that by 58mm {the focal length that does not need retrofocus} ( 58 / 24 ~= 2.5 )

multiply A with B ( 25 * 2.5 = 62 mm )

So my theoretical minimum diameter of the front element is 62mm.
To that you need to factor in Design requirements which currently pushes it out to 77mm and the new ones at 82mm. ( Note that image circle only has a minor effect, part of design )

Note : this rule of my thumb only works for lenses that crosses from normal to retrofocus.

The question is how much of a reduction of the front element size will there be if the image circle is reduced from FX to DX. I would think it will be minimal. From known examples like the 17-55 F2.8 my theoretical rule comes to 67mm(HeartyFactor) the real nikkor is 77mm. so you add 10mm for dx and 15-20mm for fx

So using that to extrapolate the DX 24-70 F1.8 will have HeartyFactor:94 + 10mm = 104mm front element size!!


just for fun the heartyFactor for
1) 24-50 F1.8 = 67 ( 77 dx 87 fx )
2) 35-70 F1.8 = 64 ( 74 dx 84 fx )

F2.0 instead of F1.8 should reduce that by about 7mm. So a 35-70 F2.0 could be as small as 67mm but more likely 72mm. I am sure "marketing" could make a 36.5-67mm F1.87 with 67mm filter and call it a 35-70 F1.8 ;-)

spraynpray

Fascinating hearty. I-)

Sports

Interesting, thanks ......
Yes, it's really "amazing" how big those 24-70 zooms are, especially the new one.
I mean ... when you compare to the almost tiny looking 85mm/f1.8D and the moderately sized 24 mm/f1.8's that exist. It's crossing the retrofocus "boundary" that really adds size, I guess.

tcole1983

I don't think many shoot that range on DX though. It isn't wide enough although nicer on the long end. I can't say I have lusted after the 24-70 that is already available in f2.8. Hard to say what would be really nice. Seems like I frequently have both end pegged on my 17-55...I would maybe give a couple on the wide end for a 20-60 range.

spraynpray

...and I would like a couple more on the wide end like 15-55. ">

Ironheart

Just get the 16-80 f/2.8-4 DX. Problem solved.

tcole1983

Just get the 16-80 f/2.8-4 DX. Problem solved.

Still not sure how I feel about it and it is variable. Kind of a replacement, but not replacement for the 17-55. From some of the samples it didn't look too strong at 80, but could be a number of factors.

@spray...I am not sure I could choose if I had to. I do wish I had a bit wider at times, but I also find when trying to shoot some portraits that 55 doesn't do me well either. I have longer lenses so it being a one in all zoom isn't what I need. If I have the chance I use my 105, but that of course requires switching lenses and or carrying two lenses. If I set out knowing I am taking portraits I put the 105 on, but otherwise the 17-55 is usually on my camera. It is ok at 55, but I think a little bit longer is where you get a decent focal length for my liking to use for portraits.

Sports

I've been tempted by the 17-55/f2.8 as well as the 16-80/f2.8-4, and both would put me in a slightly better position than now. But not enough to make me cough up.
My special mission right now is to take everyday life pictures (early morning to late night, can't help it) of our new baby girl, so it's indoor, bad light, moving, unpredictable target. And we don't want to use flash too much - that changes her focus, stops the cute movements, upsets her, or wakes her up.

The 50/f1.4 gives me the best results, but I very often need a bit wider or a bit longer. That's how the idea of a "baby zoom" came to me. I could easily settle for a 30-70 or even a 35-70 range, but it has to be very fast. That's the point.

Anyway ..... the best tool for this job is a new FX body, I know. With a new lens. So it's too much right now, unfortunately.

And ..... we get more than enough baby pictures already, so it's not really a big problem :-)

Msmoto

OK, I will take a 24-70mm f/2......if this is the thread we simply put our Christmas list on.... )

Oh, yes, full frame....

tcole1983

@sports...yeah bump the ISO up is about the only answer, but on a d300 you are going to struggle. You might be surprised what you can get out of a d5200 even compared to the d300. You can usually up the ISO and keep usable pictures with decent shutter speeds. Although sometimes you just have to use a flash.Faster glass helps, but unless you can shoot it wide open which doesn't really work at f1.4 or 1.8 and keep everything in focus you want.

Sports

... on a d300 you are going to struggle.

True, the ole 300 sure doesn't shine very brightly on its new assignment.
I've been alright so far, as I've been more interested in outdoor, daytime photography, but it's no secret that a new body is high on my wishlist.

Ironheart

I'll echo that a modern DX body with the 16-80 will blow you away. You can easily crank the ISO well past where you are maxing out with your D300. You won't need the heavy expensive glass just to get the light you need, a few clicks on the ISO-o-meter and you are good. Or better yet, use M mode with Auto-ISO. It's my new fav. Get a D7200 you won't look back.

heartyfisher

I reckon that the D7200 + the Tamron 35mm F1.8 VC would be your ideal setup for your "mission". I have the 24-70 VC and with the D7200... night street photography is almost easy..