[daacon]

Not sure if this belongs in the Lens, Body or Accessories section but since I am asking about a lens I figured this is a good as any.

I am getting and IstD soon (Thanks to Gruoso) for many reasons including experimenting with Infrared photography. From what I have read here I will need a Hoya R72 filter it that the best ?

My question is what lens would be best or does it even matter ? I was thinking the wider the better but not sure. Along with the lenses in my sig the istD will be comming with the kit lens 18-55.

thx.............Dave

[Buddha Jones]

I would stick with the kit lens and yes the Hoya R72 is the best.

[Wheatfield]

Not sure if this belongs in the Lens, Body or Accessories section but since I am asking about a lens I figured this is a good as any.

I am getting and IstD soon (Thanks to Gruoso) for many reasons including experimenting with Infrared photography. From what I have read here I will need a Hoya R72 filter it that the best ?

My question is what lens would be best or does it even matter ? I was thinking the wider the better but not sure. Along with the lenses in my sig the istD will be comming with the kit lens 18-55.

thx.............Dave

Use whatever lens is best suited to what you are photographing. IR photography is not lens dependant. You do need an IR cut filter on it though, so get one that will fit the biggest lens front you have, and then use stepper rings to go to smaller optics.
This does increase the possibility of flare off the filter, since you can end up with an 82mm filter on a 49mm filter ring, if that is the range of sizes you have, but unless you want to buy a bunch of specialty filters, it's the best you can do.

[TourDeForce]

Use whatever lens is best suited to what you are photographing. IR photography is not lens dependant.

I'm not sure that is true. This marketplace ad has a nice discussion about IR photography:
https://www.pentaxforums.com/forums/photographer-s-marketplace/19689-fs-ir-on...ir-filter.html
It also includes a link to a listing of lenses that are known to work well, and others that display 'hot spots':
DPanswer: Digital Infrared Resource page

[daacon]

Thanks Guys. James appears to be corect from the link TourDeForce gave me Frank suggests the kit lens is indeed the most IR friendly. Now this is for a convereted camera and not a front filter still I think that is a good place to start (or maybe I need to have the istD convereted or buy a k100d convereted) ....ummmmm

[TourDeForce]

If you plan to do stills on a tripod, the filter on camera will give you a feel for the techniques involved and results you can achieve. You'll need relatively long exposures in most cases.

If you're serious about getting into IR, then a converted camera is a must.

[Wheatfield]

I'm not sure that is true. This marketplace ad has a nice discussion about IR photography:
https://www.pentaxforums.com/forums/photographer-s-marketplace/19689-fs-ir-on...ir-filter.html
It also includes a link to a listing of lenses that are known to work well, and others that display 'hot spots':
DPanswer: Digital Infrared Resource page

I'm not buying into that. I've shot to much IR film on too many focal lengths with no artifacts to believe it.
To be fair though, I don't use non Pentax lenses, I don't use zooms, and I haven't done much digital IR.

[creampuff]

Use whatever lens is best suited to what you are photographing. IR photography is not lens dependant. You do need an IR cut filter on it though, so get one that will fit the biggest lens front you have, and then use stepper rings to go to smaller optics.
This does increase the possibility of flare off the filter, since you can end up with an 82mm filter on a 49mm filter ring, if that is the range of sizes you have, but unless you want to buy a bunch of specialty filters, it's the best you can do.

I'm not buying into that. I've shot to much IR film on too many focal lengths with no artifacts to believe it.
To be fair though, I don't use non Pentax lenses, I don't use zooms, and I haven't done much digital IR.

First off, shooting IR on digital is quite different than IR on film. There are a large number of IR photographers where I am here in sunny Singapore and from the input of many IR photographers, some lenses do indeed exhibit hot-spotting. This happens across different camera makes. Some lenses, Pentax included do show hot spots. So your first assertion is incorrect.

Secondly, it is not necessary to buy the biggest IR filter diameter and use step-up rings. Such a route is very expensive given the big jump in cost with larger diameter IR filter sizes. I would recommend those starting out to use of the DA18-55mm kit lens which exhibits no hot-spotting and only requires a more affordable 52mm IR filter.

The K100D and ist series of cameras are very IR friendly in that the sensor is quite sensitive and allows quite short exposure times. The K10D sensor is less sensitive and typical exposure times extend to several seconds. This invariably means the use of a tripod. A dedicated IR only camera is obviously the best solution as it's greater IR sensitivity allows the use of shorter shutter speeds, which allows hand holding the camera and allows shots that have subject movement (like people, vehicles, etc.)

Perhaps you should give digital IR photography a try to get a better understanding of it.

[dantuyhoa]

I agree with creampuff .

Dave : just use your kit lens .

Have the camera on tripod .
Set the ISO to the lowest . Aperture to F16 or so .

Compose your image . Focus then slowly put on your R72 .
Use the remote or cable switch to minimize the camera shake .

I carry a lens cloth to clean the lens and filter the last minute . It's a long exposure so anything dirty will show up on your photo . Make sure you cover the viewfinder with the cap before firing .

Here is one with the DS at ISO 200 , F16 , 1.5 sec :




You can use the K10D too . I use it in B mode . Just use you watch . Very much the same set up . Compose , focus then switch to the B mode . Count and pray . I believe in multi Gods . Just like a muti life insurance policies , j/k .

I shoot on K10D with different timing for each image . After a while you will have somewhat of a timing down .

K10D with FA50/1.4 ,ISO 100 , F16 , 108 sec :



If you leave the ISO on AUTO , it will pick up a higher setting so less exposure time . But I prefer to set it in lower ISO for less noise .

More images at

Infrared - a set on Flickr

Good luck and have fun .

Tran