[kasey]

do any of you here have the cameras that frank was selling, K100D's that were converted for IR only?

would like to discuss lenses you're using.

we found out the 16/45 has a lovely hot spot. both of our 50mm (1.7 and 1.4) appear to test well. the 77 has no hint of one at f8. the 50/135 might earn legendary status with color but it is horrible for IR. the FA*300 seems to be fine, have not tested the DA*300 yet.

we have purchased 18/55 lenses as we're told those work well. has anyone tested any other lenses on these bodies?


kasey

[alohadave]

I can confirm for sure that the 18-55 kit lens (version 1) is great for IR. No hotspots that I've seen.

[creampuff]

Hot spot friendly? Those that I know...

Pass - No hot spots

DA 14mm
DA 18-55mm
DA 18-55mm II
DA 21mm
DA 50-200mm
FA 28-200mm
FA 50mm f/1.4
FA 28mm
FA 77mm
DA* 300
Sigma 28mm f/2.8 (manual focus)
Lensbaby II

Fail - Clear or varying degree of hot spots

DA 16-45mm (clear irregular hotspot)
DA 12-24mm (slight, when stopped down in bright conditions)
DA* 50-135mm (slight)
FA 50mm Macro (slight, noticeable when stopped down)
DFA 50mm Macro (very slight up to f/4, worsens when stopped, better than FA 50mm macro)
Sigma 10-20mm (depends on scene)


Please add to the list if you've tested a lens that's IR friendly.

[Gilgond]

I'm not sure what to look for, but the DA 35 Macro has worked well for me:

[kasey]

appreciate the replys.

Infra-Red With Digital cameras
is a good site and also explains how to deal with hot spots so might explain what one is.

here's another site
Causes of Hot Spots - ClubSNAP Photography Forums

these come from frank.


kasey

PS lets keep the list of lenses that work (and don't work) going.

[kasey]

more interested in the 90-105mm range but information on any macro lens for IR would be of interest.


creampuff, which of the lenses not giving hot spots are giving you the best IQ?


kasey

[minavasht]

I just got my copy, tested with FA 28mm, FA 50mm f1.7 and FA 28-70mm f4 - all work great, no hot spots. In my previous experience with DL and hoya filter 18-55mm (ver 1) works great too, just a tad soft.
28mm is not wide enough for me, I gues I have to buy a 18-55mm again and hope for a sharper copy .

[kasey]

tested the sigma 180mm macro -- nope, hot spots, darn!

the DA*300mm f4 looks ok, whew.

anyone tried a macro other than the 35mm gilond says is ok? 50mm?


kasey

[kasey]

since i have not used a number of the lenses we have listed as working with with the IR converted cameras i'd like to know your opinion of the IQ from these lenses. IQ equates first, to me, as sharpness. if it isn't sharp the rest doesn't matter......

of the lenses listed i have the FA 50mm 1.4 and 77mm. both of course are very sharp. my husband has the 50mm 1.4 and it is sharp. i personally prefer AF lenses to MF.

we all know that generally the 18/55 and 50/200 tend to be a little soft.

so what about the others below? thanks for your input.

kasey

DA 21
M 20 f4
FA 28mm,
FA 28-70mm f4
DA 35 Macro
DA 21mm
FA 28-200mm
Sigma 28mm f/2.8 (manual focus)

I have tried:

Kit lens 18-55 ver 1: Perfect

Tammy 18-250: no hot spot and reasonably good AF at the long end and close ups. The wide end AF is all around but I would say that it would be too much to ask to debug the AF to make the lens work OK on the whole range

Sigma 10-20 : mild hot spot but it is there.

Fa50 f1.4: no hot spot but I didnt use it too much yet.

[creampuff]

more interested in the 90-105mm range but information on any macro lens for IR would be of interest.

creampuff, which of the lenses not giving hot spots are giving you the best IQ?

kasey

Personally, I like the DA 14mm that I just tried out. Lovely lens.
Some images taken with it. IR walkabout with the DA 14

Most of the older lenses, especially prime lenses don't exhibit hot spots. But most are not AF, so focusing can be a little more challenging. For a lens in the range you've mentioned, the DA 50-200mm is a good versatile lens both for normal and IR photography and doesn't hurt the wallet.
The Pentax macro lenses I've tried aren't too IR friendly.

You can improve IQ by shooting at a low ISO and getting the exposure right. I've had no problems with sharpness with lenses I've mention in my list, except perhaps the Lensbaby.