[UncleVanya]

New unsold old stock on both those lenses? They look totally pristine.

I notice that the 300mm has a slide-forward lens hood, By far my favorite design for that accessory. Most convenient to use in every way, no competition superior to any and all other designs I've used.

Two problems with built in slide out hoods:
1) Not narrow enough on crop.
2) Friction doesn't hold up over time and the hood tends to slide back closed as you tilt up the lens.

[BigMackCam]

2) Friction doesn't hold up over time and the hood tends to slide back closed as you tilt up the lens.

... except on Soviet lenses, where you're lucky if you can pull the hood out at all without it binding on the body. And if you do, it's invariably too short to help on *any* size of sensor

[WPRESTO]

Two problems with built in slide out hoods:
1) Not narrow enough on crop.
2) Friction doesn't hold up over time and the hood tends to slide back closed as you tilt up the lens.

Nothing seems to be perfect, every design seems to involve compromises, when a design gains something good, it seems to lose something valuable from the deign it's replacing. The slide-hood on my very old 200mm f4 SMCA ED macro still works exactly as it should, no problems or complaints. But modern some tulip-hoods I have very quickly wore down the little locking tabs that snapped and held them in place, so they are loose and even prone to falling off, especially on the 55~300mm the hood for which has been repaired by me twice, adding a specks of glue to the locking tabs so it would snap on as intended, only to have the glue wear off. A couple of MFT lenses I have from Olympus have a good design I've not seen before. The hood has a push-button that must be depressed to release the hood from either storage or in-use position. I suspect the mechanism will last longer than the twist-it's-on tabs so ubiquitous on tulip-hoods.

[UncleVanya]

Nothing seems to be perfect, every design seems to involve compromises, when a design gains something good, it seems to lose something valuable from the deign it's replacing. The slide-hood on my very old 200mm f4 SMCA ED macro still works exactly as it should, no problems or complaints. But modern some tulip-hoods I have very quickly wore down the little locking tabs that snapped and held them in place, so they are loose and even prone to falling off, especially on the 55~300mm the hood for which has been repaired by me twice, adding a specks of glue to the locking tabs so it would snap on as intended, only to have the glue wear off. A couple of MFT lenses I have from Olympus have a good design I've not seen before. The hood has a push-button that must be depressed to release the hood from either storage or in-use position. I suspect the mechanism will last longer than the twist-it's-on tabs so ubiquitous on tulip-hoods.

Interesting. I have no hoods that are removable that have become loose except for my FA* 300 which is a little loose.

[Canada_Rockies]

Two problems with built in slide out hoods:
1) Not narrow enough on crop.
2) Friction doesn't hold up over time and the hood tends to slide back closed as you tilt up the lens.

The M 400 has problem 1, of course, but problem 2 is solved by the "gun sight" that screws down to hold the hood in place as well as making it easier to aim the bazooka (as a couple of interpreters at the Creston Wildlife area called it).

[Boris_Akunin]

New unsold old stock on both those lenses? They look totally pristine.

I wouldn't think so, the 24 only has a few very fine scratches but the focus ring has about 1mm of play (that is unfortunately very common with the nFD lenses, it's due to the linkage between the focus ring an the helicoid wearing out but it has no impact on IQ), the 300 actually is pristine. I don't think either of them has been used much, I'll exchange it for my other nFD300/5.6 (no issues but slight signs of use) and sell that one.
My other 24/2.8 has few more signs of use than this one but slighty less play in the focus ring, so I'll b selling the new one.

[Boris_Akunin]

Two problems with built in slide out hoods:
1) Not narrow enough on crop.
2) Friction doesn't hold up over time and the hood tends to slide back closed as you tilt up the lens.

Clear advantages:
- You can't lose them or forget them at home.
- They don't take up a meaningful amount of space when you don't use them

Possible advantages:
- They don't necessarily collide with filters & lens caps (if you use the right kind of lens cap) like screw-in and clip-in hoods
- Variable length (if they have enough friction to stay in place)

Disadvantages:
- Their length and shape is restricted by the design of the lens barrel (this one's quite ample but they're often too short)


I had a full set of Canon nFD lenses with 52mm filter threads for a while (24/2, 28/2, 35/2, 50/1.4, 85/1.8, 100/2), they all used the same hood bajonet and while they all had dedicated hoods (BW-52C, BW-52B, BW-52A, BS-52, BT-52),
the hoods were all interchangeable, a 24mm hood still gives some protection on a 35 or 50 and a somewhat longer hood still works on a wider lens (exchanging more soft vignetting for extra flare protection).

Unfortunatelly, only the BW-52C and BW-52B had petal shapes, I would have liked some longer petal hoods (I know the petal hood for e.g. the 100/2 would be quite long but I could always use one of the shorter ones).

Ideally, some lenses would have oversized bajonet mounts, so hoods could be intercompatible across a wider range of lenses.
The Canon nFD 135s & 200s don't have hood bajonets but the 52mm filter thread spans from 24mm to 200mm (within that range, only the 35/2.8 tilt-shift and the 85/1.2 have larger threads), so the lens caps are all interchangeable, so could the hoods be.

A (mostly) universal hood bajonet would add some bulk to the smaller lenses but I think that would be well worth it.



(Canon nFD nFD 300/5.6, 100/2, 50/1.4, 35/2, 28/2 & 24/2.8)


EDIT: Dammit, now my brain has latched on to the standardisation idea...


First, we'll adjust the most common prime focal lengths a bit to deal with the crop issue:

(10) - 15 - 23 - 35 - 55 - 85 - 130 - 200 - 300 - (450)

The ratios between the steps are now all between 1.5 and 1.57, so to get an APS-C lens hood for your FF lens, you just buy the hood for the next-longer prime lens.
A secondary set of steps could look like this (ratios between 1.5 and 1.56):

(13) - 20 - 30 - 45 - 70 - 105 - (160) - (240) - (360)

The lens hood bajonet needs to be slightly larger than the filter thread anyway, so we tie the two together.
Something like 77mm across the board would add too much bulk to all the smaller lenses but we do want 85/1.4's and 130/2's.
72-82mm would work as the largest thread (with a corresponding hood bajonet), we should be able to cover anything from 20/1.4 to 130/1.8.

Next we'll need a thread size that can cover anything except the largest primes, things like a 35/1.4, 55/1.4 and 85/1.8 should fit here.
Something like 58-67mm should have us covered, a prime lineup like this should be possible:

20/2.8 - 23/2 - 30/1.8 - 35/1.4 - 55/1.4(1.2?) - 85/1.8 - 105/2 - 130/2.4

As for zooms, a 15-35/4 or 23-105/4 would probably need the larger thread/bajonet but a 23-70/4 & 70-200/4 as well as variable-aperture lenses like 20-45/3.5-4.5, 23-130/3.5-5.6 or 70-300/4-5.6 would fit here.

I'm not sure if we'd really need a small 3rd standard but a set of small primes (with diameters around 65mm and below) with 49-55mm threads could work:

23/2.8 - 30/2 - 35/1.8 - 55/1.8 - 85/2 - 130/2.8(3.5?)

Overall, we should leave some room for lens design and pick the larger side for all 3 standards (55mm, 67mm, 82mm).
Apart from extreme wide angle lenses and fast tele lenses (105/1.4, 200/2, 400/2.8, 200-400/4, etc.), we'd have everything covered and would never need filters or lens caps in any but these 3 sizes.

There would be some options for backward compatibility, e.g. step-up rings with bajonet hoods on the outside to bring old lenses into the new standard.

---

Last edited by Boris_Akunin; 07-19-2018 at 03:10 PM.

[Liney]

Hopefully someone can enlighten me, but why are some hoods just round, and some like the second from the right have some sections that extend further than others? And what is the best way to orient these crenelated ones?

[clackers]

Hopefully someone can enlighten me, but why are some hoods just round, and some like the second from the right have some sections that extend further than others? And what is the best way to orient these crenelated ones?

The long flower petals at the top and bottom, the shorter ones at the sides, Liney.

[ivanvernon]

Hopefully someone can enlighten me, but why are some hoods just round, and some like the second from the right have some sections that extend further than others? And what is the best way to orient these crenelated ones?

Most of the time you are shooting in a format that is wider than the height. The shorter petals on the side allow maximum coverage without vignetting, while the longer petals on top permit a lesser amount of coverage consistent with the rectangular format.

[UncleVanya]

Hopefully someone can enlighten me, but why are some hoods just round, and some like the second from the right have some sections that extend further than others? And what is the best way to orient these crenelated ones?

This should help...

Understanding Camera Lens Flare

[Boris_Akunin]

hopefully someone can enlighten me, but why are some hoods just round, and some like the second from the right have some sections that extend further than others? And what is the best way to orient these crenelated ones?

The LKUs have somewhat more variance than I had hoped (1 LKU = 4.8 ± 0.2 mm), this will also limit stackability but - with proper alignment - only in the upper reaches of the required range.


To demonstrate the range:


Samyang FE35/2.8: ~10LKU (~7LKU from the lens mount) | Canon nFD300/5.6: ~44LKU (~41LKU from the lens mount)


With proper unit alignment, even fully erect lenses can be measured:


Canon nFD300/5.6 with hood extended: ~56LKU (~53LKU from the lens mount)


Here's the new Samyang with it's valiant (but somewhat bloated) AF ally to the left and the MF rivals it's trying to expel to the right:


Sony FE85/1.8: ~19LKU | Samyang FE35/2.8: ~10LKU | Canon nFD35/2 (with FE adapter): ~16LKU | Pentax K28/3.5 (with FE adapter): ~17LKU
Those values include Sony E-mount rear lens caps (~3LKU) and the E-mount adapters on the Canon (~4LKU) and Pentax (~5LKU).

[aslyfox]

remember that when trying to show scale ( length and width ) paper currency is uniform ( depending on what it is dollar bill or other ) and usually easily duplicated

2.6 Inches by 6.1 Inches are the dimensions for the U.S. dollar bill.

[Boris_Akunin]

remember that when trying to show scale ( length and width ) paper currency is uniform ( depending on what it is dollar bill or other ) and usually easily duplicated

2.6 Inches by 6.1 Inches are the dimensions for the U.S. dollar bill.

Great idea! I'll just PM you my address, so you can send me that 27.3cm stack of dollar bills...

[monochrome]

Lku = amu