IR filter and hoods

[hammam]

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Forgive me if this a basic technical question, but all this IR issue is new to me. Is the need of a hood to prevent flare (protection notwithstanding) as important when using an IR filter? I would never be caught without some kind of a hood in front, especially since I never use UV filters, but with an IR filter?. Some people might use step-up rings if they have several filter size lenses, and I guess the hoods may become problematic.

 

Thanks for your lights on the matter.

[erl]

Hammam, you question is very valid, aspecially with some of the notoriously short Leica shades. The front surface of any filter comes that much further forward and, especially on the Noctilux, almost renders the shade useless.

 

Probably the only effective cover is some after market hood, but then you start protruding far into the VF. Don't know a definitve solution. Others may.

 

Cheers,

Erl

[jaapv]

Hammam, you question is very valid, aspecially with some of the notoriously short Leica shades. The front surface of any filter comes that much further forward and, especially on the Noctilux, almost renders the shade useless.

 

Probably the only effective cover is some after market hood, but then you start protruding far into the VF. Don't know a definitve solution. Others may.

 

Cheers,

Erl

 

Actually, I doubt that the hood on my 24 will even fit over a filter without modification. Has anybody got experience on this? With the Summicron 2.0 35 Heavystar offers a very beautiful screw-in vented hood, designgned for 50 mm so just right for the M8.

[robsteve]

Actually, I doubt that the hood on my 24 will even fit over a filter without modification. Has anybody got experience on this? With the Summicron 2.0 35 Heavystar offers a very beautiful screw-in vented hood, designgned for 50 mm so just right for the M8.

 

My B+W 486 filters arrived yesterday and I tried one on the 24mm and the hood fit on fine. With a filter fitted, the hood is a bit more difficult to mount because you have to keep it perfecly parallel when mounting or it binds a bit against the filter.

 

Some filter are too big in diameter and the hood will not fit over them, but it typically hasn't been a problem with B+W filters.

[ho_co]

Olivier--

As hinted at by posts above:

 

The idea of a hood is to keep non-image-forming light out of the lens. Whether you choose to use the IR-cut filter or not, anything that helps keep extra light out of the system will be helpful.

 

Optically, the IR-cut filter is simply another piece of glass in front of the lens, so in regard to being able to cause flare, it will act the same way. Most of the time, the IR-cut will cause only improvement, but occasionally it may cause internal reflections.

 

So in my opinion, the hood is *more* necessary with the filter than without.

 

--HC

[sean_reid]

Actually, I doubt that the hood on my 24 will even fit over a filter without modification. Has anybody got experience on this? With the Summicron 2.0 35 Heavystar offers a very beautiful screw-in vented hood, designgned for 50 mm so just right for the M8.

 

The standard Leica hood still fits on a 24/2.8 with a Heliopan IR-cut filter mounted. Don't have a 55 mm version of the 486 to try yet.

 

All,

 

The hoods still seem to provide much of their usual function even with the filter on. I wouldn't worry too much about function, fir may or may not be an issue with some lenses.

 

Cheers,

 

Sean