[Pål Jensen]

APS-C lenses need to be a stop faster than their full frame equivalent lenses to be fully equivalent.
This is equivalency 101, and has been batted around as a talking point by the equivalency crowd for a decade.[COLOR="Silver"].

Lenses with the same angle of view for different formats can never be fully equivalent. The equivalence crowd is ignoring this fact and state that only DOF wide open matters, something that is a completely subjective opinion. We had no equivalence discussion in the film days as everyone understood that using a Pentax 6X7 over an LX wasn't because you could use 64000ISO in the former to get the same output as the latter at 100ISO. 1.4 is never equivalent to F.2. Just ask any lens manufacturer.
The equivalence misunderstanding is based on the false assumption that you want the same output from two different formats and wrongly insisting that the lens aperture is defined by the lens DOF

---------- Post added 07-08-21 at 12:35 PM ----------

Most people buying into those sensor sizes will know that they're losing out on equivalence in terms of depth of field when compared to FF so it makes no sense to say you need an f/1.4 APS-C lens to get equivalent to a FF f/2 lens..

Or gaining. All you do when comparing lenses with same angle of view from two different formats is transposing the DOF scale towards deeper DOF on the smaller format. What DOF range is most desireable is 100% subjective and depends on subject and what effect you want to create. The assumption that paper thin DOF is always desirable is false in most cases as most successful images require some DOF. and is anyway purely subjective

---------- Post added 07-08-21 at 12:41 PM ----------

Aren't equivalence discussions fun?

The only thing I would say is that if your mount stays really big (like the z mount), even if the sensor size is smaller, the lenses for APS-C probably aren't going to be that much different in size. .

APS lenses are smaller in most cases because you use a 50% shorter focal length for the same angle of view as with FF. Eg you use a 200mm lens on APS and a 300mm lens on FF to get the same angle of view. Eg the 150-450 give the angle of view of a 693mm lens on FF. A 700mm lens is huge.....

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Last edited by Pål Jensen; 07-08-2021 at 03:53 AM.

[Rondec]

Lenses with the same angle of view for different formats can never be fully equivalent. The equivalence crowd is ignoring this fact and state that only DOF wide open matters, something that is a completely subjective opinion. We had no equivalence discussion in the film days as everyone understood that using a Pentax 6X7 over an LX wasn't because you could use 64000ISO in the former to get the same output as the latter at 100ISO. 1.4 is never equivalent to F.2. Just ask any lens manufacturer.
The equivalence misunderstanding is based on the false assumption that you want the same output from two different formats and wrongly insisting that the lens aperture is defined by the lens DOF

---------- Post added 07-08-21 at 12:35 PM ----------



Or gaining. All you do when comparing lenses with same angle of view from two different formats is transposing the DOF scale towards deeper DOF on the smaller format. What DOF range is most desireable is 100% subjective and depends on subject and what effect you want to create. The assumption that paper thin DOF is always desirable is false in most cases as most successful images require some DOF. and is anyway purely subjective

---------- Post added 07-08-21 at 12:41 PM ----------



APS lenses are smaller in most cases because you use a 50% shorter focal length for the same angle of view as with FF. Eg you use a 200mm lens on APS and a 300mm lens on FF to get the same angle of view. Eg the 150-450 give the angle of view of a 693mm lens on FF. A 700mm lens is huge.....

Yes. But the question is whether you convert just the focal length or the aperture too. I think you should convert the aperture, so the DA *55 is not exactly the same on a K-3 as the DFA *85 f1.4 would be on a K-1, even though angle of view will be similar. I prefer the full frame rendering of the 85, even though I like the DA *55 quite well too.

Yes, the angle of view is cropped on APS-C, but if you compare a 61 megapixel full frame (A7r IV) to a K3, you don't get any extra length at all to your lenses. So, this cropped angle of view doesn't mean much. If you shoot with your hypothetical 450mm lens on APS-C and 700 mm on full frame with the same pixel density, you have the ability to crop down the full frame to the APS-C image, just not the reverse.

[awscreo]

A bit of a desperate move imo.. But looks pretty nice, although ergonomically not ideal. If I was looking for a retro styled mirrorless, it'd be difficult not to get a fuji at this point..

[Pål Jensen]

Yes. But the question is whether you convert just the focal length or the aperture too. I think you should convert the aperture, so the DA *55 is not exactly the same on a K-3 as the DFA *85 f1.4 would be on a K-1, even though angle of view will be similar. I prefer the full frame rendering of the 85, even though I like the DA *55 quite well too.

Yes, the angle of view is cropped on APS-C, but if you compare a 61 megapixel full frame (A7r IV) to a K3, you don't get any extra length at all to your lenses. So, this cropped angle of view doesn't mean much. If you shoot with your hypothetical 450mm lens on APS-C and 700 mm on full frame with the same pixel density, you have the ability to crop down the full frame to the APS-C image, just not the reverse.

You convert neither focal length or aperture. They are fixed. They cannot be converted as they are measurable physical properties. It is all about angle of view.
Nobody claims that you cannot get APS style images from an FF camera. However, if you crop a FF image to APS size you are not comparing APS to FF anymore but APS to APS. One of them a waste of money, size and pixels.

To illustrate how subjective and situation dependent the so called objective equivalence is can be illustrated by an example:
Say, you are an astro photographer taking images of the milky way with your APS 1.4 lens. Then you figure out that you can actually rather use FF and an F:2 lens, which is much cheaper, according to equivalence. To your surprise you find that either the shutter speed gets one stop longer giving streaks and comparable to the use an F.2 lens for APS, or you have to boost ISO one stop loosing the noise advantage you presumable bought the FF camera for in the first place. There's simply no equivalence of free lunch. If you want that FF advantage over APS for this situation you have to use an F:1.4 on FF as well. What parametres you find important when comparing formats and lenses is purely subjective....

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Last edited by Pål Jensen; 07-08-2021 at 07:54 AM.

[AgentL]

Aren't equivalence discussions fun?

In fact, they are not.

[Jonathan Mac]

Whether or not you should convert APS-C focal lengths/field of view and aperture depends on the usage of the equipment, something that many people do not understand.

[i_trax]

Nikon Japan: Some Z fc camera shipments delayed, 28mm F2.8 orders delayed indefinitely

translation:
Thank you for your continued patronage of Nikon products.
We are pleased to inform you that the release date of the APS-C size (Nikon DX format) mirrorless camera "Z fc" and related products, which was announced to be released in late July 2021, has been decided.
In addition, we have received a large number of reservations for "Z fc" and "Z fc 16-50 VR SL Lens Kit", which exceeds our expectations. For some customers who are currently making reservations, it may take some time before the product is delivered.
We sincerely apologize for any inconvenience caused to customers who are waiting for our products.
We will do our utmost to deliver the product as soon as possible, and we appreciate your understanding.


The "Z fc 28mm f / 2.8 Special Edition Kit", which is scheduled to be released in late July 2021, has received a large number of reservations beyond expectations, and due to the delay in parts supply, the supply amount is sufficient for release. Is not expected to be available.
Therefore, we have decided to postpone the release. We will inform you of the release date as soon as it is confirmed.
We sincerely apologize for any inconvenience caused to customers who are waiting for our products.
We will do our utmost to deliver the product as soon as possible, and we appreciate your understanding.

[Mbaez]

Nikon Japan: Some Z fc camera shipments delayed, 28mm F2.8 orders delayed indefinitely

translation:
Thank you for your continued patronage of Nikon products.
We are pleased to inform you that the release date of the APS-C size (Nikon DX format) mirrorless camera "Z fc" and related products, which was announced to be released in late July 2021, has been decided.
In addition, we have received a large number of reservations for "Z fc" and "Z fc 16-50 VR SL Lens Kit", which exceeds our expectations. For some customers who are currently making reservations, it may take some time before the product is delivered.
We sincerely apologize for any inconvenience caused to customers who are waiting for our products.
We will do our utmost to deliver the product as soon as possible, and we appreciate your understanding.


The "Z fc 28mm f / 2.8 Special Edition Kit", which is scheduled to be released in late July 2021, has received a large number of reservations beyond expectations, and due to the delay in parts supply, the supply amount is sufficient for release. Is not expected to be available.
Therefore, we have decided to postpone the release. We will inform you of the release date as soon as it is confirmed.
We sincerely apologize for any inconvenience caused to customers who are waiting for our products.
We will do our utmost to deliver the product as soon as possible, and we appreciate your understanding.

Well, for Nikon is kind of a tradition to struggle with demand even before COVID.

[Angelic Layer]

Around $1182 USD.
Dimension comparison with FM2.

[Mbaez]

Around $1182 USD.
Dimension comparison with FM2.

Pretty cameras.

[Wasp]

Dimension comparison with FM2.

For a moment I thought it was some sort of focal length equivalence thing, but it did not make sense.

[pres589]

Wondering what lens and lens cap (odd thing to care about?) are mounted to that FM2. Looks like a nice little setup.

[AgentL]

Around $1182 USD.
Dimension comparison with FM2.

That FM2 looks so cool!

[Jonathan Mac]

Around $1182 USD.
Dimension comparison with FM2.

I have to admit some of those colours look nice. The orange one would be my pick.

[Serkevan]

Wondering what lens and lens cap (odd thing to care about?) are mounted to that FM2. Looks like a nice little setup.

I'm gonna go out on a limb and say it's the Nikkor 45mm f/2.8P.

https://www.kenrockwell.com/nikon/images1/45-p/D3S_5313-600.jpg